P:\~Sales and Marketing\Publications\Manuals and Handbooks\Current Manuals\500 Isokinetic Handbook - Rev 8 - TRO (10.18.18).docx
APEX INSTRUMENTS, INC.
Isokinetic Source Sampling Handbook
Isokinetic
Handbook
2
ISOKINETIC SOURCE SAMPLING
Isokinetic Handbook
Apex Instruments, Inc.
204 Technology Park Lane
Fuquay-Varina, NC 27526 USA
Phone 919-557-7300 • Fax 919-557-7110
Web: www.apexinst.com
E-mail: [email protected]
Revision No: 8
Revision Date: October 2018
3
TABLE OF CONTENTS
Chapter 1: Introduction ................................................................................................................................... 5
System Description ......................................................................................................................................... 7
Source Sampler Console ............................................................................................................................. 8
Electrical Subsystem .............................................................................................................................. 8
Thermocouple Subsystem ...................................................................................................................... 8
Vacuum Subsystem ................................................................................................................................ 9
External Vacuum Pump Unit .................................................................................................................... 11
Probe Assembly ........................................................................................................................................ 12
Probe Liner ........................................................................................................................................... 13
Probe Heater ......................................................................................................................................... 14
Modular Sample Case ............................................................................................................................... 16
Umbilical Cable with Umbilical Adapter ................................................................................................. 17
Glassware Sample Train ............................................................................................................... 18
Chapter 2: Operating Procedures ................................................................................................................. 19
Set-up and Check of Source Sampling System............................................................................................. 19
Initial Set-up Procedure ............................................................................................................................ 19
Initial Sampling System Leak Check ........................................................................................................ 21
Test Design ................................................................................................................................................... 22
Site Preparation ............................................................................................................................................. 22
Mount the Filter Oven and Impinge Assembly............................................................................................. 25
Assemble Sampling Equipment and Reagents ............................................................................................. 28
Preliminary Measurements of Gas Velocity, Molecular Weight and Moisture............................................ 28
Method 1 – Determining Sample and Velocity Traverse Points .................................................................. 30
Determining Traverse Points .................................................................................................................... 31
Method 1A – Sample and Velocity Traverses for Small Stacks or Ducts .................................................... 37
Method 2 – Stack Gas Velocity and Volumetric Flow Rate ......................................................................... 39
Stack Gas Molecular Weight and Moisture .............................................................................................. 40
Using the Pitot Tube ................................................................................................................................. 41
Determine Flow Rate ................................................................................................................................ 41
Static Pressure ........................................................................................................................................... 44
Barometric Pressure .................................................................................................................................. 44
Calculate Volumetric Flow Rate ............................................................................................................... 44
4
Method 3 – Gas Analysis for Dry Molecular Weight ................................................................................... 46
Determine Dry Molecular Weight ............................................................................................................ 48
Method 4 – Moisture Content of Stack Gas.................................................................................................. 49
Reference Method 4 .................................................................................................................................. 51
Approximation Method ............................................................................................................................. 53
Calculating Stack Gas Moisture Content .................................................................................................. 55
Method 5 – Determination of Particulate Emissions .................................................................................... 56
K-Factor Calculations ............................................................................................................................... 58
Method 5 Test Procedure .......................................................................................................................... 59
Recommended Reading List for Isokinetic Sampling .................................................................................. 70
Chapter 3: Calibration and Maintenance .................................................................................................... 71
Calibration Procedures .................................................................................................................................. 71
Dry Gas Meter and Orifice Tube .............................................................................................................. 73
Metering System Leak Check Procedure (Vacuum Side) .................................................................... 73
Metering System Leak Check Procedure (Pressure Side) .................................................................... 74
Initial or Semiannual Calibration of Dry Gas Meter and Orifice Tube ................................................ 75
Post-Test Calibration of the Source Sampler Console ......................................................................... 78
Calibration of Thermocouples .................................................................................................................. 79
Calibration of Pitot Tube ........................................................................................................................... 80
Calibration of Sampling Nozzles .............................................................................................................. 82
Initial Calibration of Probe Heater ............................................................................................................ 83
Calibration of Pressure Sensors ................................................................................................................ 84
Maintenance .................................................................................................................................................. 85
Appendix A ...................................................................................................................................................... 86
Recommended Equipment for Isokinetic Sampling ..................................................................................... 87
Recommended Spare Parts ........................................................................................................................... 90
Equipment Checklist ..................................................................................................................................... 92
Appendix B ...................................................................................................................................................... 93
Calibration Data Sheets................................................................................................................................. 94
Appendix C .................................................................................................................................................... 102
Stack Testing Field Data Sheets ................................................................................................................. 103
Appendix D .................................................................................................................................................... 113
Calculation Worksheets .............................................................................................................................. 114
5
Chapter 1
Introduction The purpose of this manual is to provide a condensed understanding of the procedures established by the
United States Environmental Protection Agency (US EPA) in accordance with Reference Methods 1 through
5 – Determination of Particulate Emissions from Stationary Sources.
In addition to providing an easy-to-use guide for Methods 1 through 5, we have provided users with reference
information on system configuration, calibration procedures, maintenance and troubleshooting. Be on the
lookout for helpful tips and training aids throughout this manual.
We trust you will find this guide useful regardless of the sampling equipment you use and will use our
equipment for demonstrations and illustrations.
Isokinetic Sampling is the collection and measurement of a gas sample from a source at the same velocity as
the gas travels in the stack to provide a representative assessment of solid particulate matter that is in the
source.
To perform isokinetic testing, you must have a thorough understanding of the first five test methods presented
in Title 40 Part 60 Appendix A of the Code of Federal Regulations (40CFR60 App. A). While Method 5
outlines the general sampling train operation protocol, Methods 1 through 4 prescribe techniques that serve as
a foundation for Method 5 sampling activities. Together, these methods outline the basic protocols for
determining particulate concentrations and mass emission rates.
US EPA Method
Description
Method 1 Determination of Sampling Location and Traverse Points
Method 2 Determination of Stack Gas Velocity and Volumetric Flow-rates
Method 3 Determination of Dry Molecular Weight and Percent Excess Air
Method 4 Determination of Moisture Content
Method 5 Determination of Particulate Matter Emissions from Stationary Sources
6
You can easily adapt the basic Method 5 sampling train to test for many other gaseous and particulate emissions
from stationary sources. Adapting basic test methods allow you to expand testing to include parameters of
interest such as metals, polychlorinated biphenyls (PCBs), dioxins/furans, polycyclic aromatic hydrocarbons
(PAHs), particle size distributions and an ever-increasing group of other pollutants.
While the different methods are designated by other US EPA method numbers, they actually are variations of
Method 5 procedures. Variations might include using different impinger solutions, organic resin traps, different
filter media, various sampling temperatures, or a range of other alternative procedures.
The manual and the automated source sampling consoles can be used for the following isokinetic test
methods and pollutants:
Method No. Pollutants
5A PM from Asphalt Roofing 5B Non-sulfuric Acid PM 5D PM from Positive Pressure Fabric Filters 5E PM from Fiberglass Plants 5F Non-sulfate PM from Fluid Catalytic Cracking Units 5G PM from Wood Stoves - Dilution Tunnel 5H PM from Wood Stoves – Stack 8 Sulfuric Acid Mist, Sulfur Dioxide and PM
12 Inorganic Lead (Pb) 13A & 13B Total Fluorides
17 Particulate Matter 23 Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans
26A Hydrogen Halides and Halogens 29 Multiple Metals
101 Mercury (Hg) from Chlor Alkali Plants 101A Mercury (Hg) from Sewage Sludge Incinerators 104 Beryllium (Be) 108 Inorganic Arsenic (As) 111 Polonium-210
201A PM10 Particulate Matter (Constant Sampling Rate) 202 Condensable Particulate Matter 206 Ammonia (Tentative) 207 Iso cyanates (Tentative) 306 Hexavalent Chromium from Electroplating and Anodizing Operations 315 PM and Methylene Chloride Extractable Matter (MCEM) from Primary Aluminum
Production 316 Formaldehyde from Mineral Wool and Wool Fiberglass Industries (Proposed)
Waste Combustion Source Methods in EPA-SW-846 Method No. Pollutants
0010 Semi volatile Organic Compounds 0011 Formaldehyde, Other Aldehydes and Ketones
0023A Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans 0050 Hydrogen Chlorine and Chlorine 0060 Multiple Metals 0061 Hexavalent Chromium
7
System Description
The first step to successful sampling is to familiarize yourself with the standard equipment. To illustrate the
necessary components of source sampling, we’ve included a diagram of the five main components
demonstrated on the Apex Instruments Isokinetic Source Sampling System, shown in Figure 1-1:
1. Source Sampler Console, which includes a differential pressure transducer (or dual-column
manometers), sample flow control valves with orifice flow meter, dry gas meter, and electrical
controls.
2. Sample Pump External Rotary Vane (or internal diaphragm pump) , including hoses with quick-
connect fittings and lubricator.
3. Probe Assembly includes a stainless-steel probe sheath, probe liner, tube heater, Type-S pitot tube,
stack and heater thermocouples, and an Orsat line.
4. Modular Sample Case includes a filter oven for the filter assembly, an impinger case for the
impinger glassware and electrical connections.
5. Umbilical Cable includes electrical and pneumatic lines to connect the Modular Sample Case to the
Source Sampling Meter Console.
Figure 1-1: Apex Instruments Isokinetic Source Sampling Equipment
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Description of Component Parts
1. Source Sampler Console
The Source Sampler Console is the operator’s control station. It
monitors gas velocity and temperatures at the sampling location
and controls system sampling rate and system temperatures.
Housed within the console are the Electrical, Thermocouple, and
Vacuum sub-systems.
Electrical Subsystem:
The electrical subsystem provides switched power to several
circuits, including main power, pump power, manometer zero, timer,
probe heater and oven heater. Power rating should be chosen
according to your source of electricity. For example, the Apex
Instruments XC-500 Sampling Systems can be configured for
120VAC/60Hz or 240VAC/50Hz electrical power.
Note: When the main power switch is on, the cooling fan should
operate. Also, the pump has its own power cord, which is plugged
into the Source
Sampler Console.
The electrical system
contains circuit
breakers that detect
and interrupt
overload and short circuit conditions, an
important safety feature. If the circuit
breaker opens or “trips,” indicating
interruption of the circuit, investigate
and repair the electrical fault. Then
Tips from a Stack Tester
To reduce the probability
of nuisance tripping,
follow this start-up
sequence to reduce the
power surge: first, power
up the sample pump
because it runs on the
highest current. Wait a
few seconds after the
pump has started, then
power up the filter and
probe heaters.
Apex Instruments Product Highlight
When looking for a console, consider a user-friendly
design that simplifies field assembly and set-up. The Apex
Instruments XC-500 Series Console Meters place
connections for the sample line, pitot tube lines, vacuum
pump (non-reversible), and electrical (4-pin circular
connector and Thermocouple jacks) all on the front panel
for easy access. You also can remove the front and back
covers of the console to get to what you need. The XC-522
model is programmed for English-standard measurements,
while the XC-572 offers a metric version.
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reset the breaker by pressing the circuit breaker switch. The circuit breaker also can trigger a “nuisance trip,”
making it difficult to complete a test.
The MANOMETER ZERO switch operates two (2) 3-way solenoid valves. When the MANOMETER ZERO
switch is ON, the valves will produce an audible “click.” These valves open both legs of the ΔH side of the
dual-column manometer to atmosphere so that you can check and, if necessary, adjust the manometer fluid
zero pressure level.
The timer will begin to count when the TIMER switch is turned on and stops when the switch is turned off.
The display is reset to zero with a push switch on the face of the timer display. The timer is factory-set to read
hour/minutes/seconds but can read minutes and tenths of minutes if specified in the purchase order.
To activate the heaters in the filter compartment (Hot Box) and the probe heater, turn on the switches labeled
FILTER and PROBE. Adjust the dials to approximately 120°C (248°F) and check the temperature display to
verify that the heaters are working. Allow time for the temperatures to stabilize and then verify operation of
the circuits.
Thermocouple Subsystem:
The thermocouple subsystem displays, measures and provides
feedback for the temperature controls that are critical to
isokinetic sampling operation. The Apex Instruments
thermocouple system consists of Type-K thermocouples,
extension wires, male/female connectors, receptacles, a
thermocouple selector switch, and a digital temperature display
with internal compensating junction.
Existing consoles offer automatic and digitally programmable
temperature controllers for probe and filter oven heat. The
controllers receive temperature feedback signals to maintain
temperatures within range of the set point. The thermocouple
electrical diagram is presented in the electrical schematic, found
in the appropriate operator’s manual.
Vacuum Subsystem:
The vacuum pump assembly provides the vacuum action for
extracting the gas sample from the stack and through the various
components of the isokinetic source sampling system.
Typically, the vacuum subsystem consists of an external
vacuum pump assembly (or internal diaphragm pump), quick-
connects, internal fittings, two (2) control valves (coarse and fine), an orifice meter, and a dual-column inclined
manometer (or pressure transducer).
A popular method of controlling flow is the dual-valve design that helps the operator obtain very precise
control over the sample flow rate through use of the Coarse Control Valve and the Fine Increase Valve.
● The Coarse Control Valve is a ball valve with a 90° handle rotation from closed to full open. This
valve controls the flow from the SAMPLE inlet to the Vacuum Pump inlet.
Tips from a Stack Tester
By observing the orifice
reading (ΔH) on the front
side of the manometer, you
can quickly adjust the
sample flow rate using the
Fine Increase Valve so that
the sample is extracted
under isokinetic conditions.
10
● The Fine Increase Valve is a needle-type valve with four (4) turns from closed to full open. The Fine
Increase Valve allows flow to re-circulate from the pump outlet back to the pump inlet. The Fine
Increase Valve is used for precise vacuum control during leak checks.
You can zero the ΔH manometer before or during a sampling run by flipping on the Manometer Zero switch
found on the front panel. This actuates the solenoid valves to vent the pressure lines to atmosphere. Then, you
can adjust the manometer’s fluid level using the knobs located at the bottom of the manometer.
Figure 1-2 below demonstrated the Apex Instruments Model XC-522 Source Sampler Console’s front panel
to provide an example of the layout of Source Sampling Console.
Did you know? You can zero the pitot tube manometer by disconnecting the pitot
lines at the quick-connects on the Source Sampler Console.
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Figure 1-2: Model XC-522 Source Sampler Console Front Panel
12
Source Sampler Console Front Source Sampler Console Rear
2. External Vacuum Pump Unit
The External Pump Unit provides the vacuum that draws the sample from the stack. The most common type
of pump assembly attaches to the Source Sampler Console via an electrical receptacle and two (2) 1.524 m (5
ft.) hose extensions with 9.525 mm (3/8 in.) quick-connects (configured with a male connector on the pressure
side and a female connector on the suction side.
Figure 1-3: Picture of XE-0523 (Cased) and E-0523
(Open Frame) Lubricated Vane Vacuum Pump
Apex Instruments Product Highlight
Apex Instruments offers two pump styles: the E-
0523 lubricated rotary-vane pump and the
internal diaphragm housed inside the console.
Both pump assemblies are available in either
120VAC or 240VAC operation and customers
can choose from two enclosure options for the
external pump: a black polyethylene case with
molded handles and removable covers or an
aluminum open frame (seen to the right).
• The E-0523 features a 250-watt motor
with a measured flow of 88 lpm and a
maximum vacuum of 86.4 kPa.
13
3. Probe Assembly
The main components of a Probe Assembly are:
● Probe Liner: 15.9 mm (5/8 in.) OD tubing made from either Borosilicate Glass, Quartz, Stainless Steel,
Inconel, or PTFE.
● Probe Heater: Removable rigid tube heater with coiled heating element, electric thermal insulation and
thermocouple, with a maximum recommended temperature of 260oC (500oF).
● Probe Sheath: 25.4 mm (1 in.) OD tube with quad-assembly attached that includes a replaceable,
modular S-type pitot tube, stack thermocouple and a 1/4 in. OD stainless steel tube to collect gas samples
for Orsat analysis.
● Small Parts Kit: Fittings to attach nozzle to Probe Assembly. Fittings include 5/8 in. bored union, nut
and ferrules.
Did you know? The most effective probe length in the stack is equivalent to 0.305 m
(1 ft) less than nominal length. Probe lengths vary from 0.914 m (3 ft) to 4.877 m (16
ft) nominal length.
Tips from a Stack Tester
Pumps that require lubrication, such as the E-
0523, generally are not pre-lubricated and need to
be filled approximately three-quarters (¾) full
with lightweight lubricating oil (Gast AD220,
SAE-10 or SAE-5) before first use.
14
Figure 1-4, right side, illustrates a standard Probe Assembly (top) and a Probe Assembly with the optional 50.8
mm (2 in.) Oversheath and Packing Gland (bottom).
The left part of the diagram shows the connection between the nozzle and probe using fittings from the small
parts kit.
Figure 1-4: Diagrams of Probes and Probe Assembly
Probe Liner:
Standard Probe Liners are constructed from 5/8 in. OD tubing and have #28 ball joints with an O-ring groove.
Available liner materials are borosilicate glass, quartz, stainless steel, Inconel, and PTFE. You will need a ball
joint adapter if you have a PTFE liner, straight liner, or liner with integrated nozzles. Figure 1-5 shows the
potential Probe Liner configurations.
Figure 1-5: Diagrams of Probe Liner Configurations
15
Important: Review maximum operating temperatures before selecting a Probe Liner material and
configuration. Table 1-3 shows the temperature limits for Probe Liner materials, while Table 1-4 reflects
temperature limits for various probe configurations.
Table 1-3: Maximum Stack Gas Temperatures for Probe Liner Materials
Material
Maximum
Temperature
PTFE Liners and Fittings 177°C (350°F)
Glass-Filled PTFE Fittings 260°C (500°F)
Borosilicate Glass Liners 480°C (900°F)
Stainless Steel Liners 650°C (1200°F)
Quartz Liners 900°C (1650°F)
Inconel or C276 Alloy Liners 870°C (1600°F)
Table 1-4: Probe Configuration Temperature Ratings
Probe Assembly Configuration
Maximum
Temperature
Stainless Steel Sheath and Glass Liner 480°C (900°F)
Stainless Steel Sheath and Liner 650°C (1200°F)
Inconel or C276 Alloy Sheath and Liner 870°C (1600°F)
Inconel or C276 Alloy Sheath and Quartz Liner 870°C (1600°F)
Probe Heater:
For accurate results, the sample temperature should remain in
the range of 120oC ± 5oC (248oF ± 9oF) as it travels through the
probe.
Important: Exposure to elevated temperatures can damage the
insulation and shorten the life of the heater. The maximum
recommended stack exposure temperature for Probe Heaters is
260oC (500oF). Partial probe heaters are recommended for
temperature above 500ºF.
Apex Instruments Product Highlight
With accurate sampling in mind, Apex
Instruments Probe Heaters feature a
rigid tube heater with coiled heating
element, electrical thermal insulation
with integrated thermocouple, and a
power cord sealed in silicone-
impregnated glass insulation.
Also, our mandrel-type heater design
allows you to replace the liner as
needed without removing the heating
element. Standard heaters are
configured for 120VAC operation;
240VAC configuration is available.
16
How to Connect the Probe Assembly to the Modular Sample Case:
The Probe Assembly connects to the Modular Sample Case with the following steps:
1. Mount the probe sheath to the Modular Sample Case using a probe clamp that is attached to the probe
holder.
2. Look for the thermocouple male connector extending from the probe assembly and connect it to the
female thermocouple connector of the Umbilical Cable.
3. Connect the electrical plug to the electrical receptacle on the Modular Sample Case Hot Box.
4. Insert the outlet ball of the Probe Liner through the entry hole of the Filter Oven (Hot Box)
compartment until the back of the sheath is even with the inside of the sample case.
5. Connect the pitot tube quick-connect lines, probe heater thermocouple, stack thermocouple and Orsat
gas sample line to the Source Sampler Console via the Umbilical Cable.
17
4. Modular Sample Case
The Modular Sample Case is used for support, protection and environmental control of the glassware in the
sampling train. The Modular Sample Case consists of an insulated heated filter compartment (Hot Box) and
insulated impinger case (Cold Box).
Figure 1-6 illustrates the major components and accessory connections on the Modular Sample Case.
Figure 1-6: Modular Sample Case Components and Accessories
The impinger case (cold box) holds the sampling train
impingers in an ice bath so that the stack gas sample is cooled
as it passes through the impingers to condense the water
vapor. This process allows you to measure stack gas moisture
volume, then use that reading to calculate stack gas density.
Figure 1–7: From left to right, SB-3, SB-4, SB-4SD, SB-
4SDM2, and SB-5 Impinger Boxes
Tips from a Stack Tester
Obtain multiple Impinger
Cases and sets of impingers
for rapid turnaround time
between test runs.
Some companies offer
impinger cases for a variety of
different number of impingers.
Filter Oven
Impinger
Case
Riser
Handle with Safety Clip
Door Latch (both sides)
Umbilical Adapter Clamp
Impinger Case Drain
Probe Power Receptacle
Amphenol Connector
Oven Thermocouple Connector
Hinged Probe
Clamp
Aux. Power
34.3cm
24.1cm
31.8cm
18
5. Umbilical Cable with Umbilical Adapter
The Umbilical Cable connects the Modular Sample case and Probe Assembly to the Source Sampler Console.
The Umbilical Cable typically contains the gas sample and pitot lines, as well as thermocouple and power
lines.
Below is an example of the configuration of the umbilical connections (using the Apex Instruments product as
an example):
● The primary gas sample line (blue, 3/8 in. i.d./12.7 mm (5/8 in. o.d.)) has a male quick-connect on the
outlet, at the opposite end, a 12.7 mm (5/8 in.) female quick-connect on the inlet.
● The two (2) pitot lines, (black and white, 6.35 mm (1/4 in.)), have female quick-connects to the Probe
Assembly and 6.35 mm (1/4 in.) male quick-connects to the Source Sampler Console. There is an
additional gas sample line for Orsat analysis (yellow, 6.35 mm (1/4 in.)), which also can be used as a
spare pitot line.
● Multiple thermocouple extension cables for Type-K thermocouples, which terminate with durable full-
size connectors. The connectors have different diameter round pins to ensure proper polarity, and will not
fully connect if reversed. Each thermocouple extension wire in the Umbilical Cable is labeled and color-
coded for temperature measurement of Stack, Probe, Oven (Hot Box), Exit (Cold Box), and Auxiliary
(spare).
● The AC power cable (for Filter Oven and Probe Assembly heaters) terminates with a circular, military-
style connector on each end.
● The Umbilical Adapter connects the outlet of the last impinger to the Umbilical Cable and contains the
exit thermocouple. This adapter serves to relieve strain between the Umbilical Cable and the glassware
train.
● The body of the circular connector is grounded. A line-up guide is placed on each connector’s end, and
the retainer threads should be engaged for good contact. Figure 1-8 illustrates the circular connector with
pins labeled.
● The Umbilical Cable is covered with a woven nylon mesh sheath to restrain the cable and reduce friction
when moving the cable.
Figure 1-8: Circular Connector and Electrical Pin Designations
19
How to Construct a Glassware Sample Train:
The sample glassware train contains the filter holder for collection of particulate matter, glass impingers for
absorption of entrained moisture, and connecting glassware pieces.
Figure 1-9 below illustrates the glassware of the US EPA Method 5 sampling train.
The order in which a typical US EPA Method 5 glassware train is constructed is as follows:
1. Cyclone Bypass (GN-1), Optional: Cyclone (GN-2) and Cyclone Flask (GN-3)
2. 3 in. Glass Filter Assembly (GNFA-3). Assembly consists of the Filter Inlet (GN-3S), Teflon Filter Disk
or “Frit” (GA-3T), Filter Outlet (GN-3B), Filter Clamp (GA-3CA), and Glass Fiber Filter (GF-3 Series).
3. Double “L” Adapter (GN-8), or alternate GN-8-18K with thermocouple assembly
4. 1st Impinger Modified Greenburg-Smith (GN-9A)
5. U-Tube (GN-11)
6. 2nd Impinger Greenburg-Smith with Orifice (GN-9AO)
7. U-Tube (GN-11)
8. 3rd Impinger Modified Greenburg-Smith (GN-9A)
9. U-Tube (GN-11)
10. 4th Impinger Modified Greenburg-Smith (GN-9A )
Figure 1-9: Glassware Sampling Train Schematic
20
Chapter 2
Operating Procedures There are several steps to complete before testing for
particulate matter, which include:
1. Set up and inspection of source sampling system,
review of calibration records
2. Test design
3. Site preparation
4. Sampling equipment calibrations (see Chapter 3)
5. Assembling sampling equipment and accessories,
reagents, sample recovery equipment, and sample storage containers
6. Preliminary measurements of stack dimensions, gas velocity, dry molecular weight, and moisture.
1. Set-up and Check of Source Sampling System
When unpacking your sampling system for the first time, check each part for damage and ensure your shipment
is complete by checking items off the packing list.
If you purchased your product from Apex Instruments, please call us immediately at 800-882-3214 or email
us at [email protected] to seek help with any damaged or missing products.
A. Initial Set-up Procedure
These instructions are for a “dry run” set-up of the complete US EPA Method 5 sampling train.
Important: Do not load a glass fiber filter into the filter assembly or charge liquids and silica gel in the
impingers. The objective is just to set-up the equipment to verify that everything works. Start with these steps:
1. Remove all items from packaging and place in an open area.
2. Slide the Impinger Case (Cold Box) onto the Modular Sample Case’s heated filter oven (Hot Box),
using the steel slide guides. Check the fit and height of the Sample Case and Umbilical Adapter.
Adjust the steel slides to achieve the desired fit. Engage the spring latch that locks the Impinger Case
into place.
3. Inspect the Probe Liner and Probe Assembly. Wipe clean the quick-connects on the Probe Assembly.
Tips from a Stack Tester
A drop of penetrating oil
helps keep the quick-
connects in good working
condition. Inspect the pitot
tube openings for damage
or misalignment, and
replace or repair them if
necessary.
21
4. Slide the Probe Liner into the probe sheath. The liner’s plain end (no ball joint) should come out
approximately 1.27 cm (1/2 in.) at the pitot tube end of the Probe Assembly.
5. Insert the Probe Assembly into the probe clamp that is attached to the Filter Oven and tighten. Then,
carefully insert the outlet ball of the Probe Liner through the hole into the Hot Box. The back of the
sheath should be even with the inside of the Hot Box. Next, plug the Probe Heater electrical plug into
the probe receptacle on the Hot Box.
6. To install a nozzle on the Probe Assembly, consult Figure 2-1. Slide the ferrule system onto the plain
exposed end of the Probe Liner. Substitute high-temperature braided glass cord packing for the
ferrule when stack temperatures are greater than 260°C (500°F) or use liner with integrated nozzle.
Apex Instruments’ Probe Assembly Spare Parts Kit (the bag taped to probe sheath) contains fittings for
two (2) different ferrule installation options: 1) Stainless Steel Single Ferrule and 2) Backer Ring with O-
Ring. The recommended configurations for different liner options are detailed below:
• Stainless Steel Liner: Stainless Steel Single Ferrule or Backer Ring with O-Ring
• Glass Liner: Backer Ring with O-Ring, or PTFE Single Ferrule (Optional), or Glass-filled PTFE
Single Ferrule (Optional).
Figure 2-1: Installation of Stainless Steel and Glass Probe Nozzle Connectors
7. Thread the 15.875 mm (5/8 in.) union onto the nut welded to the probe sheath. This is a compression
fitting that is tapered to seal the ferrule system inserted on the Probe Liner.
Important: Tighten the fitting until the liner has a leak-tight seal, but DO NOT OVERTIGHTEN.
8. Connect the glassware sampling train completely in the Filter Oven (Hot Box) and Impinger Case
(Cold Box) (see Figure 1-9 and the related “How to Construct a Glassware Sample Train” at the end
of Chapter 1). Tighten all joints using the Ball Joint Clamps. The final connection is the Umbilical
Adapter, which slides into the clamp on the outside of the Impinger Case. Again, do not load the
Filter Assembly with a filter, and do not fill the impingers because this is a “dry run” set-up.
9. To connect the Umbilical Cable to the Modular Sample Case, first connect the Umbilical Cable
circular connector plug to the receptacle on the side of the Filter Oven (see Figure 1-6). Next, connect
the labeled Umbilical Cable thermocouple plugs into the receptacles on the Filter Oven, Probe
Stainless Steel Nozzle Glass Nozzle
22
Assembly, and Umbilical Adapter. Then, insert the Umbilical Cable sample line female quick-
connect into the Umbilical Adapter male quick-connect. Finally, insert the Umbilical Cable female
pitot line quick-connects into the Probe Assembly male quick-connects.
10. To connect the Umbilical Cable to the Source Sampler Console, first connect the Umbilical Cable
circular connector plug to the receptacle on the front panel of the Source Sampler Console. Then,
connect the labeled Umbilical Cable thermocouple plugs into the receptacles on the Source Sampler
Console front panel.
Next, insert the Umbilical Cable sample line male quick-connect into the Source Sampler Console
female quick-connect. Finally, insert the Umbilical Cable pitot line male quick-connects into the
Source Sampler Console female quick-connects (labeled + and −). The pitot lines are colored to
differentiate the positive and negative lines and ensure the connections are consistent between the
pitot tube and Source Sampler Console.
11. To connect the Vacuum Pump Assembly to the Source Sampler Console, first wipe the quick-
connects clean, then connect the pressure and vacuum hoses on the Vacuum Pump Assembly to the
pump connections located on the lower left of the Source Sampler Console front panel. Then, connect
the power cord of the Vacuum Pump Assembly to the receptacle labeled PUMP on the Source
Sampler Console.
12. Plug the Source Sampler Console into an appropriate electrical power source.
B. Initial Sampling System Leak Check
Remember to follow the set-up procedure detailed in the previous section before starting a system check
procedure. The system leak check described below is a “dry” run:
1. Close the Coarse Valve on the Source Sampler Console.
2. Seal the inlet to nozzle.
3. Turn on the Vacuum Pump with the PUMP POWER ON switch.
4. Slowly open the Coarse Valve and increase (which means turn clockwise until close) the Fine
Increase Valve.
5. The pump vacuum, as indicated on the Vacuum Gauge, should read a system vacuum within 10 kPa
(3 in. Hg) of the barometric pressure. Example: If the barometric pressure is 100 kPa (30 in. Hg),
then the Vacuum Gauge should read at least 92 kPa (27 in. Hg).
6. Wait a few seconds for the pressure to stabilize. When the Orifice Tube pressure differential (ΔH) has
returned to the zero mark, measure the leak rate for one minute, as indicated on the dry gas meter
display. The observed leak rate should be less than 0.56 liters per minute (lpm) (0.02 cubic feet per
minute (cfm)). If the leak rate is greater, check the tightness of all connections in the sampling train
and repeat.
23
2. Test Design
Before testing, define the test parameters by answering the following:
● Why is the test being conducted?
● Who will use the data?
● Which stacks or emission points are being tested?
● What process data is being collected and correlated with test results?
● Where are the sample ports located and what type of access is available?
● When is the test scheduled, and what are the deadlines for reporting?
● What is the specific method or procedure to follow?
● How many test runs or process conditions will be tested?
3. Site Preparation
Preparing the site so that sampling equipment can be positioned correctly is frequently the most difficult part
of the sampling process. When the sample ports do not have a platform or catwalk, then scaffolding must be
erected to reach the sampling site. At many sites, operators must use their ingenuity to get the sampling
equipment to the sampling location.
When selecting the site for sample ports, keep in mind that the distance from the probe to the bottom of the
sample case is about 33 cm (13.5 in.). This means that when traversing the stack, the sampling equipment
needs 33 cm of clearance below the port level to avoid bumping into guardrails or other structures.
To calculate the clearance needed along the sample port plane, start with the effective probe length (which is
stack diameter plus port nipple length) and add at least 91 cm (36 in.) to accommodate the length of the sample
case (Filter Oven, Impinger Case, and probe clamp).
Figure 2-2 on the next page illustrates the clearance zones required.
24
Figure 2-2: Clearance Zones at Stack for Isokinetic Sampling Train
25
Figure 2-3: Schematic of Non-Rigid Isokinetic Sampling Train
Apex Instruments Product Highlight
If you can’t find a solution for sampling train clearance problems,
Apex Instruments can provide one. We offer a Non-Rigid Method 5
sampling train with a separate and/or miniature heated Filter Box (SB-
2M), which allows you to put the Cold Box on the sampling platform,
where it is connected by the sample line and Umbilical Adapter (GA-
104).
Figure 2-3 on the next page illustrates the Non-Rigid Isokinetic
Sampling Train. The midget hot box decreases the clearance needed
between the monorail and guardrail of the stack.
26
Did you know? Although the Isokinetic Source Sampling System is
designed to fit into a 6.35 cm (2.5 in.) sample port, a larger port hole
measuring 7.6 cm (3 in.) or greater allows you to insert and remove the
probe more easily, without damaging the nozzle or picking up deposited
dust.
Figure 2-4: Schematic of Compact Isokinetic Sampling Train
Mount the Hot and Cold Boxes
There are two ways to mount the isokinetic sampling system (which includes the Filter Oven and Impinger
Case) on a stack:
Apex Instruments Product Highlight
A second solution for clearance problems is our Compact
Method 5 sampling train with a Heated Filter Assembly
(SFA-82H) and Power Box Adapter (UA-3J).
Figure 2-4 below illustrates the Compact Method 5 option.
The smaller heated filter assembly allows for greater
flexibility in small sampling areas.
27
1. Assemble a monorail system with lubricated roller hook above each sample port, or
2. Construct a wooden platform slide apparatus (where feasible).
Figure 2-5 illustrates an isokinetic sampling system mounted on a monorail system above a sample port with
a tee bracket system. Another way to do a monorail mounting is when there is an angle iron, with a hole or an
eyehook, welded to the stack.
Figure 2-5: Illustration of Monorail System for Sampling Train
Figure 2-6: Illustration of Apex Instruments
Monomount Monorail System
Apex Instruments Product Highlight
When no mounting support for a monorail
system exists, you can easily construct one
using the Apex Instruments Monomount
(P501) around the stack, as shown in Figure
2-6 on the next page.
28
Illustrated below is a complete stack set-up in two different configurations: Figure 2-7 shows the Hot
Box/Cold Box together (SB-1) and Figure 2-8 shows the Filter Oven and Impinger Case separated (SB-2M
and SB-3).
Figure 2-7: Stack Platform Set-up with Modular Sample Case on Monorail
29
Figure 2-8: Stack Set-up with Hot Box on Monorail Separated from Cold Box
Assemble Sampling Equipment and Reagents
Remember to use checklists when assembling the sampling equipment, reagents and auxiliary supplies for a
test. See Appendix A for checklists of recommended equipment, spare parts and reagents for isokinetic
sampling. Keep in mind that you may not need the entire list at the test site. Also, refer to Section 3 of US EPA
Method 5 for the list of reagents required to perform an isokinetic particulate test.
Obtain Preliminary Measurements of Gas Velocity, Molecular Weight and Moisture
Before attempting to calculate the parameters needed for isokinetic sampling – such as probe nozzle size,
ΔH/Δp ratio (K factor), gas sample volume, etc. – you first must determine several preliminary values
described in Table 2-1 on the next page.
Table 2-1: Preliminary Measurements for Isokinetic Sampling
No. Symbol Value Needed Obtain from
30
1. Δpavg Average stack gas velocity pressure head 1. Before the sample run (best), or 2. A previous test (often erroneous)
2. Ps Stack gas pressure 1. Before the sample run (best), or 2. A previous test (very small error)
3. Pm Dry gas meter pressure
Same as barometric pressure
4. Bws Stack gas moisture fraction 1. Before the sample run (best), or 2. A previous test (often erroneous)
5. Ts Average stack gas temperature 1. Before the sample run (best), or 2. A previous test (often erroneous)
6. Tm Average dry gas meter temperature Meter temperature rises above ambient
because of pump heat and is typically
estimated at 14°C (25°F) above ambient
7. Md Stack gas molecular weight 1. Before the sample run (best), or 2. A previous test (very small error)
8. ΔH@ Orifice meter calibration factor Determined previously from laboratory
calibration
Tips from a Stack Tester
Obtain most of the
preliminary values just
before the sample run
rather than using old data.
Relying on previous tests
for values such as average
stack gas velocity, stack
gas moisture, and average
stack gas temperature can
lead to erroneous results.
31
Method 1
Determining Sample and Velocity Traverse Points
Method 1 is the first step toward collection of a representative sample to measure a stack’s particulate
concentration and mass emission rate. Method 1 is applicable to gas streams flowing in ducts, stacks and
flues. Since the velocity and particle concentration in the stack are not uniform, you must traverse the cross-
section to obtain a representative sample.
Keep in mind: This method cannot be used when:
1. The flow is cyclonic or swirling and is skewed to one side.
2. A stack is smaller than 0.30 meter (12 in.) in diameter, or 0.071 m² (113 in.²) in cross-sectional area. For
stacks and ducts measuring less than 12 in. in diameter, see Method 1A immediately following this section.
Did you know? Methods 1 through 4 are like building blocks, providing the
preliminary values needed to complete Method 5 sampling. Thus, when you perform
a sampling run using Method 5, you will need to know Methods 1 through 4
procedures to collect the data needed for Method 5 sampling and calculations.
Through the rest of Chapter 2, we have provided concise and easy-to-use information
for performing US EPA Methods 1 through 5.
32
The number of required traverse points depends on the shape - or straightness - of the stack or duct. Straighter
lengths of stack or duct produce flow streamlines that are more uniform, so fewer traverse points are needed
to obtain a representative sample. Conversely, if your sampling site is close to bends in the stack or other flow
disturbances, you will need to use more traverse points to obtain a representative sample.
Method 1 describes procedures to:
● Select appropriate sampling locations on the stack (if sample ports do not already exist).
● Calculate the number of traverse points for velocity and particulate sampling.
● Calculate the location of the traverse points.
We can identify appropriate sampling sites by measuring their distance from any type of flow disturbance in
the stack. Disturbances can be bends, transitions, expansions, contractions, stack exit to atmosphere, flames,
or the presence of internal installations such as valves or baffles.
To calculate distance between the sampling site and flow disturbances, first we measure the internal stack
diameter. Then, we use that length to determine how many “diameters” are in between the sampling site and
the flow disturbance.
Figure 2-9 on the next page depicts how stack diameters are used to measure distance from a flow disturbance
such as a bend. The example on the left shows an acceptable sampling site, which is eight (8) diameters
downstream from a bend and two (2) diameters upstream from the stack exit. The example on the right is not
an acceptable sampling site because it is too close to a flow disturbance (the bend in the stack).
33
Figure 2-9: Visualizing Stack Diameters from Flow Disturbances
Calculate Traverse Points
Calculate the minimum number of traverse
points needed with the following steps:
1. Measure the stack diameter to within
0.3175 cm (1/8 in.).
a. Insert a long rod or pitot tube
into the duct until it touches the
opposite wall.
b. Mark the point on the rod where
it meets the outside of the port
nipple.
c. Remove the rod, measure and
record this length to the far wall
(Lfw.).
d. With a tape measure (or rod if
the stack is hot), measure the
distance from the outside of the
Tips from a Stack Tester
Measure the stack diameter from each
sampling port and use the average, since not
all circular stacks are round and not all
rectangular stacks are perfectly rectangular.
By measuring through each port, you can
often find in-stack obstructions and take
steps to avoid erroneous measurements.
If possible, shine a flashlight across the stack
to look for obstructions or irregularities.
If possible, using a gloved hand, reach into
the sampling port and check that the port
was installed flush with the stack wall (and
that it does not extend into the flow.)
34
port nipple to the near wall and record this length (Lnw).
e. Calculate the diameter of the duct from this port as D = Lfw - Lnw.
2. Repeat for the other port(s) and then average the diameter (D) values.
3. Then, measure the distance from the sample port cross-sectional (horizontal) plane to the nearest
downstream disturbance (designated Distance A).
4. Next, measure the distance from the sample port cross-sectional plane to the nearest upstream
disturbance (designated Distance B).
5. Calculate the number of duct diameters to the disturbances by dividing Distance A (to downstream
disturbance) by the average diameter (D). Do the same for Distance B (to upstream disturbance).
6. Using Figure 2-10 (for particulate traverses) or 2-10b (for velocity traverses), determine where Distance
A (top) intersects the solid traverse points line running through the middle of the graph. Then, determine
where Distance B meets the traverse points line, and select the higher of the two numbers as the
minimum number of traverse points needed for sampling.
Example: The dotted lines in Figure 2-10 represent a Distance A measurement of 1.7 duct diameters and a
Distance B measurement of 7.25 duct diameters. Looking at where the dotted lines intersect the solid
traverse points line, Distance A requires 16 traverse points, while Distance B requires 12 traverse points.
Always choose the higher of the two numbers. In this example, the sampling site requires 16 total traverse
points. The 16 points are arranged in two lines of eight points each which are 90° apart, forming a cross
shape.
Figure 2-10: Example of How to Determine Number of Traverse Points (Particulates)
35
Figure 2-10b: Example of How to Determine Number of Traverse Points (Non-Particulates)
Identify Minimum Number of Traverse Points
● For circular stacks with diameters greater than 60 cm (24 in.), the minimum number of traverse points
required is twelve (12), or six (6) in each of two directions 90° apart (see Figure 2-11). This applies
when disturbances are eight (8) or more duct diameters upstream and two (2) or more downstream.
● For circular stacks with diameters between 30 and 60 cm (12 and 24 in.), the minimum number of
traverse points required is eight (8), or four (4) in each of two directions 90° apart.
● For stacks less than 30 cm (12 in.) in diameter, refer to Method 1A for calculating traverse points.
● The minimum number of traverse points required for rectangular stacks is nine, or 3 x 3.
For rectangular stacks or ducts, first calculate an equivalent diameter using the following equation:
where De = equivalent diameter of rectangular stack
L = length of stack
W = width of stack
36
Determine the Location of Traverse Points
Circular Stacks
After determining the number of traverse points, you must calculate the location of each traverse point. The
method for locating the traverse points for circular stacks is as follows:
1. Divide the number of traverse points by four (4). The resulting number will give you the number of
concentric circles of equal area to use in your sample point matrix. In the example illustrated in Figure
2-11, twelve (12) traverse points divided by four (4) equals three (3).
2. Bisect the circles twice, cutting them into quarters, as shown below.
3. Place the sample points in the centroid (center of mass) of each equal area, as shown in Figure 2-11.
Figure 2-11: Traverse Points Located in Centroids for Circular Stack
Pinpoint and Mark Traverse Points
Follow this procedure to locate each traverse point across the
diameter of a circular stack and mark the corresponding point on
the probe assembly or pitot tube:
1. On a Method 1 field data sheet (which can be computer or
calculator generated), multiply the stack diameter by the
percentage taken from the appropriate column of Table 2-
2. For example, the 4th traverse point along a diameter
with 6 points is equivalent to 70.4% of the stack diameter
(D x .704).
Tips from a Stack
Tester
You may combine two
successive points to
form a single adjusted
point, which must be
sampled twice.
37
2. Add the port nipple length to the value calculated in step 1 for each traverse point.
3. Round each value to the nearest 1/8th (0.125) of an inch for each point (English units only).
4. For stacks greater than 60 cm (24 in.) in diameter, relocate any traverse points closer than 2.5 cm
(1.00 in.) to the stack wall to 2.5 cm and label them as “adjusted” points.
5. For stacks less than 60 cm (24 in.) in diameter, use an adjusted distance of 1.3 cm (0.5 in) to relocate
any points away from the stack wall.
6. Measure each traverse point location from the tip of the pitot tube and mark the distance with heat-
resistant fiber tape or “Wite-Out” correction fluid, as illustrated in Figure 2-13.
Table 2-2 Location of Traverse Points in Circular Stacks
(Percent of stack diameter from inside wall of traverse point)
Traverse point number on a diameter Number of traverse points on a diameter
4 6 8 10 12 4 93.3 70.4 32.3 22.6 17.7 5 85.4 67.7 34.2 25.0
6 95.6 80.6 65.8 35.6
7 89.5 77.4 64.4
8 96.8 85.4 75.0
9 91.8 82.3
10 97.4 88.2
11 93.3
12 97.9
38
Tips from a Stack Tester
After calculating the traverse point locations (before
adding sample port nipple length), you can check your
work quickly by noticing if the first and last traverse point
distances added together equal the stack diameter; then if
the second and next to last equal the same; then if the
third and third from last equal the same; and so on.
For instance, with a stack diameter of 60 cm and 12
traverse points, the 4th point is 10.62 cm (60 cm x 0.177)
from the port and the 9th point is 49.38 cm (60cm x
0.823) from the port. 10.62 cm + 49.38 cm = 60 cm.
39
Figure 2-13: Illustration of Marking Traverse Points on Probe Assembly
Rectangular Stacks
For rectangular stacks, the centroids for placing the traverse points are much easier to determine, as shown in
Figure 2-12.
Figure 2-12: Traverse Points Located in Centroids for Rectangular Stack
Table 2-3: Cross Section Layout for Rectangular Stacks
Number of Traverse Points Matrix Layout 9 3 x 3 12 4 x 3 16 4 x 4 20 5 x 4 25 5 x 5 30 6 x 5 36 6 x 6 42 7 x 6 49 7 x 7
40
Method 1A
Sample and Velocity Traverses,
Small Stacks or Ducts
Method 1A is the same as Method 1, except for the special provisions that apply to small circular stacks or
ducts where the diameter is between 4 and 12 inches (10.2 cm (4 in.) ≤ D ≤ 30.5 cm (12 in.)), or for small
rectangular ducts where the area is between 12.57 in.2 and 113 in.2 (81.1 cm2 (12.57 in.2) ≤ A ≤ 729 cm2 (113
in. 2)).
Important: You must use a standard type pitot tube for the velocity measurements. Do not attach the tube to
the sampling probe.
The procedure for determining sampling location, traverse points, and flow rate (preliminary or otherwise) in
a small duct is as follows:
1. Use Method 1 to locate traverse points for each sampling site and choose the highest of the four
numbers for the total traverse point number.
2. For measurements of particulate matter (PM) with a steady flow, or velocity with either a steady or
unsteady flow, select one sampling location and use the same criterion as described in Method 1.
3. For PM with a steady flow, conduct velocity traverses in the same port before and after PM sampling
to demonstrate steady state conditions, i.e., within ± 10% (vf/vi ≤ 1.10).
4. For PM with an unsteady flow, monitor velocity and sample PM at two separate locations
simultaneously. The velocity port should be downstream of the sampling port. See the location of the
two ports labeled in Figure 2-14 on the next page.
Did you know? In small diameter stacks or ducts, the conventional Method 5 stack
assembly (which consists of a Type-S pitot tube attached to a sampling probe
equipped with a nozzle and thermocouple) blocks a significant portion of the duct’s
cross-section, resulting in inaccurate measurements. Therefore, for particulate
matter sampling in small ducts, measure the gas velocity either:
➢ Downstream of the sampling nozzle (for unsteady flow conditions), or
➢ In the same sample port alternately before and after sampling (for steady
flow conditions).
41
Figure 2-14: Set-up of EPA Method 1A Small Duct Sampling Locations
42
Method 2
Stack Gas Velocity and Volumetric Flow Rate
Method 2 is used to measure the average velocity and volumetric flow rate of the stack gas stream. To
determine the average gas velocity in the stack, you must measure the gas density and the average velocity
head with a Type-S (Stausscheibe or reverse-type) pitot tube. Note: Have a thorough knowledge of at least
Method 1 before proceeding, as some of the steps reference Method 1 procedures.
Method 2 is used to:
➢ Determine the nozzle size and length of the sampling run before a particulate stack test series (also
known as a preliminary velocity determination).
➢ Ensure that the particulate sample is extracted from the stack at isokinetic conditions during each
stack test run.
The equation for average gas velocity in a stack or duct is:
Where vs = Average stack gas velocity, m/sec (ft/sec)
Kp = Constant, 34.97 for metric system (85.49 for English system)
Cp = Pitot tube coefficient, dimensionless
(√Δp)avg = Average of the square roots of each stack gas velocity head, mm H2O (in. H2O)
Ts = Absolute average stack gas temperature, °K (°R)
Ps = Absolute stack gas pressure (Pbar + Pg/13.6), mm Hg (in. Hg)
Did you know? Do not use Method 2 with measurement sites that are less than
eight stack diameters downstream or two stack diameters upstream from a flow
disturbance. Method 2 also cannot be used for direct measurement in cyclonic or
swirling gas streams (see section 11.4 of Method 1 to determine these conditions).
When faced with cyclonic or swirling gas streams, you must use alternative
procedures such as installing straightening vanes, calculating the total volumetric
flow rate stoichiometrically, or moving to another measurement site where the
flow is acceptable.
43
Pbar = Barometric pressure at measurement site, mm Hg (in. Hg)
Pg = Stack static pressure, mm H2O (in. H2O)
Ms = Molecular weight of stack on wet basis (Md (1 – Bws) + 18.0 Bws), g/g-mole
(lb/lb-mole)
Md = Molecular weight of stack on dry basis, g/g-mole (lb/lb-mole)
Bws = Water vapor in the gas stream (from Method 4 (reference method) or Method
5), proportion by volume.
Obtain Stack Gas Molecular Weight and Moisture
To calculate the average stack gas velocity (Vs), you must first obtain values for the molecular weight and
moisture (refer to Method 3 and Method 4 sections). The stack gas molecular weight dry basis (Md) is corrected
to the wet basis (Ms) using the moisture fraction (Bws) with the equation:
Figure 2-15 illustrates the relationship of Methods 1, 3 and 4 to Method 2.
Figure 2-15: Determination of Preliminary Velocity
Method 3 Stack Gas Molecular Weight Options:
• Sample with Orsat analysis
• Sample with Fyrite analysis
• Assign 29.0 if air
• Assign 30.0 if combustion
Method 1 Selection of Traverse Points
Method 2 Stack Gas Velocity
Method 4 Stack Gas Moisture Options:
• Reference Method
• Approx Method (Midgets)
• Drying Tubes
• Wet Bulb-Dry Bulb
• Psychrometric chart
• Previous experience
44
Using the Pitot Tube
Use a pitot tube connected to an inclined manometer to make velocity measurements in a duct. Alternatives to
the inclined manometer are a magnehelic pressure gauge or an electronic manometer, but you must calibrate
each of these devices periodically against an oil-filled inclined manometer (see Calibration in Chapter 3).
The S-type pitot tube has a fixed coefficient of 0.84 if it is manufactured and maintained to meet the geometric
specifications of Method 2. You may also use a standard or P-type (Prandl) pitot tube with a coefficient of
0.99 for these measurements.
Insert the S-type pitot tube into the stack with one leg (hole opening) pointing into the direction of gas flow,
as shown in Figure 2-16. The leg pointing into the flow stream measures impact pressure (Pi) of the gas stream,
while the opposite leg (pointing away from the flow) measures wake pressure (Pw).
The velocity pressure (Δp) is the difference between the impact and wake pressures:
Figure 2-16: Apparatus for Preliminary Velocity Measurement
45
Determine Flow Rate
The procedure for determining flow rate (preliminary or other) in a stack gas stream is as follows:
1. Fill out the top section of a Velocity Traverse field data sheet.
2. Mark the pitot tube with the traverse points according to Method 1 (see “Pinpoint and Mark Traverse
Points” in the Method 1 section).
3. Assemble the apparatus for flow velocity measurement using one of these configurations:
a. Pitot tube with thermocouple, pitot and thermocouple extension lines, inclined manometer, and
temperature display device, or
b. Probe Assembly, Umbilical Cable, and inclined manometer on Meter Console.
4. Pitot Line Leak-Check: Conduct a pre-test leak-check of the
pitot and lines by blowing lightly into the positive (impact) side
of the pitot tube opening until at least 7.6 cm (3 in.) H2O
registers on the manometer; then, close off the impact opening.
The pressure should remain stable for at least 15 seconds. Do
the same, except suck lightly, for the negative (wake) side.
5. Level and zero the manometer. If using a separate manometer,
cup a hand or place a glove over the pitot opening to prevent
wind from affecting the zero adjustment. If using the Source
Sampler Console, use the Zero Manometer switch. Periodically
check that the manometer is zeroed and leveled between ports.
6. Insert the pitot tube into the stack to a marked traverse point
and seal off the port opening with a rag or towel to prevent
ambient effects. Starting with the farthest points, measure the
velocity head and temperature and record the values on the
field data sheet. Allow the temperature reading to stabilize
before recording it.
7. Move to each subsequent traverse point, reseal the port and
record the velocity head and temperature. Switch to the next port and repeat traverse sampling.
8. Conduct a post-test
leak-check (which is
mandatory to prove
that no leakage
occurred) as
described in Step 4
above, and record it
on field data sheet.
Tips from a Stack
Tester
If the pitot tube is dirty or
chemically contaminated,
attach a short piece of
flexible tubing to the pitot
leg for leak checking, and
pinch it closed to hold the
pressure.
Did you know? The S-type pitot tube is most often used in stack
testing because it is:
➢ Compact and attaches easily to a Method 5 probe assembly,
➢ Relatively easy to manufacture,
➢ Relatively insensitive to plugging in stack gas streams, and
➢ Relatively insensitive to yaw and pitch errors.
46
9. Measure the static pressure in the stack. One reading is adequate.
10. Determine the barometric pressure at the level of the sample port.
11. Calculate the average stack temperature from the traverse readings and record it.
12. Calculate the average square root of velocity head by taking the square root of each velocity head reading
and averaging the square roots (sum the square roots and then divide by the number of traverse points).
Then, record it on the field data sheet.
Important: Ensure that you are using the proper
manometer or pressure gauge for the range of Δp
(velocity head of stack gas) values you encounter. If a
more sensitive gauge is needed, swap it in and
remeasure the Δp and temperature readings at each
traverse point, using the above procedures.
Measure Static Pressure
You can measure static pressure in any of three ways:
➢ Using a static tap,
➢ Using a straight piece of tubing and
disconnecting one leg of the manometer, or
➢ Using the S-type pitot tube and disconnecting
one leg of the manometer.
Measure Static Pressure with an
S-Type Pitot
If you are using an S-type pitot to measure static
pressure, follow these steps:
1. Insert the S-type pitot tube into the middle of the
stack.
2. Rotate the pitot about 90° until you obtain a zero or
null reading on the manometer.
3. Holding the pitot in place, disconnect the positive
side from the manometer and read the oil deflection
on the manometer gauge. Record the static pressure
as negative.
4. If the oil travels past the zero mark, reconnect the
positive side and disconnect the negative side, then
read the oil deflection in the manometer. Record the
static pressure as positive.
Tips from a Stack Tester
The easiest way to measure static
pressure is to insert a piece of metal
tubing connected to a U-tube water-
filled manometer into the
approximate middle of the stack, with
the other end open to atmosphere.
If the manometer deflects toward the
stack, record this as negative static
pressure (less than barometric
pressure). If the manometer deflects
away from the stack, record this as
positive static pressure.
If you are using an inclined
manometer, then place the connection
to the tubing on the negative (right-
hand) side of the manometer to read a
negative static pressure. Switch it to
the positive (left-hand) side to read a
positive static pressure. The
procedure is identical when using a
stack static tap.
47
After recording the static pressure (Pg), you must convert the value from mm H2O to mm Hg (in. H2O to in.
Hg) prior to inputting it into the velocity equation as Ps (absolute stack gas pressure). The density of mercury
is 13.6 times that of water, so the conversion equation is:
where Ps = Absolute stack gas pressure, mm Hg (in. Hg)
Pbar = Barometric pressure at measurement site, mm Hg (in. Hg)
Pg = Stack static pressure, mm H2O (in. H2O)
Obtain Barometric Pressure Reading
Obtain a barometric pressure reading (Pbar) at the measurement site by using a calibrated on-site barometer, or
by contacting a nearby weather station (within 30 km) to get the uncorrected station pressure (weather stations
report barometric pressure corrected to sea level, so ask for the “uncorrected” pressure). You also will need to
know the station’s elevation above sea level.
Correct the station’s barometric pressure reading by subtracting 0.832 mm Hg for every 100 m that the weather
station is above sea level (0.1 in. Hg for every 100 ft.). To get valid results, you also must know the sampling
site’s elevation.
Calculate the sampling site barometric pressure (Pbar) as follows:
where Pr = Barometric pressure at site ground level or at weather station, mm Hg (in. Hg)
A = Elevation at ground level or at weather station, m (ft. above sea level)
B = Elevation of the sampling site, m (ft. above sea level)
Calculate Volumetric Flow Rate
After calculating the average stack gas velocity (Vs, see the beginning of the Method 2 section), you can find
the volumetric flow rate. Begin by determining the area (As) for a circular stack with this equation:
48
Where π = 3.14159
Ds = Diameter of a circular stack
The formula to find the area of a rectangular stack is:
Where L = Length of a rectangular stack
W = Width of a rectangular stack
Now, you can calculate the stack gas volumetric flow rate (actual, standard, and dry standard) using the
following equations:
Where Qa = Volumetric flow rate, actual, m3/min (acf/min)
Vs = Average stack gas velocity, m/sec (ft/sec)
As = Area of the stack
Qs = Volumetric flow rate, standard, sm3/min (scf/min)
Ks = A constant of 21.553 for metric units (1058.8 for English units), used to convert
time to minutes and P/T (pressure divided by temperature) to standard
conditions
Ts = Absolute average stack gas temperature, °K (°R)
Ps = Absolute stack gas pressure (Pbar + Pg/13.6), mm Hg (in. Hg)
Pbar = Barometric pressure at measurement site, mm Hg (in. Hg)
Pg = Stack static pressure, mm H2O (in. H2O)
Qsd = Volumetric flow rate, dry standard, dsmm3/min (dscf/min)
Bws = Water vapor in the gas stream (from Method 4 (reference method) or Method
5), proportion by volume.
49
Method 3
Gas Analysis for Dry Molecular Weight
Method 3 is used to measure the percent concentrations of carbon dioxide (CO2), oxygen (O2), and carbon
monoxide (CO) if greater than 0.2%. Nitrogen (N2) is calculated by difference. With this data, you can calculate
the stack gas dry molecular weight, or density, and then apply that data to the equation for stack gas velocity.
There are three options for determining dry molecular weight:
1. Sample and analyze,
2. Calculate O2 and CO2 concentrations stoichiometrically for combustion sources, or
3. Use a dry molecular weight value of 30.0 if burning fossil fuels (coal, oil, or natural gas).
From the gas composition data, you can calculate the amount of excess air for combustion sources. In
jurisdictions where particulate emissions are regulated on a concentration basis, such as mg/m3, use the gas
composition data to correct the concentration results to a reference diluent concentration, for example 7% O2
or 12% CO2. Note: Before beginning, you first must have a thorough knowledge of Method 1 procedures,
which are referenced in Method 3.
Options for Collecting Stack Gas Sample
Use one of three options to collect the stack gas sample:
1. Grab-sampling stack gas from a single traverse point with a one-way squeeze bulb and loading it
directly into the analyzer. You also can use this technique to measure gas composition at individual
traverse points to determine if stratification exists.
2. Integrated sampling from a single traverse point into a flexible leak-free bag. This technique
recommends collecting at least 30 liters (1.00 cu. ft.); however, you may collect smaller volumes if
desired. Constant rate sampling is used.
3. Integrated sampling from multiple traverse points in a flexible leak-free bag. Use this technique
when conducting a Method 5 particulate traverse and using the Orsat gas collection line built onto the
probe assembly. Sample volume and rate recommendations are the same.
Analyze gas samples using either an Orsat or Fyrite analyzer. Figure 2-17 on the next page depicts the options
for sample collection and analysis.
50
Figure 2-17: Method 3 Sampling and Analysis Options
Compare Orsat and Fyrite Analyzers
Both the Orsat Analyzer and Fyrite Analyzer are gas absorption analyzers that measure the reduction in liquid
volume when a gas sample is absorbed and mixed into a liquid solution. They differ in the following ways:
● The Fyrite Analyzer uses separate gas absorption bulbs for O2 and CO2, while the Orsat Analyzer
(Model VSC-33) contains all three absorption bubblers for O2, CO2, and CO in a single analyzer train.
● The Orsat provides a more accurate analysis of gas composition, and is required by Method 3B when
pollutant concentration corrections are made for regulatory purposes.
● The Orsat analyzer does not typically measure the CO concentration for two reasons:
○ First, the detection limit of the analyzer is 0.2% by volume (2,000 ppmv), which is well above
most modern combustion source CO concentrations.
○ Secondly, the molecular weight of CO is the same as N2 (28 g/g-mole). Thus, the balance of
gas can be applied to N2 without any change in calculation of molecular weight.
Figure 2-18 on the next page illustrates an Orsat Analyzer connected to a bag sample collection enclosure. For
a more detailed discussion of gas analysis using an Orsat Analyzer, please refer to Apex Instruments’
Sampling Options
Gas Analysis
Options Single-point
Grab Sampling
Single-Point Integrated
Sampling
Multi-Point Integrated Sampling
Orsat Analyzer
Fyrite Analyzer
Bag Sample
51
Combustion Gas (ORSAT) Analyzer, Model VSC-33, User’s Manual and Operating Instructions, or the
operating instructions provided with the Fyrite Analyzer.
Figure 2-18: Illustration of Orsat Analyzer and Gas Sample Bag Container
Determine Dry Molecular Weight
Calculate the dry molecular weight (Md) of stack gas with the following equation:
Where 0.44 = Molecular weight of CO2, divided by 100
%CO2 = Percent CO2 by volume, dry basis
0.32 = Molecular weight of O2, divided by 100
%O2 = Percent O2 by volume, dry basis
0.28 = Molecular weight of N2 or CO, divided by 100
%N2 = Percent N2 by volume, dry basis
%CO = Percent CO by volume, dry basis
52
Method 4
Moisture Content of Stack Gas
Method 4 is used to determine the moisture content of stack gas, which is needed to calculate emission data.
A gas sample is extracted at a constant rate from the source, moisture is removed from the sample stream,
and moisture content is determined either volumetrically or gravimetrically. Before using this method, you
should have a thorough knowledge of at least Methods 1, 5 and 6.
There are two separate procedures for determining moisture content in stack gases:
➢ The Reference Method, which gives accurate measurements of moisture needed to calculate emission
data, and
➢ The Approximation method, which gives a close estimate of percent moisture to aid in setting
isokinetic sampling rates before a pollutant emission sampling run.
The approximation method is only a suggested approach. There are acceptable alternatives for approximating
moisture content, for example:
● Wet bulb/dry bulb techniques (applicable to gas streams less than 100°C),
● Stoichiometric calculations (applicable to combustion sources),
● Condensation techniques,
● Drying tubes, and
● Previous experience testing at a stack.
Equipment Set-Up for the Reference Method
Select either of the following sampling trains when setting up equipment for the Reference Method:
➢ The Isokinetic Source Sampling System (Hot Box and Cold Box), equipped with Probe Assembly
without nozzle, and a filter bypass piece of glassware (GN-13) instead of a filter assembly (you may
use a filter if particulate levels are high), or
➢ The Basic Method 4 Test Kit, which includes a Cold Box, Sample Frame with Probe Clamp (SB-8),
and Umbilical Adapter with power connector (GA-103), as shown in Figure 2-19 on the next page.
With this set-up, you can use either a standard heated Probe Assembly or a heated CEM probe (without
a pitot tube).
53
Did you know? The Reference Method is almost always performed simultaneously
with a pollutant emission measurement run. You also can use the Reference Method
when you need to correct to a dry basis your continuous monitoring for pollutants
such as SO2, NOx or O2.
Tips from a Stack Tester
Although glass impingers are typically used as the
condenser section in Method 4 and other isokinetic
methods, you can replace them with a stainless steel
equivalent coil condenser (S-4CN), which results in a
rugged and reliable system without the fragility of the
traditional glass assembly.
54
Figure 2-19: Set-up of Cold Box with Sample Frame and Probe Clamp
Method 4 Reference Method
Use the following procedure for accurate measurements of moisture content:
Part 1: Preparation
1. Select the appropriate minimum number of traverse points and locate them according to Method 1:
a. Eight (8) traverse points for circular ducts less than 60 cm (24 in.) in diameter.
b. Nine (9) for rectangular ducts less than 60 cm (24 in.) in equivalent diameter.
c. Twelve (12) for all other cases.
2. Transfer about 100 ml of water into the first two impingers. Leave the third impinger empty. Weigh
each impinger to the nearest 0.5 g.
3. Transfer 200-300 g of silica gel into the fourth impinger. Weigh it to the nearest 0.5 g.
4. Select a total sampling time that allows you to collect a minimum total gas volume of 0.60 scm (21
scf) at a rate no greater than 0.021 m3/min (0.75 cfm). Perform moisture sampling simultaneously
with the pollutant emission rate test run (and for the same length of time).
5. If the gas stream is saturated or contains moisture droplets, attach a temperature sensor (± 1.3°C) to
the probe or check the saturation moisture at the measured stack temperature. See Step 4 below.
Part 2: Sampling
1. Assemble and set up the sampling train.
2. Turn on the probe heater and, if applicable, the filter heating system to temperatures of about 120°C
(248°F). Allow time for the temperatures to stabilize. Place crushed ice in the ice bath container
(Cold Box) around the impingers.
3. Optional: Leak-check the sampling train by disconnecting the probe from the first impinger or, if
applicable, from the filter holder. Plug the inlet to the first impinger (or filter holder) and pull a 380
mm (15 in.) Hg vacuum. It is not acceptable to have a leakage rate greater than 4% of the average
55
sampling rate, or 0.00057 m3/min (0.020 cfm),
whichever is less. If the leakage rate exceeds the
allowable rate, either reject the test results or correct the
sample volume as in section 12.3 of Method 5.
Following the leak check, reconnect the probe to the
sampling train.
4. Position the probe tip at the first traverse point. Sample
at a constant (± 10%) flow rate. Record data on a field
data sheet.
5. Traverse the cross-section, sampling at each traverse
point for an equal period of time.
6. Add more ice and, if necessary, salt to maintain a
temperature of less than 20°C (68°F) at the silica gel
impinger exit.
7. After the last traverse point of the cross-section, turn off
the sample pump, switch to the next sample port, and repeat steps 5 and 6 above.
8. After completing sampling, disconnect the probe from the first impinger (or from the filter holder).
9. Mandatory: Leak-check the sampling train, as required at the end of the run (see step 3 above).
Part 3: Sample Recovery
1. Disassemble the impinger glassware and weigh each impinger to the nearest 0.5 g. Record weight
data on a field data sheet.
2. Verify constant sampling rate.
3. Calculate the stack moisture percentage (refer to the stack gas moisture equations at the end of the
Method 4 section).
In the Case of Saturated or Moisture Droplet-Laden Gases:
1. Measure the stack gas temperature at each traverse point. Calculate the average stack gas temperature
by adding all of the readings and dividing by the number of traverse points.
2. Determine the saturation moisture content by either:
a. Using saturation vapor pressure tables or equations, or
b. Using a psychrometric chart and making appropriate corrections if stack pressure is different
from what is found on the chart.
3. Use the lower of these values or the value from Part 3 above.
Tips from a Stack Tester
Make sure to wipe off
moisture from the outside
of each impinger before
weighing it. Do not weigh
impingers with U-tubes
connected.
56
Method 4: Approximation Method
The Method 4 approximation method specifies use of midget impingers and a Source Sampler Console sized
for midget impinger trains, such as the one used for Method 6 sampling of SO2.
Use the following procedures to make approximate measurements of moisture content:
Midget Impinger Train
Part 1: Preparation
1. Transfer about 5ml of water into each impinger (2) and weigh each impinger to the nearest 0.5 g.
2. Assemble the sampling train.
3. Connect a pre-weighed drying tube to the back of the impinger train.
Part 2: Sampling
1. Assemble and set up the sampling train.
2. Turn on the probe heater and, if applicable, the filter heating system to temperatures of about 120°C
(248°F). Allow time for the temperatures to stabilize. Place crushed ice in the ice bath container (Cold
Box) around the impingers.
3. Optional: Leak-check the sampling train by disconnecting the probe from the first impinger or, if
applicable, from the filter holder. Plug the inlet to the first impinger (or filter holder) and pull a 380
mm (15 in.) Hg vacuum. It is not acceptable to have a leakage rate greater than 4% of the average
sampling rate, or 0.00057 m3/min (0.020 cfm), whichever is less. If the leakage rate exceeds the
allowable rate, either reject the test results or correct the sample volume as in section 12.3 of Method
5. Following the leak check, reconnect the probe to the sampling train.
4. Position the probe tip well into the stack. Sample at a constant (± 10%) flow rate of twenty-one (21)
lpm until the dry gas meter registers about 30 liters, or until visible liquid droplets carry over from the
first impinger to the second. Record initial and final data on a field data sheet.
5. Add more ice and, if necessary, salt to maintain a temperature of less than 20°C (68°F) at the silica gel
impinger exit.
6. Mandatory: Leak-check the sampling train as described in Step 3 above. After the leak-check,
reconnect the probe to the sampling train.
Part 3: Sample Recovery
Did you know? Many stack testers perform preliminary moisture measurements for
input into their isokinetic calculations nomograph by using a full-size sampling train
and collecting approximately 0.283 sm3 (10scf) of gas sample. These runs take about
15 to 20 minutes.
57
1. Disassemble the impinger glassware and weigh each impinger or drying tube to the nearest 0.5 g.
Record weight data on a field data sheet.
2. Verify constant sampling rate.
3. Calculate the stack gas moisture percentage (see the equations at the end of this section).
Large Impinger Train
Part 1: Preparation
1. Transfer about 100ml of water into the first two impingers. Leave the third impinger empty and
weigh each impinger to the nearest 0.5 g.
2. Transfer 200-300 g of silica gel to the fourth impinger and weigh to the nearest 0.5 g.
Part 2: Sampling
1. Assemble and set up the sampling train.
2. Turn on the probe heater and, if applicable, the filter heating system to temperatures of about 120°C
(248°F). Allow time for the temperatures to stabilize. Place crushed ice in the ice bath container
(Cold Box) around the impingers.
3. Optional: Leak-check the sampling train from the first impinger inlet or, if applicable, the filter
holder (see leak-check procedures described in the Midget Impinger Train section on the previous
page).
4. Position the probe tip well into the stack. Sample at a constant (± 10%) flow rate of less than twenty-
one (21) lpm (0.75 cfm) until the dry gas meter registers 0.283 m3 (10 cf). Record initial and final
data on a field data sheet.
5. Add more ice and, if necessary, salt to maintain a temperature of less than 20°C (68°F) at the silica
gel impinger exit.
6. Mandatory: Leak-check the sampling train (as detailed in Part 2, Step 3 on the previous page).
Part 3: Sample Recovery
1. Disassemble the impinger glassware and weigh each impinger or drying tube to the nearest 0.5 g.
Record weighing data on a field data sheet.
2. Verify constant sampling rate.
3. Calculate the stack gas moisture percentage (see equations next page).
58
Equations for Calculating Stack Gas Moisture Content
To calculate the stack gas moisture content (Bws), first use the following equations to compute the sample gas
volume (Vm(std)) and gas moisture volume (Vwc(std)):
Calculate sample gas volume:
where K3 = 0.3858 °K/mm Hg (metric units), or 17.64 °R/in. Hg (English Units)
Y = Dry gas meter calibration factor
Vm = Dry gas volume measured by dry gas meter, dcm (dcf)
Pbar = Barometric pressure at measurement site, mm Hg (in. Hg)
ΔH = Average orifice tube pressure during sampling, mm H2O (in. H2O)
Tm = Absolute temperature at dry gas meter, °K (°R)
Calculate gas moisture volume:
where K2 = 0.001335 m3/g (metric units), or 0.04715 ft3/g (English units)
Wf = Final weight of water collected, g
Wi = Initial weight of water collected, g
Calculate stack gas moisture content:
where Bws = Proportion of water vapor, by volume, in the gas stream
Vm(std) = Sample gas volume
59
Vwc(std) = Gas moisture volume
Method 5
Determination of Particulate Emissions
Method 5 involves withdrawing particulate matter (PM) isokinetically from the source and collecting it on a
temperature-controlled glass fiber filter. The PM mass is determined gravimetrically after the removal of
uncombined water. To perform Method 5, you must have a thorough understanding of Methods 1, 2 and 3.
To maintain an isokinetic sampling rate, you will need to calculate the appropriate probe nozzle size and the
optimal ratio of orifice tube pressure (ΔH) to stack gas velocity (Δp). This ratio is called K-factor.
Determine nozzle size and K-factor in one of the following ways:
➢ Calculate by hand or on a worksheet (see worksheets in Appendix D).
➢ Use a specially designed stack testing slide rule nomograph (M5A-1M or M5A-1), as shown in
Figure 2-21.
➢ Use a pre-programmed handheld calculator (M5A-C).
➢ Input figures into specialized spreadsheets for data collection and reduction (ISOCALC 2.0) using a
personal or laptop computer, as shown in Figure 2-21.
Figure 2-21: Stack Sampling Slide Rule and Laptop Computer with IsoCalc 2.2
Preliminary Data Needed For Isokinetic Sampling
The following preliminary information is needed before you can determine the nozzle size and calculate the
K-factor:
➢ Δpavg: Average stack gas velocity head. Measure this before the sample run, or take it from a
previous test.
➢ Bws: Stack gas moisture fraction, or percent (%H2O). Determine this from a preliminary run, previous
test, or calculate it (see Method 4).
60
➢ Md: Stack gas dry molecular weight. Use a value from a preliminary run, previous test, or estimate it
(see Method 3).
➢ Ps: Stack gas pressure. Measure this before the sample run, or use barometric pressure if the static
pressure of the stack is very low (such as when sample ports are near the stack exit).
➢ ΔH@: Source Sampler Console orifice calibration factor. This is determined from the laboratory
calibration and should be readily available on-site (see Calibrations).
➢ Tm: Meter temperature. Temperature at the meter rises about 14°C (25°F) above ambient temperature
due to heat from the vacuum pump. Measure the ambient temperature at the Source Sampler Console
site.
➢ Pm: Meter pressure. Same as barometric pressure.
Probe Nozzle Size Calculation
The equation most commonly used for calculating the probe nozzle size is:
where Dn = Nozzle diameter, mm (in.)
K5 = 0.6071 (metric units) or 0.03575 (English units)
Qm = Test meter volume flow rate reading, m3/min (ft3/min)
Pm = Test meter average static pressure, mm Hg (in. Hg)
Tm = Average DGM temperature, °K (°R)
Cp = Pitot tube calibration coefficient, dimensionless
Bws = Water vapor in gas stream (Method 4 or alternative), proportion by volume
Ts = Average stack gas temperature, °K (°R)
Ms = Molecular weight of stack gas, wet basis, g/g-mole (lb/lb-mole)
Ps = Absolute stack or duct pressure, mm Hg (in. Hg)
Δpavg = Average stack gas velocity head
61
K-Factor Calculations
After selecting the appropriate nozzle from the Nozzle Set (shown in
Figure 2-22), calculate the K-factor ratio used to maintain an
isokinetic sampling rate at each traverse point for the sampling test
run. K-factor refers to the ratio of ΔH/Δp such that ΔH = KΔp. Use
the following equation:
where ΔH = Average orifice tube pressure during
sampling, mm H2O (in. H2O)
Δp = Average stack gas velocity head
K6 = 0.0000804 (metric units) or 849.842 (English units)
Dn = Nozzle diameter, mm (in.)
ΔH@ = Source Sampler Console orifice calibration factor
Cp = Pitot tube calibration coefficient, dimensionless
Bws = Water vapor in gas stream (Method 4 or alternative), proportion by volume
Md = Molecular weight of stack gas, dry basis, g/g-mole (lb/lb-mole)
Tm = Average DGM temperature, °K (°R)
Ps = Absolute stack or duct pressure, mm Hg (in.
Hg)
Ms = Molecular weight of stack or duct gas, wet
basis, g/g-mole (lb/lb-mole)
Ts = Average stack gas temperature,
°K (°R)
Pm = Test meter average static
pressure, mm Hg (in. Hg)
Important: Check the total sampling time (number of traverse
points multiplied by minutes per point) as well as the final
Tips from a Stack Tester
You may need to
experiment with selecting
K-factors and/or nozzle
sizes that will yield an
acceptable sampling
volume and time.
Figure 2-22: Probe Nozzle Set
62
estimated gas sample volume (Vm(std)) against any applicable environmental regulations to see if you have
met acceptable minimum sampling times and volumes.
Method 5 Test Procedure
Part 1: Pre-Test Preparation (Before Traveling to Site)
1. Check filters visually against light for irregularities, flaws or pinhole leaks. Label the filters on the back
side near the edge using numbering machine ink.
2. Desiccate the filters at 20° ± 5.6°C and ambient pressure for more than 24 hr. Then weigh them at
intervals of greater than 6 hours to a constant weight (less than 0.5 mg change from previous weighing).
Record results to the nearest 0.1 mg. During each weighing, do not expose the filter to the laboratory
atmosphere for more than 2 minutes, or to a relative humidity of more than 50%.
3. Optional: If you are measuring condensable or back-half particulate matter, run analytical blanks of
the deionized/distilled water to eliminate a high blank on actual test samples.
4. Clean the Probe Liners and Probe Nozzles internally by brushing first with tap water, then
distilled/deionized water, followed by reagent-grade acetone. Rinse the Probe liner with acetone and
allow to air-dry. Inspect visually for cleanliness and repeat the procedure if necessary. Cover the Probe
Liner openings to avoid contamination. Keep nozzles in a case to avoid contamination or damage to
the knife-edge.
Note: Special cleaning procedures may be required for other test methods (for example, metals or
dioxin).
5. Clean the Glassware (Filter Assemblies, Impingers and Connecting Glassware) internally by wiping
grease from the joints, washing with glass cleaning detergent, rinsing with distilled/deionized water,
and then rinsing again with reagent-grade acetone, before allowing to air-dry. To avoid contamination,
cover all exposed openings with parafilm, plastic caps, serum caps, ground-glass stoppers or aluminum
foil (do not use foil with metals).
Note: Special cleaning procedures may be required for other test methods (for example, metals or
dioxin).
Part 2: Preliminary Determinations
1. Select the sampling site, measure the stack or duct dimensions and determine the number of traverse
points (see Method 1).
2. Determine the stack gas pressure, range of velocity pressure heads and temperature (see Method 2).
3. Select the proper differential pressure gauge (see Method 2).
4. Determine or estimate the dry molecular weight (see Method 3).
5. Determine the moisture content (see Method 4).
6. Select a suitable Probe Assembly length such that all traverse points can be sampled.
63
7. Select a nozzle size and determine the K-factor for an isokinetic sampling rate. Important: Do not
change the nozzle size during the sampling run.
8. Select the total sampling time and standard gas sample volume specified in the test procedures for the
specific industry. Select equal sampling times of more than 2 minutes per traverse point.
Part 3: Preparation of Sampling Train
1. Mark the Probe Assembly with heat-resistant tape or “Wite-Out” to denote the proper distance into the
stack or duct for each sampling point (See Method 1).
2. Insert the Probe Nozzle into the probe sheath union and hand-tighten the union fitting. Avoid over-
tightening to prevent cracking of the glass probe liner. Keep the nozzle tip and ball joint on the glass
probe liner covered until you complete the train assembly and are about to begin sampling. Secure the
Probe Assembly to the Sample Case by tightening the probe clamp.
3. Prepare each set of impingers for a sampling run:
a. Impingers 1 & 2: 100 ml water in each
b. Impinger 3: Empty
c. Impinger 4: 200 to 300 g of silica gel
TIP: You can prepare more than one sampling run at once by using multiple sets of glassware!
4. Weigh each impinger to the nearest ± 0.5 g using a top-loading electronic balance (BAL-1200) and
record initial weights on a field data sheet.
Figure 2-23: Top-Loading Electronic Balance
5. Assemble the impingers in the Cold Box with U-tubes, Double “L” Adapter, and the Sample
Case/Umbilical Adapter, using Ball Joint Clamps or Clips. See Figure 2-24.
64
Figure 2-24: Top View of Assembled Impingers
Figure 2-25: Exploded View of Filter Assembly
6. Using tweezers or clean disposable surgical gloves, place the tared filter on the grooved (inlet) side of
the Teflon Frit (TFE) filter support in the Filter Holder. Check the filter for tears after placement, and
center it on the filter support. Assemble the Filter Holder (as shown in Figure 2-25), and tighten the
clamps around the Filter Holder to prevent leakage around the O-ring. Record filter number on the field
data sheet.
7. Using Ball Joint Clamps, connect the Filter Holder and Cyclone Bypass (GN-1) in the Hot Box to the
Probe Liner ball joint and to the “L” Adapter. Close the Hot Box doors and fasten shut.
Figure 2-26: Assembled Sampling Train Before Umbilical Hookup
65
8. Connect the Umbilical Cable electrical and pitot tube lines to the assembled sampling train and to the
Source Sampler Console. If applicable, also connect the Orsat line.
9. Place the assembled sampling train near the first sample port, either on the monorail or with other
support.
10. Turn on and set Probe and Hot Box heaters. Allow the Hot Box and Probe to heat for at least 15 minutes
before starting the test, and then make periodic checks and adjustments to ensure the desired
temperatures. Check all thermocouple connections by dialing through each selection and noting
ambient or heated temperatures. Place crushed ice and a little water around the impingers.
11. Optional: Leak-check the sampling train (see Leak-Check Procedure for Isokinetic Sampling Trains in
Reference Method 4 on page 50, and Pitot Tube and Line Leak-Check Procedures in Method 2 on page
41).
Part 4: Sampling Run Procedure
1. Open and clean the portholes of dust and debris.
2. Level and zero manometers that gauge Δp (avg. stack gas velocity head) and ΔH (avg. orifice tube
pressure).
3. Record data on a field data sheet. Record the initial dry gas meter (DGM) reading.
4. Remove the nozzle cap, verify that the Hot Box/filter and probe heating systems are up to temperature,
and check alignments and clearances for the pitot tube, temperature gauge and probe.
5. Close the Coarse Valve and fully open the Fine Increase Valve. Position the nozzle at the first traverse
point. Record the clock time, read Δp on the manometer, and determine ΔH from the nomograph.
6. Immediately start the pump and adjust the flow to set the orifice tube pressure (ΔH), first by adjusting
the Coarse Valve and then the Fine Increase Valve.
Note: If necessary to overcome high negative stack pressure, turn on the pump while positioning the
nozzle at the first traverse point.
7. When the probe is in position, block off the openings around the probe and porthole using duct tape,
rags, gloves or towels (make sure the materials are flameproof for hot stacks).
66
Figure 2-27: Blocking off the Porthole During Sampling
8. Record readings for the ΔH manometer and pump vacuum, as well as temperatures for stack gas, DGM,
filter box, probe, and impinger exit.
9. Record the ID numbers for the DGM, thermocouples, pitot tube, and Sample Box.
10. If simultaneously running a Method 3 gas bag collection, turn on the Orsat pump. Turn Orsat pump off
during port changes.
11. Traverse the stack cross-section for the same time period at each point without turning off the pump,
except when changing ports.
Important: Do not bump the probe nozzle into the stack walls.
a. Make periodic adjustments to maintain the Hot Box temperature (around the filter holder) at
the proper level.
b. Monitor the Δp (gas velocity head) during sampling of each point. If the Δp changes by more
than 20%, record another set of readings.
c. Periodically check the level and zero of the manometers and readjust if necessary.
d. Record DGM readings at the beginning and end of each sampling time increment, before and
after each leak-check, and when sampling is halted.
e. Take other readings (ΔH, temps, vacuum) at least once at each sample point during each time
increment to ensure the ΔH/Δp isokinetic ratio is maintained.
f. Add more ice and, if necessary, salt to maintain a temperature of less than 20°C (68°F) at the
silica gel impinger exit.
12. At the end of the sample run, turn off the Coarse Valve, remove the probe and nozzle from the stack,
turn off the pump and heaters, and record the final DGM reading.
13. Mandatory: Leak-Check the sampling train (See Method 4, page 50) at the maximum vacuum achieved
during the sample run. Record leak-check results on field data sheet.
14. Mandatory: Leak-Check the pitot lines (See Method 2, page 41). Record results on field data sheet.
15. Allow the probe to cool. Wipe off all external particulate material near the tip of the probe nozzle and
cap the nozzle to prevent contamination or sample loss.
Hint: Open the Hot Box doors to allow the filter holder to cool.
16. Before moving the sampling train to the clean-up site, disconnect the probe from the Cyclone Bypass
inlet and cover both ends. Avoid losing any condensate that might be present. Disconnect the Filter
Holder from the “L” Adapter and cap off the Filter Holder.
17. Disconnect the Umbilical Cable from the Sample Box and cover the last impinger outlet and first
impinger inlet. Disconnect the Cold Box from the Hot Box. Now, the Probe/Nozzle Assembly, Filter
Holder, and impinger case are ready for sample recovery.
18. Transfer the probe and filter-impinger assembly to an area that is clean and protected from the wind.
Part 5: Variations and Alternatives
67
1. Acceptable alternatives to glass probe liners are metal liners; for example, 316 stainless steel, Inconel,
or other corrosion-resistant metals made of seamless tubing. These liners can be useful for cross-
sections over 3 m (10 ft.) in diameter.
2. For large stacks, consider sampling from opposite sides of the stack to reduce the length of the probe.
3. Use either borosilicate or quartz glass probe liners for stack temperatures from 480° to 900°C (900–
1,650°F). The softening temperature for borosilicate glass is 820°C (1,508°F); for quartz, it is 1,500°C
(2,732°F).
4. Rather than labeling filters, label the shipping containers (glass or plastic petri dishes) and keep the
filters in these containers at all times except during sampling and weighing.
5. Use more silica gel in impinger 4, if necessary, but ensure that there is no entrainment or loss during
sampling.
Hint: Loosely place cotton balls or glass wool in the neck of the silica gel impinger outlet stem to avoid
spillage.
6. If you are using a different type of condenser (other than impingers), measure the amount of moisture
condensed either volumetrically or gravimetrically.
7. For moisture content, measure the impinger contents volumetrically before and after a sampling run.
Use a pre-weighed amount of silica gel in a shipping container. Then, after the run, empty the silica gel
back into the container for weighing at another time.
Tips from a Stack Tester
Whenever practical, make
every effort to use
borosilicate glass or
quartz probe liners. Metal
liners will bias particulate
matter results higher than
actual.
68
Figure 2-28: Recover Silica Gel for Weighing Figure
2-29: Determine Moisture Volumetrically
8. If you expect the total particulate catch to
exceed 100 mg or more, or when water droplets
are present in the stack gas, use a Glass Cyclone
between the probe and Filter Holder.
9. If you have difficulty maintaining isokinetic
sampling due to high pressure drops across the
filter (with a high vacuum on the gauge), replace
the filter.
10. Use a single train for the entire sampling run,
except when:
a. Simultaneous sampling is required in
two or more separate ducts, or
b. Simultaneous sampling is required at
two or more different locations within
the same duct, or
c. Equipment failure necessitates a change in trains.
In all other situations, obtain approval from the regulatory agency before using two or more trains.
11. When using two or more trains, analyze separately the front-half and (if applicable) impinger catches
from each train, unless you used identical nozzle sizes on all trains. In this case, you may combine the
front-half catches (and the impinger catches) and perform one analysis of the front-half catch and one
analysis of the impinger catch. Consult with the regulatory agency for details concerning the calculation
of results when using two or more trains.
12. If using a flexible line between the first impinger or condenser and the Filter Holder, disconnect the
line at the Filter Holder and let any condensed water or liquid drain into the impingers or condenser.
13. Do not cap off the probe tip too tightly while the
sampling train is cooling down as this would
create a vacuum in the Filter Holder, which may
draw water from the impingers into the Filter
Holder.
Part 6: Sample Recovery
Note: Sample Recovery is an extremely important step
that requires a high level of precision. If sample loss
occurs, your results will be biased low, and if sample
contamination occurs, your results could be biased
high.
Tips from a Stack Tester
You can opt to use another filter
assembly, rather than changing the
filter itself. Remember to conduct a
leak-check before installing a new
filter. Add the filter assembly
catches to the total particulate matter
weight.
Tips from a Stack Tester
Instead of trying to catch the probe
rinse with a glass funnel and sample
container (which can easily result in
sample loss), clamp an Erlenmeyer
flask outfitted with a female ball joint
on the probe liner ball joint when
conducting the probe rinse
procedure. If the probe is short, one
person can perform the brushing and
rinsing.
69
1. Place 200 ml of acetone from the wash bottle you are using for clean-up in a glass sample container
labeled “Acetone Blank.”
2. Inspect the train prior to and during disassembly and note any abnormal conditions on the data sheet.
3. Container No. 1: Filter
a. Using a pair of tweezers (TW-1) and/or clean disposable surgical gloves, carefully remove the
filter from the Filter Holder and place it in its identified petri dish container. If necessary, fold
the filter so that the particulate matter cake is inside the fold.
b. Using a nylon bristle brush (DB-3) and/or a sharp-edged blade (LS-1), carefully transfer to the
petri dish any particulate matter (PM) and/or remaining pieces of filter or filter fibers that
adhered to the filter support or gasket.
4. Container No. 2: Acetone Rinses
Note: Recover all of the rinses listed here in a single glass container.
a. Recover any PM from the internal surfaces of the Probe Nozzle, swaged union fitting, front half
of the Filter Holder, cyclone (if applicable), and probe liner (use a glass funnel to aid in
transferring the liquid wash to the container, see figure 2-30).
b. Before cleaning the front half of the Filter Holder, wipe all joints clean of silicone grease.
c. Rinse with acetone, brush with a small nylon bristle brush, and rinse with acetone again until
there are no visible particles (see figures 2-31 and 2-32). Make a final acetone rinse.
d. For the probe liner, repeat the rinse-brush-rinse sequence at least three times for glass liners and
six times for metal liners.
e. Make a final rinse of the probe brush with acetone.
f. For the Probe Nozzle, use the nylon nozzle brush and follow the same sequence of rinse-brush-
rinse as with the probe liner.
g. After completing the rinse, tighten the lid on the sample container. Mark the height of the fluid
level and label the container.
70
Figure 2-30: Sample Recovery from Probe Liner
Figure 2-31: Rinsing Probe Nozzle
Figure 2-32: Brushing Probe Nozzle
Figure 2-33: Front Half of Acetone Rinse Samples
5. Container No. 3: Silica Gel
a. Determine whether silica gel has been completely spent, and note its condition and color on
the data sheet.
b. Discard and reload the impinger. Alternatively, you can reuse the impinger in the next run,
using the final weight from this run as the initial weight for the new sampling run.
6. Impinger Water
a. Note on the data sheet any color or film in the liquid catch.
71
b. Discard the liquid, unless you are required to do an analysis of the impinger catch. Store as is
appropriate.
Note: Whenever possible, ship sample containers in an upright position.
Calculations at the End of the Sampling Run
At the conclusion of each sampling run, it is prudent to calculate the stack gas moisture (for the next
sampling run), as well as the average isokinetic rate.
To calculate the stack gas moisture content (Bws), use the following equations to compute the sample gas
volume (Vm(std)) and gas moisture volume (Vwc(std)):
Sample Gas Volume:
where K3 = 0.3858 °dK/mm Hg (metric units), or 17.64 °R/in. Hg (English units)
Y = Dry gas mater calibration factor
Vm = Dry gas volume measured by dry gas meter, dcm (dcf)
Pbar = Barometric pressure at measurement site, mm Hg (in. Hg)
ΔH = Average orifice tube pressure during sampling, mm H2O (in. H2O)
Tm = Absolute temperature at dry gas meter, °K (°R)
Gas Moisture Volume:
where K2 = 0.001335 m3/g (metric units), or 0.04715 ft3/g (English units)
Wf = Final weight of water collected, g
Wi = Initial weight of water collected, g
Stack Gas Moisture Content:
72
where Bws = Proportion of water vapor, by volume, in the gas stream
Vwc(std) = Gas moisture volume (see equation above)
Vm(std) = Sample gas volume (see equation at top of page)
Average Stack Gas Velocity:
Next, calculate the average stack gas velocity. The equation for average gas velocity in a stack or duct is:
where Vs = Average stack gas velocity, m/sec (ft/sec)
Kp = Constant, 34.97 for metric system (85.49 for English system)
Cp = Pitot tube coefficient, dimensionless
(√Δp)avg = Average of the square roots of each stack gas velocity head
Ts = Absolute average stack gas temperature, °K (°R)
Ps = Absolute stack gas pressure, mmHg (in. Hg), calculated with the equation:
Ps = Pbar + Pg/13.6
Pbar = Barometric pressure at measurement site, mm Hg (in. Hg)
Pg = Stack static pressure, mm H2O (in. H2O)
Ms = Molecular weight of stack on wet basis, g/g-mole (lb/lb-mole), calculated with
the equation: Ms = Md (1-Bws) + 18.0 (Bws)
Md = Molecular weight of stack on dry basis, g/g-mole (lb/lb-mole)
Bws = Proportion of water vapor, by volume, in the gas stream
Isokinetic sampling rate:
The average percent isokinetic sampling rate is calculated as:
73
where K4 = 4.320 (metric units) or
0.09450 (English units)
Ts = Absolute average stack
gas temperature, °K (°R)
Vm(std) = Sample gas volume
Ps = Absolute stack gas
pressure, mmHg (in. Hg), calculated
with the equation:
Ps = Pbar + Pg/13.6
Pbar = Barometric pressure at
measurement site, mm Hg (in. Hg)
Pg = Stack static pressure,
mm H2O (in. H2O)
Vs = Average stack gas
velocity, m/sec (ft/sec)
An = Cross-sectional area of
the nozzle, m2 (ft2)
θ = Sampling time, minutes
Bws = Proportion of water vapor, by volume, in the gas stream
Recommended Reading List for Isokinetic Sampling
● Code of Federal Regulations. Title 40. Part 60, Appendix A. Office of the Federal Register. National
Archives and Records.
● Compliance Test Coordination and Evaluation. Workshop Manual. U.S. Environmental Protection
Agency. APTI 01-94a. 1994.
● Jahnke, J. A., et al. Source Sampling for Particulate Pollutants. Student Manual, APTI Course 450.
Edition 3.0. Raleigh, NC: North Carolina State University, 1995.
Tips from a Stack Tester
During port changes, many stack testers scan or
quickly average values for p, H, stack gas
temperature, and DGM temperature to calculate %I
before the sampling run is finished (this all assumes
that Bws will not change substantially). Some
sophisticated calculator programs and most laptop
computer programs monitor %I for each point and
cumulatively.
74
● Manual for Coordination of VOC Emissions Testing Using EPA Methods 18, 21, 25, and 25A. U.S.
Environmental Protection Agency. EPA 340/1-91-008. September 1991.
● Quality Assurance Handbook for Air Pollution Measurement Systems. Vol. 3. Stationary Source
Specific Methods, Section 3.4. U.S. Environmental Protection Agency. EPA-600/4-77-027b. 1988.
● Rom, J. J. Maintenance, Calibration, and Operation of Isokinetic Source Sampling Equipment.
Publication No. APTD-0576. Office of Air Programs. U.S. Environmental Protection Agency.
Research Triangle Park, NC. 1972
Chapter 3
Calibration and Maintenance
Establishing and adhering to a routine maintenance program is beneficial in two ways. First, properly
maintaining the isokinetic sampling system helps to ensure trouble-free operation. Secondly, carefully
documenting your maintenance and calibration system will help you obtain the most accurate results during
stack testing activities.
This chapter describes calibration, maintenance and troubleshooting procedures for the various subsystems of
the isokinetic sampling system.
Calibration Procedures
It is critical to create and maintain a regularly scheduled calibration and record-keeping protocol for your
stack testing program. If you fail to ensure proper calibrations, you will not be able to verify that the test was
conducted isokinetically and your stack emission test results will be meaningless.
The results of a particulate sampling test cannot be checked for accuracy because no independent technique
or test atmosphere exists to provide a standard or known particle concentration. Collaborative testing
conducted by the US EPA has determined that the interlaboratory standard deviation is ± 12.1%. Only
through careful calibration, maintenance and record keeping can you ensure that the data collected during the
stack test is representative of the site’s particle concentrations and mass emission rate.
The particulate sampling system components that require calibration are:
1. Dry Gas Meter and Orifice Tube,
2. Thermocouples (Stack, Probe, Filter Box, Impinger Exit, and Dry Gas Meter) and Digital
Temperature Indicator,
3. Pitot Tube,
75
4. Sampling Nozzles, and
5. Probe and Filter Box Heater System.
Table 3-1 presents a summary of the components that require calibration and the equipment used to do so, as
well as acceptable calibration factor limits, recommended calibration frequency, and steps to take if your
system fails to meet calibration acceptance limits.
Component
Calibrated Against
Calibration Factor
Y Acceptance Limits Frequency
Action If
Unacceptable
Dry Gas Meter Initial 5-point
1. Wet Test Meter 2. Secondary Reference DGM
Yi = Y ± 0.05Y Semiannually Recalibrate, repair
or replace
Post-test 3-point 1. Wet Test Meter 2. Reference DGM 3. Critical Orifices
Y = Y ± 0.05Yavg After each field
test Recalibrate at 5-
points
Orifice Tube Measured during DGM
calibration ΔH@ = 46.7 ± 6.4 mm
H2O (1.84 ± 0.25 in.
H2O)
With DGM Repair or replace
Thermocouples and
Digital Indicator Certified Hg-in-glass
thermometer in ice
slush and boiling water
Stack: ±1.5% °K DGM: ±3°C Probe: ±3°C Filter: ±3°C Exit: ±1°C
After each field
test Recalibrate, repair
or replace
Pitot Tube 1. Standard pitot tube
in wind tunnel and
calculate Cp (pitot tube
coefficient)
If part of Probe
Assembly, calibrate
with assembly.
σ (avg. deviation) ≤
0.001 for side A & B
Quarterly, or after
each field test Recalibrate, repair
or replace
2. Measure with angle
indicator to
demonstrate meeting
geometric
specifications and
assign Cp = 0.84
α1 ± 10° α2 ± 10° β1 ± 5° β2 ± 5° Z = ≤ 0.125” W = ≤ 0.031” PA - PB ≤ 0.063” 0.188” ≤ DT ≤ 0.375”
Quarterly, or after
each field test Recalibrate, repair
or replace
Sampling Nozzles Micrometer with at
least 0.025-mm (0.001-
in.) scale
Average of 3 inner
diameter
measurements; ΔD ±
0.1-mm (0.004-in.)
Before each field
use Recalibrate,
reshape, or
resharpen when
dented or
corroded
76
Probe and Filter Box
Heater System Gas thermocouple Capable of
maintaining 120°C ±
14°C at 20-lpm flow
rate
Initially Repair or replace,
and verify
calibration
Table 3-1: Sampling System Equipment Calibration and Frequency
1. Calibration of Dry Gas Meter and Orifice Tube
Calibrate the dry gas meter and Orifice Tube simultaneously (reference US EPA Method 5, Section 5.3 for
the calibration procedure). In short, you should:
• Conduct an initial (or full) calibration at five (5) selected flow rate (ΔH) settings.
• Repeat the procedure once every 6 months, or if the results of a post-test 3-point calibration show
that the dry gas meter calibration factor (Y) has changed by more than 5% from the pre-test
calibration value.
When performing quarterly or post-test calibrations, use the abbreviated calibration procedure described in
Section 5.3.2 of Method 5, which includes three (3) calibration runs at a single intermediate flow rate (ΔH)
setting.
The dry gas meter (DGM) calibration factor (Y) is the ratio of the wet test meter’s measured volume to the
dry gas meter’s measured volume. The DGM calibration factor is part of calibrating the Source Sampler
Console.
The Orifice Tube calibration factor (ΔH@) represents the pressure drop across the orifice for a sampling flow
rate of 21.2 lpm (0.75 cfm), which is the standard sampling rate for solving the isokinetic equation and
setting up the nomograph (sets of equations) for testing.
Find the true Orifice Tube calibration factor with the following equation, where Km is the orifice calibration
factor:
ΔH@ = 0.9244/Km2
Described below are both the initial and intermediate calibration procedures. Prior to conducting a
calibration run, perform a leak-check on the portion of the sampling train from the pump to the Orifice Tube
in the Source Sampler Console, as described below.
Metering System Leak-Check Procedure (Vacuum Side):
The following steps describe the leak-check procedure for the Vacuum Side of the Source Sampler Console.
See Figure 3-1 for a plumbing diagram of the MC-500 Series Source Sampler Console.
1. Connect the Vacuum Pump to the Source Sampler Console.
77
2. Close the Coarse Valve on the Source Sampler Console.
3. Insert a plugged male quick-connect into the SAMPLE quick-connect inlet.
4. Turn on the pump.
5. Open the Coarse Valve and fully close the Fine Increase Valve.
6. The Vacuum Gauge should read 92-kPa (27 in. Hg) for a barometric pressure of 100 kPa (30 in.
Hg).
7. After the ΔH manometer has returned to the zero mark, note whether the leak rate exceeds 0.28
lpm (0.01 cfm) using the dry gas meter gauge and a wristwatch or timer. If the leak rate is too
high, turn off the Pump and check tubing and piping connections on the Pump, Vacuum Gauge,
and Metering Valves. Also check the tubing for leaks.
8. Close the Coarse Valve and observe the Vacuum Gauge. If there is no vacuum loss, the vacuum
side of the Source Sampler Console is leak free.
9. Perform the Pressure Side Leak-Check next by following the directions in the next section.
Note: The Rockwell Dry Gas Meter in the MC-522 (English version of the MC-572) will indicate a leak by
running backward on the Pressure Side when completing the Vacuum Side Leak-Check. However, the
Kimmon Dry Gas Meter in the MC-572 will not run backward, thus requiring a Pressure Side Leak-Check.
Figure 3-1: Source Sampler Console Plumbing Diagram for Leak-Check
78
Metering System Leak-Check Procedure (Pressure Side):
There are several techniques for performing a “back-half,” or pump discharge, Source Sampler Console leak-
check. The following procedure is based on US EPA recommendations in Section 5.6 of Method 5:
1. Connect the Vacuum Pump to the Source Sampler Console.
2. Plug the outlet of the Orifice Meter with a rubber stopper.
3. Insert both pitot (Δp) manometer plastic connectors into the right side of the dual-column
manometer.
4. Insert both orifice (ΔH) manometer plastic connectors into the left side of the dual-column
manometer.
5. To pressurize the system, remove one of the ΔH plastic connectors and then blow lightly into the
tubing until the ΔH reads 177.8 to 254 mm (7 to 10 in.) H2O.
6. Pinch off the tubing securely, and insert the ΔH plastic connector back into the manometer. Allow
the manometer oil time to stabilize.
7. Observe for one minute. If you note any loss of pressure during this minute, you have a leak
which must be corrected. Check all connections and tubing for leaks.
Initial or Semiannual Calibration of Dry Gas Meter and Orifice Tube:
Calibrate the Source Sampler Console (Dry Gas Meter and Orifice Tube) by connecting the Source Sampler
Console to a wet test meter or secondary reference dry test meter, according to the set-ups shown in Figures
3-2 and 3-3.
Conduct a series of five (5) calibration runs at differing flow rates (ΔH settings) that bracket the range of
expected sampling rates during particulate sampling tests.
If using a wet test meter as the calibration standard, it should have a meter correction factor of 1.000.
Alternatively, you may use a properly calibrated secondary reference dry gas meter to calibrate the Source
Sampler Console’s dry gas meter.
The calibration steps are as follows:
1. Before starting the calibration, record the following data on a meter calibration data sheet (or a
computer spreadsheet) as shown in Appendix C:
a. Barometric pressure at the start of calibration,
b. The Source Sampler Console and wet test meter identification numbers
c. Date and time of calibration, and
d. Confirmation of acceptable leak-checks on the Source Sampler Console.
2. Connect the outlet of the wet test meter to the inlet (SAMPLE) of the Console Meter.
3. Turn on the Vacuum Pump and adjust the Coarse and Fine Control Valves on the Source Sampler
Console until you obtain an orifice pressure (ΔH) of 12.7 mm (0.5 in.) H2O at a vacuum of 8 to 15
79
kPa (2 to 4 in. Hg) on the Vacuum Gauge. Allow both
meters to run in this manner for at least 15 minutes to let
the meter stabilize and the wet test meter to wet the
interior surfaces.
4. Turn off the Vacuum Pump.
5. Record initial settings of ΔH, dry gas meter volume
reading, wet test meter volume reading, dry gas meter
temperature, and wet test meter temperature.
6. Start the Vacuum Pump and quickly adjust the ΔH to the
desired setting. Start the Elapsed Timer on the Source
Sampler Console at the same time you start the pump.
7. Let the Vacuum Pump run until a dry gas volume of
approximately 140 liters (5 cubic feet) is indicated on the
dry gas meter. Allow the calibration run to continue until
the next minute elapses, and then stop the Vacuum Pump
and Elapsed Timer.
8. Record the final dry gas meter volume reading, wet test meter volume reading, dry gas meter
temperature, and wet test meter temperature. Calculate the dry gas meter and wet test meter volumes
by subtracting initial readings from final readings. Calculate the average dry gas meters and wet test
meter temperatures.
9. Repeat the calibration run at each successive setting of ΔH, recording the same data as before.
Suggested ΔH values are 13, 26, 39, 52, 65 and 78 mm H2O (0.5, 1.0, 1.5, 2.5, 3.5 and 4.5 in. H2O).
10. At the conclusion of the five calibration runs, calculate the average Y value to obtain the dry gas
meter calibration factor, as well as the average orifice pressure (ΔH@). The tolerance for individual Y
values is ± 0.02 from the average Y. The tolerance for individual ΔH@ values is ± 6.4 mm (0.25 in)
H2O from the average ΔH@.
11. If the Y and ΔH@ are acceptable, record the values on a label on the front face of the Console Meter.
Tips from a Stack Tester
If you don’t obtain a value
of ± 6.4-mm (0.25-in)
H2O from the average
ΔH@, adjust the orifice
opening or replace the
Orifice Tube.
80
Figure 3-2: Set-up for Calibrating the Source Sampler Console Against Wet Test Meter
Figure 3-3: Illustration of Console Meter Calibration with Secondary Reference Dry Gas Meter
81
Figure 3-4: Critical Orifice Used for Calibration
Post-Test Calibration of the Source Sampler Console:
Conduct a post-test, or 3-point, calibration of the Source
Sampler Console after each test series or trip to and from the field
to ensure that the dry gas meter correction factor (Y) has not
changed by more than 5%.
Conduct the post-test calibration check at the average ΔH and
highest system vacuum observed during the test series. The steps
are as follows:
1. Before starting the calibration, fill out a meter
calibration data sheet (it can be a computer
spreadsheet) as shown in Appendix C. Record the
following:
a. Barometric pressure at the start of
calibration,
b. Identification numbers for the Source
Sampler Console and wet test meter (or
secondary DGM or critical orifice),
c. Date and time of calibration, and
Tips from a Stack Tester
With a critical orifice set
as shown in Figure 3-4,
you can do a post-test
calibration in the field
before departing the test
site. Follow the same
directions described on
the next page, except
substitute the critical
orifice for the wet test
meter and ensure that the
vacuum is 25 to 50 mm
Hg (1 to 2 in. Hg) above
the critical vacuum.
82
d. Confirmation of acceptable leak checks on the Source Sampler Console.
2. Connect the outlet of the wet test meter to the inlet (SAMPLE) of the Source Sampler Console, as
depicted in Figure 3-2. Insert a valve between the wet test meter and the inlet of the Source Sampler
Console to adjust the vacuum to the desired level. If using a Critical Orifice, simply insert the male
quick-connect end of the critical orifice into the inlet (SAMPLE) of the Source Sampler Console.
3. Turn on the Vacuum Pump and adjust the Coarse and Fine Control Valves on the Source Sampler
Console until you obtain an orifice differential pressure (ΔH) reading equivalent to the average ΔH
observed during the test series. Set the calibration system vacuum to the highest vacuum observed
during the test series. Allow both meters to run like this for at least 15 minutes to let the meter stabilize
and the wet test meter to wet the interior surfaces.
4. If using a Critical Orifice, select an orifice with ΔH properties similar to the average ΔH observed
during the test series. Note that the vacuum will be independent of the vacuum observed during the test
series, due to the physics of the critical orifice requiring the vacuum to be greater than the theoretical
critical vacuum. Theoretical critical vacuum can be estimated at one-half (1/2) of barometric pressure.
It is recommended to sample at 1-2 inches Hg (25-50 mm Hg) above the critical vacuum with the
Coarse Valve fully opened and the Fine Valve adjusted.
5. Turn off the Vacuum Pump.
6. Record initial settings of ΔH, dry gas meter volume reading, wet test meter volume reading, dry gas
meter temperature, and wet test meter temperature.
7. Start the Vacuum Pump and quickly adjust the ΔH to the desired setting. Start the Elapsed Timer on
the Source Sampler Console at the same time that the pump is started.
8. Let the Vacuum Pump run until the dry gas meter indicates a volume of approximately 140 liters (5
cubic feet). Allow the calibration run to continue until the next minute elapses, and then stop the
Vacuum Pump and Elapsed Timer.
9. Record the final dry gas meter volume reading, wet test meter volume reading, dry gas meter
temperature, and wet test meter temperature. Calculate the dry gas meter and wet test meter volumes
by subtracting initial readings from final readings. Calculate the average dry gas meter and wet test
meter temperatures.
10. Calculate the meter correction factor Y. Repeat the calibration two (2) more times at the same ΔH and
system vacuum settings and calculate the average Y for the three runs.
11. Calculate the percent change in the meter correction factor Y.
12. If the dry gas meter Y values obtained before and after the test series differ by more than 5%, either
void the test series or perform calculations for the test series using the lower Y value (which would
give a lower sample volume, and therefore higher concentration values).
2. Calibration of Thermocouples
Apex Instruments suggests the following procedures for calibrating thermocouples and temperature display
readouts:
● Check thermocouples for calibration at three temperatures. For example, ice-point and boiling point of
water and ambient temperature. Thermocouples that are used at higher temperatures than boiling water,
such as the stack gas thermocouples, can be checked for calibration using a hot oil bath.
83
● Another more modern technique is to use a Thermocouple Simulator Source (M5C-22), as shown in
Figure 3-5. The M5C-22 can calibrate without external compensation or ice baths, with a temperature
range from 0° to 2,100°F in divisions of 100°F, resulting in 22 precise test points.
A temperature sensor calibration form is provided in Appendix C.
Acceptable reference materials are:
● ASTM reference thermometers,
● NIST-calibrated reference thermocouples/potentiometers,
● Thermometric fixed points, e.g., ice bath and boiling water
● NIST-traceable electronic thermocouple simulators.
Thermocouple Calibration Procedure:
1. Prepare an ice-water bath in an insulated container (such as
the Cold Box).
a. Insert the thermocouple and a mercury reference thermometer into the bath.
b. Allow the readings of both to stabilize and record the temperatures on a thermocouple
calibration data sheet, as shown in Appendix C.
c. Remove the thermocouple and allow it to stabilize at room temperature.
d. Reinsert the thermocouple into the bath and record another reading.
e. Repeat Steps c and d.
f. Calculate the average of the thermocouple readings and the average of the reference
thermometer readings. The averages should differ by less than 1.5% of the absolute temperature
(°K) for the stack thermocouple.
2. Place a beaker of distilled water on a hot plate, and then add a few boiling chips and heat to boiling.
a. Insert the thermocouple and a mercury reference thermometer into the beaker and repeat Step
1, b through f, above.
3. Set the thermocouple you are checking and a mercury reference thermometer side-by-side at ambient
temperature and allow the readings to stabilize.
a. Repeat Step 1, a through f, above.
4. Place a container of oil on a hot plate and heat to a temperature below the boiling point. DO NOT
BOIL.
a. Insert the thermocouple and a mercury reference thermometer into the container and repeat Step
1, b through f, above.
Figure 3-5:
Thermocouple Simulator for
Temperature Display Calibration Check
84
Calibrate Temperature Display:
The
temperature display requires additional calibration procedures. To check the linearity of the temperature
display, use a thermocouple simulator (such as Apex Model M5C-22 pictured in Figure 3-5). Connect the
simulator to the temperature display and record the display reading at each temperature setting on a calibration
data sheet.
3. Calibration of Pitot Tube
Carefully check the construction details of the S-type (or Stausscheibe) pitot tube when you receive it and prior
to calibration. There are two options for calibrating a S-type pitot tube:
Option 1: Since few stack testers have access to a wind tunnel facility, the US EPA allows you to assign a co-
efficient of Cp = 0.84, if the pitot tube meets geometric specifications. Keep in mind that using the agency’s
standard co-efficient will likely bias your velocity and flow rate measurements high.
Option 2: When using a wind-tunnel calibration procedure, the pitot tube coefficient (Cp) will typically range
from 0.77 to 0.82. This means that your subsequent measurements of stack gas velocity will likely be between
2% and 8% lower due to increased accuracy associated with wind-tunnel calibration. Consequently, your
measurements of the stack gas volumetric flow rate and emission rate also will be lower. The procedures for
conducting a wind tunnel calibration are described in detail in US EPA Method 2.
Calibration Of
S-type Pitot Tube
Check that it meets
geometric
specifications and
assign Cp = 0.84
Calibrate against
standard p-type in a
wind tunnel and
calculate new Cp
OR
Did you know? Apex Instruments provides both geometric and wind tunnel
calibrations of type-S pitot tube assemblies for a reasonable fee. Contact us at (800)
882-3214 to learn more.
85
Geometric Specifications Pitot Calibration:
1. Before starting the calibration check, fill out a pitot tube
calibration data sheet as shown in Appendix C (or enter it
in a spreadsheet).
2. Clamp the pitot tube so that it is level, verify its level
position and record it.
3. Confirm that the pitot openings are not damaged or
obstructed and record it.
4. Using an angle indicator, measure the angles (α1 and α2)
between the pitot tube opening plane and the horizontal
plane when viewed from the end, and record the angles (see
third image in figure 3-6).
5. Measure the angles (β1 and β2) between the pitot tube
opening plane and the horizontal plane when viewed from
the side, and record the angles (see fourth image in the
figure).
6. Calculate the difference in length between the two pitot tube
legs (Z) by measuring the angle γ and record it (see the last
image in the figure).
7. Calculate the distance that the pitot tube legs are rotated (W)
by measuring the angle θ and record it (see the fifth image
in the figure).
8. Measure and record the vertical distances (PA and PB)
between the plane of each pitot tube opening and the center
line of the pitot tube (see the second image in the figure).
9. Measure and record the tube external diameter (DT) and
calculate the minimum/maximum values of PA and PB (see
first image in figure).
Figure 3-6
Probe Pitots measurements pertaining
to the geometric specifications
calibration check
86
4. Calibration of Sampling Nozzles
Inspect and calibrate probe nozzles in the field immediately before each use to verify that they were not
damaged in transport or shipment. We recommend the following procedure, illustrated in Figure 3-7:
1. Before starting the calibration check, fill out a probe nozzle calibration data sheet as shown in
Appendix C (or use a computer spreadsheet).
2. Using venier or dial calipers with at least 0.025 mm (0.001 in.) tolerance, measure the inside diameter
of the nozzle by taking three readings approximately 45-60° apart from one another, and record them.
3. Calculate the average of the three readings.
4. If readings do not fall within 0.1 mm (0.004 in.) of one another, the nozzle must be reshaped,
resharpened and recalibrated.
5. With a permanent marking tool, identify each nozzle with a unique number.
Figure 3-7: Calibration of Sampling Nozzle
87
5. Initial Calibration of Probe Heater
Apex Instruments calibrates the probe heater assembly before shipping according to procedures outlined in US
EPA APTD-0576. Probes are constructed according to specifications given in US EPA APTD-0581, which is
the original 1971 document entitled “Construction Details of Isokinetic Source-Sampling Equipment,” by
Robert M. Martin. (Available from National Technical Information Service (NTIS) as document PB-203 060.)
The procedure outlined in APTD-0576 involves passing heated gas at several known temperatures through a
probe assembly, and monitoring and verifying that the probe assembly is capable of maintaining 120°C ±
14°C, as shown in Figure 3-8.
Figure 3–8: Set-up for Probe Heater Calibration
88
6. Calibration of Pressure Sensors
The gauge-oil inclined manometer and a mercury-in-glass manometer are primary measuring devices, and
thus do not require calibration. When using a differential pressure gauge (magnehelic gauge), U-tube
manometer, or electronic manometer, they must be calibrated against a primary measuring device.
To check the calibration of differential pressure sensors other than inclined manometers, use the following
procedure:
1. Connect the differential pressure sensor to a gauge-oil inclined manometer as shown in Figure 3-9.
2. Vent the vacuum side to atmosphere, and place a pressure on each system.
3. Compare Δp (velocity head of stack gas) readings of both devices at three or more levels that span
the range, and record on a calibration data sheet.
4. Repeat Steps 1 through 3 for the vacuum side. Vent the pressure side and for the vacuum side, place a
vacuum on the system.
5. The readings at the three levels must correspond within ± 5% of the reference sensor.
Magnehelic
1 2 4 .6
OR
Manometer
To vacuum system or
vented to atmosphere
To pressure source or
vented to atmosphere
Valve
Figure 3-9: Set-up for Differential Pressure Sensor Calibration Check
89
Maintenance Procedures
For maintenance procedures, check your appropriate user’s manual for the equipment that you are using for
your stack test.
If you are using Apex Instruments equipment, call 1 (800) 882-3214 to speak with a member of our
Technical Services Group (TSG) to aid you in your maintenance needs. Additionally, you may use our
website www.apexinst.com to find a user’s manual for your specific equipment that needs maintenance.
90
Appendix A
Equipment Lists for Isokinetic Sampling
91
Recommended Equipment for Isokinetic Sampling
Apex Instruments, Inc. Method 5 Source Sampling System recommended items:
Qty Part# Description
1 XC-5000 Automated Isokinetic Method 5 Meter Console includes DGM with Optical Encoder, Barometric
Pressure Transducer, Internal Flash Memory, Type K Thermocouples, PID, Standard or Metric Units
1 XE-0523 External Pump Assembly, Double Diaphragm Pump, SS Quick Connects, 5 FT Power Cord & Hoses,
240V (120V option), Black UHMW Polyethylene Case
1 SB-2M Miniature Heated Filter Oven with 2 Access Doors & Probe Clamp, 240V (120V option)
1 SBR-10 Riser for SB-2M, Impinger Box Adapter, 10 IN Riser with Insulated Reservoir
1 SB-3 Impinger Box / Insulated Coolant Reservoir, Holds 4 Impingers
1 PS-3H 3 FT Method 5 Probe Sheath with Tube Heater, 120V (240V option)
1 PS-6H 6 FT Method 5 Probe Sheath with Tube Heater, 120V (240V option)
1 PS-9H 9 FT Method 5 Probe Sheath with Tube Heater, 120V (240V option)
1 PL-3S 3 FT SS Probe Liner, 5/8” o.d. with #28 Grooved Ball
1 PL-6S 6 FT SS Probe Liner, 5/8” o.d. with #28 Grooved Ball
1 PL-9S 9 FT SS Probe Liner, 5/8” o.d. with #28 Grooved Ball
3 PLN-3G 3 FT Glass Probe Liner, 5/8” o.d. with Unground #28 Grooved Ball
3 PLN-6G 6 FT Glass Probe Liner, 5/8” o.d. with Unground #28 Grooved Ball
3 PLN-9G 9 FT Glass Probe Liner, 5/8” o.d. with Unground #28 Grooved Ball
1 US-30-10 30 FT Split Umbilical Cable, Method 5, with 1/4” Pitot QCs, Stainless Steel Quick Connects
1 US-60-10 60 FT Split Umbilical Cable, Method 5, with 1/4” Pitot QCs, Stainless Steel Quick Connects
1 USL-15-SST 15 FT Unheated Sample Line, PTFE with SS over braid, #28 Socket Elbow Fitting Both Ends,
Includes TCA-06F
1 SB-8 Modular Sample Frame with Probe Clamp & Impinger Box Slides
1 GA-107-12 Sample Line Adapter (for SB-2M), Includes Bracket and 1/2” ID Sample Line Clamp
1 GA-100 Umbilical Adapter (Gooseneck), #28 Socket with Thermocouple, Mounting Bracket, 1/2” Male QC
1 NS-SET Set of 7 Stainless Steel Nozzles - Sizes 4,6,8,10,12,14,&16, Includes Case and Four 5/8” tube nuts
1 NG-SET Set of 7 Glass Nozzles - Sizes 4,6,8,10,12,14&16, Includes Case & Three 5/8” Glass Filled PFA
Ferrules
1 GN-DGS Basic Method 5 Glassware Set with Unground Joints & 3” Filter Assembly
1 GF-3TPG 82mm PTFE Coated Glass Fiber Filters - Hydrophobic, Low Absorption of Acid Gases such as SOX,
or NOX, 50/box (MFS PG60)
1 GF-3 3” Glass Fiber Filters, 100/box (Whatman 934AH-82.6mm)
1 PBX-S Modular Probe Brush Extension Kit, Nylon Brushes with Stainless Steel Extensions
1 NB-SET Nozzle Brush Set (sizes 3, 5, & 8) in Carrying Tube
1 P1000-6 Monorail , 6 feet, with Chain, L-Bracket & Hardware
2 P1000-9 Monorail , 9 feet, with Chain, L-Bracket & Hardware
2 P2751 Swivel Frame Trolley with Eye-bolt, 12” Chain & Quick Link
1 TX-XC5 Transport Case, XC500 Series
1 M5CO-SET Calibration Orifice Set, 5 Calibrated Critical Orifices & Spreadsheet Diskette for Method 5
92
It is also recommended to have additional Probe Assemblies to best suit your testing needs. Apex
Instruments, Inc. recommends a 4 foot and 8 foot Probe Assembly in addition to the standard 6 foot which is
included in the above listed system.
Apex Instruments recommended method 17 additional accessories.
Qty Part# Description
3 SFA-2590 Method 17 SS In-Stack Filter Unit
1 GFA-2590 Glass Fiber Thimble, 25X90mm Tapered, 10/box
1 PLS-6S-QCF6 Method 17 6 ft SS Probe Liner with 3/8” Male QC
1 USL-15-QST 15 ft Unheated Sample Line, PTFE with SS Overbraid
1 UA-3J Power Box Adapter, 3 Receptacles
1 SB-8 Sample Frame w/ Probe Clamp & Impinger Box Slides
Apex Instruments recommended method 23 additional accessories.
Qty Part# Description
1 SB-4 Impinger Box / Insulated Coolant Reservoir, Holds 8 Impingers
2 GNM-HC Horizontal Condenser, #28 Socket both ends, Water Jacket Hose Barbs
2 GN-9AKS Knock-Out Impinger Assembly, Unground
8 GNM-T XAD Trap, #28 Unground Socket & O-Ring Ball, Water Jacket Hose Barbs
4 TL-7/5 Surgical Tubing, 3/8 IN (2 FT.)
1 MM5-P220 Submersible Coolant Pump, 220V (120V option)
1 PBC-6 6 ft Extendible Aluminum Probe Brush with PB-5/8 Nylon Brush
1 NTG-10U 5/8” Glass-Filled Teflon Union with Nuts and Ferrules
1 PBT-5/8 Teflon Probe Brush, 5/8” Diameter, 4” Length, 8-32 Thread
1 PBX-8T 8 FT Flexible TFE Probe Brush Extension, Brush Not Included
1 T-TFE24 Teflon Tape, High Density, 1.5” x 520” per roll
1 SB-4 Impinger Box / Insulated Coolant Reservoir, Holds 8 Impingers
93
Apex Instruments recommended method 29 additional accessories.
Qty Part# Description
1 SB-4 Impinger Box / Insulated Coolant Reservoir, Holds 8 Impingers
1 GN-9AK Knock-Out Impinger, Short Stem, 500ml, Unground O-Ring Joints
1 GF-3QH 3” Quartz Fiber Filters, 100/box (MFS QR100 82 mm)
1 PBT-5/8 Teflon Probe Brush, 5/8” Diameter, 4” Length, 8-32 Thread
1 PBX-10T 10 FT Flexible TFE Probe Brush Extension, Brush Not Included
1 NBT-1/2 Nozzle Brush, Teflon, ½”
1 NTG-10U 5/8” Glass-Filled Teflon Union with Nuts and Ferrules
1 T-TFE24 Teflon Tape, High Density, 1.5” x 520” per roll
1 NG-SET Set of 7 Glass Nozzles - Sizes 4,6,8,10,12,14&16, Includes Case & Three 5/8” Glass Filled
PFA Ferrules
Apex Instruments recommended method 201A (PM10) additional accessories.
Qty Part# Description
1 PM2.5-10K PM 2.5/10 Cyclone Kit, Includes PM10 Kit, PM2.5 Cyclone Body, Adapters, Pitot & Case
1 UA-3J Power Box Adapter, Includes 1/2 IN Mounting Clamp and 4 Pin Amphenol to 3 Receptacle
1 MPT-6-421-OFF Extended Pitot Tip for PM10/2.5 Sampling, Tube Diameter 3/8 IN, Length 421mm, Offset
1 GF-47Q 47mm Quartz Fiber Filters, 25/box (Pallflex 47mm).
1 PM2-K PM2.5 Cyclone Set, 12 Nozzles, (PM2-NS), Filter (SFA-47), Cyclone Body, Manual and Case.
94
Recommended Spare Parts for Isokinetic Sampling
Apex Instruments, Inc. recommends stocking the following spare parts:
Qty Part # Description
Console Meter Parts (MC-572)
1 TC-765KF Thermocouple Display, panel mount, LED, 120V/240V
1 M313102A Thermocouple Switch, 7-Channel
1 M-31302K Knob for 7-Channel Selector Switch
1 M-1400 Temperature Controller, analog, Love Model 140EF
2 SSR-330-25 Relay, SSRT, 25A, 120/240V
1 M-CB10A Electrical Circuit Breaker, 10A, 120V, panel-mount
2 M-CB3A Electrical Circuit Breaker, 3A, 120V, panel-mount
1 M-49BK Electrical Receptacle, snap-in, screw-term, 120V
1 AM-MCP Amphenol Connector, MC Panel, pre-wired sub
1 M-SV3131 Solenoid Valve, 3-way, brass, 120V
1 DGM-SK25 Dry Gas Meter, SK-25, Metric
1 QC-BHF4-B Quick Connect, bulkhead, ¼”- ¼” tube, female, brass
1 QC-F8-B Quick Connect, ½”- ½ ” tube, female, brass
1 QC-M6-B Quick Connect, 3/8”- 3/8 ” tube, male, brass
1 QC-BHF6-B Quick Connect, bulkhead, 3/8”- 3/8 ” tube, female, brass
1 M-42210 Dual Column Manometer, inclined vertical
1 QC-MAN-F3 Quick Connect, Manometer, female, 1/8” MNPT, stainless steel
2 QC-MAN-M2 Quick Connect, Manometer, male, 1/4” HB, P/C, PVC
2 M-422DS Manometer Displacer, with knob
1 HC83314SS Cabinet Spring Catch for Meter Console
1 HS83314SS Keeper Latch, short shank for Meter Console
External Pump Parts (E-0523)
1 GP-BL50-2 Mini Lubricator
4 AK731 Gast Vanes, Model E-0523 (4 Required)
1 QC-M6-B Quick Connect, 3/8” – 3/8” tube, male, brass
1 QC-F6-B Quick Connect, 3/8” – 3/8” tube, female, brass
Sample Case Parts (SB-1)
1 AM-SBP Amphenol Connector, SB panel, wired
1 TC-PJK Thermocouple Jack, Type K, panel
1 AM-SB500W Hot Box Heater, 500W, 240V
1 PC-1 Hinged Probe Clamp, stainless steel, (2.54 cm OD probes)
95
96
Recommended Spare Parts for Isokinetic Sampling
(continued)
Qty Part # Description
Umbilical Cable Parts (UC-60)
1 QC-F4-B Quick Connect, ¼” – ¼” tube, female, brass
1 QC-F8-B Quick Connect, ½ ” – ½ ” tube, female, brass
1 QC-M4-B Quick Connect, ¼” – ¼” tube, male, brass
1 QC-M8-B Quick Connect, ½ ” – ½ ” tube, male, brass
4 TC-LPS-K Thermocouple Plug, Type K, cord
4 TC-LJ-K Thermocouple Connector, Type K, female
1 AM3101A Amphenol Body, 4-pin cable
1 AM3106B Amphenol Body, 4-socket, cable
2 AM3057 Amphenol Body, strain relief, cable
10 EXP-20 Expando, 1-1/4 inch 500 black
25 PT24004BK PE Tubing, ¼ inch OD, weathered, black, 1000’ roll
25 PT24004NA PE Tubing, ¼ inch OD, weathered, Natural, 1000’ roll
25 PT24004YW PE Tubing, ¼ inch OD, weathered, yellow, 1000’ roll
General Repair and Supply Parts
50 WK-PP-24S Wire, Thermocouple extension, yellow, feet
25 WK-TT-24 Wire, Thermocouple, Type K, TFE insulation, feet
10 4F-B Ferrule, ¼ inch tube, brass
10 6F-B Ferrule, 3/8 inch tube, brass
10 8F-B Ferrule, ½ inch tube, brass
10 10F-B Ferrule, 5/8 inch tube, brass
1 O-113-DZ Silicone O-ring, 5/8 inch, 12 per pack
3 NTG-10F Single Ferrule, 5/8 inch
1 3M-69 Glass Tape, Scotch 69, ¾”. 66 ft. roll
97
Equipment Checklist
98
Appendix B
Calibration Data Sheets
99
100
101
102
103
104
105
106
107
Appendix C
Stack Testing Field Data Sheets
108
109
110
111
112
113
114
115
116
117
118
Appendix D
Calculation Worksheets
119
FEDERAL REFERENCE METHOD 1
Sample and Velocity Traverses for Stationary Sources Plant __________________________________________ Date _______________________ Location __________________________________________ Test No. _______________________
INPUT PARAMETERS
Sketch of Stack Geometry
Circular Stack:
Interior duct cross-section diameter = _______________ m or ft. Sampling port diameter = _______________ cm or in. Sampling port nipple length = _______________ cm or in. Stack cross-sectional area = _______________ m2 or ft2 Rectangular Stack: Length of stack location (L) = _______________ m or ft. Width of Stack location (W) = _______________ m or ft.
Equivalent diameter WL
LWDe
2 = _______________ m or ft.
Sampling Site: Diameter downstream of disturbance = _______________ m or ft. Diameter upstream of disturbance = _________________ Minimum number of sampling points = _________________ Total sampling time = ______________ min Individual point sampling times = ______________ min
120
Sample and Velocity Traverses for Stationary Sources
(continued) Location of Sampling Points:
CIRCULAR
Sample point number
Circular stack % diameter
Distance from sample port opening, in.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
RECTANGULAR
FEDERAL REFERENCE METHOD 2
121
Determination of Stack Gas Velocity and Volumetric Flow Rate (Type S Pitot Tube)
Plant ______________________________________ Date _________________________ Location ______________________________________ Test No. _________________________
INPUT PARAMETERS
Area of stack (m2) or (ft2) = r2 or (D/2)2 or L x W = As = _________________ Pitot tube coefficient = Cp = _________________ Stack gas temperature (K) = °C + 273° or (°R) = °F + 460° = Ts = _________________ Average of square root of velocity head (mm. H2O)1/2 or (in. H2O)1/2 = (√∆p)avg = _________________ Barometric pressure (mm. Hg) or (in. Hg) = Pbar = _________________ Stack gas static pressure (mm. H2O) or (in. H2O) = Pg = _________________ Absolute stack gas pressure (mm. Hg) or (in. Hg) = Ps = _________________ Note: Ps = Pbar + Pg (mm. H2O)/13.6 or (in. H2O)/13.6 Stack gas moisture (fraction) = Bws = _________________ Stack gas dry molecular weight (g/g-mole) or (lb/lb-mole) = Md = _________________ Stack gas wet molecular weight (g/g-mole) or (lb/lb-mole) = Ms = _________________ Note: Ms = Md (1 – Bws) + 18.0 Bws
CALCULATIONS
vS = Stack gas velocity, m/s or ft/s
ss
avgs
avgppsMP
TxpxCxKv
)()(
xxxxKv ps )( = __________________________m/s or ft/s
Kp = 34.97 (Metric Units) = 85.49 (English Units)
Qa = Volumetric flow rate, acmm or acfm
ssa AxvxQ 60
)()(60 xxQa = _____________________acmm or acfm
Determination of Stack Gas Velocity and Volumetric Flow Rate
(continued)
122
Qd = Dry volumetric flow meter, scmm or scfm
sswsd AxvxBxQ )1(60
xxxQd 160 = ____________________scmm or scfm
Qsd = Volumetric flow rate, dscmm or dscfm
std
s
s
std
sswssdP
Px
T
TxAxvxBxQ )1(60
std
std
sdP
xT
xxxxQ )1(60
= ____________________dscmm or dscfm
123
FEDERAL REFERENCE METHOD 3 Gas Analysis for the Determination of Dry Molecular Weight
Plant ___________________________________________ Date _____________________
Location ____________________________________________ Test No. _____________________
INPUT PARAMETERS
Percent Oxygen (O2) by volume, dry basis = %O2 = ______________________ Percent Carbon Dioxide (CO2) by volume, dry basis = %CO2 = ______________________ Percent Carbon Monoxide (CO) by volume, dry basis = %CO = ______________________ Percent N2 = 100 – (%O2 + %CO2 + %CO) = %N2 = ______________________
CALCULATIONS
Md = Dry molecular weight, g/g-mole or lb/lb-mole
)%(%28.0)(%32.0)(%44.0 222 CONOCOM d
)(28.0)(32.0)(44.0 dM = __________g/g-mole or lb/lb-mole
Ms = Wet molecular weight, g/g-mole or lb/lb-mole
)(0.18)1( wswsds BBMM
)(0.18))(1( sM = __________ g/g-mole or lb/lb-mole
%EA = Excess Air, %
100
)%5.0(%)(%264.0
%5.0)(%%
22
2 xCOON
COOEA
100)5.0()(264.0
5.0)(% xEA
= ______________________________%
124
FEDERAL REFERENCE METHOD 4 Determination of Moisture Content of Stack Gases
Plant _______________________________________________ Date _______________________ Location _______________________________________________ Test No. _______________________
INPUT PARAMETERS
Volume of gas sampled through dry gas meter = Vm = ________________ Dry gas meter (DGM) calibration factor = Y = ________________ Average DGM temperature (K) = °C + 273° or (°R) = °F + 460° = Tm = ________________ Average DGM orifice pressure differential (mm H2O) or (in. H2O) = ∆H = ________________ Volume of water collected, condensed, [Vf - Vi], ml = Vlc = ________________ Volume of water collected in silica gel (W f – Wi), g = Vwsg = ________________ Barometric pressure (mm. Hg.) or (in. Hg) = Pbar = ________________
CALCULATIONS
Vm(std) = Volume of gas sampled at standard conditions, dscm or dscf
m
bar
std
std
mstdmT
HP
xP
TYVV
6.13)(
6.13)(
std
std
stdmP
TV = _____________dscm or dscf
Vwc(std) = Volume of water vapor condensed at standard conditions, scm or scf
ifstdwc VVKV 2)(
2)( KV stdwc = _______________scm or scf
K2 = 0.001333 (Metric Units) 0.04706 (English Units)
125
Determination of Moisture Content of Stack Gases
(continued) Vwsg(std) = Volume of water vapor collected in silica gel
ifstdwsg WWKV 3)(
3)( KV stdwsg = ______________scm or scf
K3 = 0.001333 (Metric Units) 0.04706 (English Units) Bws = Mole fraction of water vapor
)()()(
)()(
stdmstdwsgstdwc
stdwsgstdwc
wsVVV
VVB
wsB = ________________________
%H2O = Percent moisture
wsBxOH 100% 2
xOH 100% 2 = _______________________%
126
FEDERAL REFERENCE METHOD 5 Nozzle Size Selection Worksheet
Note: The most commonly used equation for estimating isokinetic sampling nozzle diameter is the following (assumes that moisture fraction at dry gas meter equals zero.):
avgs
ss
wspm
mmestn
pP
MT
BCT
PQKD
1
1)(
K1 = 0.6071 (Metric Units) = 0.03575 (English Units)
Source Name ________________________________________ Date _______________________ Facility ________________________________________ Calculated by ___________________
INPUT DATA
Barometric Pressure (mm. Hg) or (in. Hg) = Pbar = ________________ Stack Static Pressure (mm. H2O) or (in. H2O) = Pg = ________________ Stack Gas Pressure (mm. Hg) or (in. Hg)
6.13
g
bars
PPP
6.13sP = Ps = ________________
Dry Gas Molecular Weight (g/g-mole) or (lb/lb-mole) = Md = ________________ assume 30.0 for combustion of coal, oil or gas assign 29.0 if mostly air assign 28.0 if mostly purge nitrogen or use preliminary Orsat® or Fyrite® data Stack Gas Moisture (fraction) = Bws = ________________ use preliminary moisture data use wet bulb/dry bulb if < 212°F BE CAREFUL: fraction Bws = %H2O/100 Wet Gas Molecular Weight (g/g-mole) or (lb/lb-mole)
wswsds BBMM 0.181
0.181 sM = Ms = ________________
Stack Gas Temperature (K) or (°R) = Ts = ________________ °C + 273° = K or °F + 460 = °R Pitot Tube Coefficient = Cp = ________________
127
Nozzle Size Selection Worksheet (continued)
Average Velocity Head (mm. H2O) or (in. H2O) = ∆pavg = ________________ v = calculation of inside square root term
avgs
ss
pP
MTv
x
xv = v = ________________
Sampling Flow Rate (cfm or lpm) = Qm = ________________ assume 0.75 cfm assume 21.24 lpm Dry Gas Meter Temperature (K or °R) = Tm = ________________ use ambient temp + 25°F + 460 = °R Dry Gas Meter Pressure (mm Hg or in. Hg) = Pm = ________________ use Pbar + (∆H@)/13.6
CALCULATION OF NOZZLE SIZE
Estimated Nozzle Diameter (mm or inches)
avgs
ss
wspm
mmestn
pP
MT
BCT
PQKD
1
1)(
1
1)(
xx
xxxKD estn = Dn(est) = ________________
K1 = 0.6071 (Metric Units) = 0.03575 (English Units)
Actual Nozzle Diameter Chosen (mm or inches) = Dn = ________________
128
Nozzle Size Selection Worksheet (continued)
K-FACTOR CALCULATION
∆H = Isokinetic Rate Orifice Pressure Differential
pKxH
mss
smd
wspnPTM
PTMBCHDK
p
HK
22
@
4
6 1
224
6 1
K
p
HK = _________________
K6 = 8.038x10-5 (Metric Units) = 846.72 (English Units) CHECK CALCULATIONS FOR SUFFICIENT SAMPLE VOLUME AND ISOKINETIC RATE 90-110%
Stack Gas Velocity (m/s or ft/sec) = vs = ________________ from preliminary velocity run convert to m/min or ft/min vs x 60 sec/min = vs(fpm) or(mpm) = ________________ Estimated Sampling Time (minutes) = θ = ________________
multiply number of traverse points by minutes/point = _________total min.
CALCULATION OF ACTUAL SAMPLING RATE
Qm(std) = Actual Sampling Rate (dscmm or dscfm)
s
nmpmorfpmssws
stdmT
DvPBQ
1039
1100 2
)()(
)(
1039
11002
)(
stdmQ = ________________
Vm(std) = Total Gas Sample Volume to be Collected (dscm or dscf)
xQV stdmstdm )()( = ________________
Based on applicable regulations for this source: Will there be sufficient sample volume (dscf)? yes no Will there be sufficient sampling time (minutes)? yes no
129
Nozzle Size Selection Worksheet (continued)
Check Intermediate Isokinetic Sampling Rate
wsnss
stdms
wssnsstd
stdstdms
iBAvP
VTK
BPAvT
PVT
1160
100I%
)(4)(
1
I% 4Ki = ________________
K4 = 4.320 (Metric Units)
= 0.09450 (English Units) Check Final Isokinetic Sampling Rate
An = Nozzle Area 2
4nD
= __________in2 or mm2
nsavgs
bar
avgm
totm
lcavgs
APv
HP
T
VVKT
)(
)(
)(
3)(
f60
6.13100
I%
60
6.13100
I%
3
f
K
= ________________
K3 = 0.003454 (Metric Units) = 0.002669 (English Units)