Dewpoint transmitter to -45 °Ctd

SPECIFICATIONStesto 6740

SPECIFICATIONStesto 6740

testo 6740

The testo 6740 was especilally developed for tracehumidity measurement in compressed or dry air (e.g. granulate dryers). Thanks to a special adjustment,optimum accuracy in the trace humidity range hasbeen achieved. The result of the development of thetesto 6740 is a measuring range of -45 °Ctd to+30 °Ctd and excellent accuracy.

For the display of the relevant trace humidityparameters, a freely scalable analog output isavailable, optionally with a switch contact plug forMAX monitoring. In addition to this, the testo 6740stands out thanks to its compact and user-friendlydesign, such as the rotatability of the housing by350° for the optimum positioning of the display.

Areas of application:

• Refrigeration dryers

• Membrane dryerser

• Adsorption dryers

• Granulate dryers

• Measurement of dewpoints in the range from-45 °Ctd to +30 °Ctd

• Testo polymer humidity sensor with high accuracyand long-term stability

• Convenient operation via the display menu

• Analog output 4 to 20 mA (2-wire) and optionalalarm plug with 2 integrated switch outputs

• Compact design with rotatable housing by 350° foroptimum positioning of display

• Display with operating menu (optional)

• Trace humidity adjustment without referencemeasuring instrumentpossible on site with accessory (2-pointadjustment device), replaces expensive adjustmentwith dewpoint mirror

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testo 6740

Subject to change without notice.

Dewpoint transmitter to -45 °Ctd

Technical data

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Supply

Analog outputs

Switch outputs (opt. alarm plug, 0554 3302)

Resolution 12 bit

Current/accuracy 4 to 20 mA (2-wire) / ±40 μA

load 10 V DC: max. 100 �,30 V DC: 950 �

Inputs and outputs

Measurement rate 2 s

Contacts 2 closer contacts, pot.-free, max.30V/0.05A

Voltage supply 24 V AC/V DC (10 to 30 V DCpermitted); with alarm plug (0554 3302)20 to 28 V DC

Display

Design

Installation

General technical data

Material/colour Plastic, polyacrylamide

Dimensions 199.5 x 37 x 37 mm(with standard plug)203.5 x 37 x 37 mm(with plug 0554 3302)

Display

Protection class IP65 (with plug attached and wireconnected

EMC According to guideline 89/336 EEC

Thread / processconnection

G½ thread (order code 01) or NPT½"thread (order code A 02)

Weight Approx. 300 g

High intensity 7-segement display

Operating temperature(housing)

-20 to +70 °C (+4 to +158 °F)

Operating conditions

Storage temperature -40 to +80 °C (-40 to +176 °F)

Dewpoint/trace humdity

Measurement parameters

Calculated parameters °Ctd, °Ftd, °CtA, °FtA, ppmv, mg/m3, °F

Units %RH, °C

Response time t90 �= 60 sec for change from 13.2°Ctd to -32.1 °Ctd

t90 �= 17sec for change from -32.2°Ctd to 13 °Ctd

Measurementuncertainty

±1 K at 0 °Ctd (+32 °Ftd)±3 K at -20 °Ctd (-4 °Ftd)±4 K at -40 °Ctd (-40 °Ftd)

Normed atmospheric dewpoint

Measuring range -70 to -15 °CtdA (-112 to -5 °FtdA) (at30 bar rel./ 435 psi)-54 to +10 °CtdA (-94 to +50 °FtdA) (at3 bar rel./43.5 psi)-45 to +30° CtdA (-76 to +86 °FtdA) (at0 bar rel./0 psi)

Sensor Polymer humidity sensor withprotocolized trace humidity adjustmentat -40 °Ctd (-40 °Ftd)

Miscellaneous

Process pressure max. 50 bar (725 psi)

Measuring range -45 °Ctd to +30 °Ctd

TemperatureMeasuring range 0 to 50 °C (32 to +122 °F)

Measurement uncertainty ±0,5K (0 to 50 °C/32 to 122 °F)

Sensor NTC

Scaling Freely scalable via display buttons

Switch thresholds Standard 6 °Ctd/12 °Ctd, freely progr.with display

Current consumption 21 mA (without alarm plug)65 mA (with alarm plug)

Resolution °C: 0.1RH: 0.1°Ctd: 0.1°Ftd: 0.1°CtA: 0.1°FtA: 0.1

Rotatability (displaypositioning)

350° around housisng axis

ppmv: 1 / 10 / 100(dep. on meas. value)mg/m3: 1 / 10 / 100(dep. on meas. value)°F: 0.1

We measure it.

testo 6740

Dewpoint transmitter to -45 °Ctd

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Technical drawings

G½

or

NP

T½

SW

2737 Ø 1

2

Installation depthin process

33 40 108.5

181.5 10 34

38

56

38.9

51 71

176

Standard connection plug (4 to 20 mA – 2-wire)

Switch contact plug: cable connection plug forsupply/analog output (4 to 20 mA – 2-wire)

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testo 6740

Order data testo 6740

testo 6741, G½ thread, without display 0555 6741testo 6742, NPT½ thread, without display 0555 6742testo 6743, G½ thread, with display 0555 6743testo 6744, NPT½” thread, with display 0555 6744

Order no.Basic instrument (incl. plug for analog signal output)

Pin plugterminals

Relay boardterminals

U = 20 to28 V DC

US (main alarm)

LS (pre-alarm)

PE

4 to 20 mA

Supply

Dewpoint transmitter to -45 °Ctd

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Connection plan

With standard plug (included in delivery 0555 674x): With switch contact plug (0554 3302)

Pin plug terminals1: + (4 to 20 mA), Supply 12 to 30 VDC2: - (4 to 20 mA)3: Not used4: Measurement earth (cable shield)

Relais board wire (connected ex-works)

Shield on PE(protectionearth)

Pin plug terminals1: I + (4 to 20 mA)2: I - (4 to 20 mA)3: (connected with

relay board ex-works)

: Connect shield

Relay board terminals1: 20 to 28 V DC2: LS +3: LS -4: US +5: US -6: 0 V DC

Current signaland supply 20 to28 V DC

Pin plug

Rel

ay b

oard

Standard plug

This version provides a 4 to 20 mA analog output in 2-wire technology.

Switch contact plug (0554 3302)

4 to 20 mA, 2-wire as well as 2 potential-free switch contacts + 2 LED

Max. switching 0.5 A/30 V

4

1

+

The supply connections must be galvaicallyconnected, i. e. make connection - or - !

U = 10 ...4 to 20 mA

We measure it.

Dewpoint transmitter to -90 °Ctd

SPECIFICATIONStesto 6781

SPECIFICATIONStesto 6781

testo 6781

The transmitter testo 6781 was developed speciallyfor trace humidity measurement in compressed airand in dry air (e. g. in granulate dryers). Theinternational norm ISO 8573 categorizes sevenclasses of compressed air. High-performanceadsorption dryers are required in order to meet thehighest quality classes 1 and 2. They can bemonitored by the testo 6781 down to very lowdewpoints of -90 °Ctd.

The newly developed sensor with sol-gel technologyis characterized by its condensation-proofness andfast response time, thus guaranteeing highestprocess security.

Areas of application:

• Dewpoint measurement in compressed air in ISOClasses 1 (�-70 °Ctd) and 2 (�-40 °Ctd)

• Monitoring of adsorption dryers, granulate dryersand medical compressed air

• Quality assurance for noble gas preparation

• Measurement of dewpoints in the measuringrange -90 to -20 °Ctd

• New, very condensation-proof sensor with sol-geltechnology guarantees highest process securityand fast response

• Automatic self-adjustment ensures high accuracyand long reliability

• Optional display with multi-language user menu

• Self-monitoring of the transmitter guarantees highsystem availability

• The P2A software for parameterization,adjustment and analysis saves time and costs incommissioning and maintenance 0981

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testo 6781

Supply

Analog outputs

Other outputs

Resolution 12 bit

Load max. 500 �

Meas. cycle 1/sec

Inputs/outputs

Current/accuracy 0 to 20 mA ±0.03 mA (4-wire)4 to 20 mA ± 0.03 mA (4-wire)

Output type 0 to 1 V ±1.5 mV (4-wire)0 to 5 V ± 7.5 mV (4-wire)0 to 10 V ±15 mV (4-wire)

Digital Mini-DIN for P2A software

Voltage supply

The determination of measurement uncertainty takes place according to GUM(Guide to the Expression of Uncertainty in Measurement):For the determination of measurement uncertainty, the accuracy of themeasuring instrument (hysteresis, linearity, reproduceability), the uncertaintycontribution of the test site as well as the uncertainty of the adjustment site/works calibration are taken into account. For this purpose, the value of k=2 ofthe extension factor, which is usual in measurement technology is used as abasis, which corresponds to a trust level of 95%.

This total view results in an additional dewpoint-dependent and process-dependent inaccuracy contribution of±0,03K x m.v.(in °Ctd) + 0.2 K x (25 °C - process temperature in °C).

Below -75 to -90°Ctd, an assymetrical measurement uncertainty of +8.5 K / -2.5K applies.

Display

Model

Miscellaneous

Display optional: 2-line LCD with multi-language operating menu

General technical data

Material Metal housing

Dimensions 208 x 60 x 35 mm

Weight 0.5 kg

Resolution

Protection class IP 65

EMC EU guideline 2004/108/EC

Measuring range Resolution

0 to +100 %RH 0.0010.001 to 28 g/kg 0.0010.01 to 194 g/lb 0.010 to 31 g/m3 0.0010.001 to 14 g/ft3 0.0010.1 to 9999 ppm(V) 0.1-90 to -20 °Ctd 0.1-130 to -4 °Ftd 0.1-90 to -20 °CtdA 0.1-130 to -4 °FtdA 0.1-40 to +70 °C 0.01-40 to +158 °F 0.01

Technical data

Subject to change without notice.

Dewpoint transmitter to -90 °Ctd

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Operation temperatureWithoutdisplay

With display

-40 to +70 °C / -40 to +158 °F

Storage temperature -40 to +80 °C / -40 to +176 °F

Operation temperature -20 to +70 °C / -4 to +158 °F

Storage temperature -20 to +70 °C / -4 to +158 °F

Process temperature -40 to +70 °C / -40 to +158 °F

Process pressure max. 50 bar

Operating conditionsOperating conditions

Humidity/trace humidity

Parameters

Measuring range -90 to -20 °Ctd / -130 to -4 °Ftd

Measurementuncertainty*

-20 °Ctd to -40 °Ctd: ±1,5K-40 °Ctd to -60 °Ctd: ±2K-60 °Ctd to -75 °Ctd: ±2,5K

Response time t63 ≤ 3s for switch from -75 °Ctd to -30°Ctd

t90 ≤ 9s for switch from -75 °Ctd to -30°Ctd

t63 ≤ 300s for switch from -30 °Ctd to -75 °Ctd

t90 ≤ 1080s for switch from -30 °Ctd to-75 °Ctd

Autom. self-adjustment Cycle adjustable: 1 h / 6 h / 12 h / 24 h / 48 h

Units °Ctd, °Ftd, %rF, %RH

Calculated variables °CtdA, °FtdA (normed atmosph. dewpoint),ppmV, g/m³, g/ft³, g/kg, g/lb

20 to 30 VAC/DC, 300 mA currentconsumption, galvanically separatesignal and supply linePlug connection: M12 5-pin plug**

** Suitable M12 socket available as accessory

We measure it.

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testo 6781

Dewpoint transmitter to -90 °Ctd

Subject to change without notice.

Technical drawings

Connection plan

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208 mm

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77 m

m35 m

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Connection plan 4-wire technology(0 to 20 mA/4 to 20 mA/0 to 1 V/0 to 5 V/0 to 10 V)

Plug connection M12 (5-pin), plug

Pin Connection

1

2

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-24 V

+24 V

+Ch1

-Ch1

PE

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testo 6781

Dewpoint transmitter to -90 °Ctd

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The following options can be specified for the testo 6781:

AXX Process connection

BXX Analog display/supply

CXX Display / menu language

FXX Humidity parameter / min limit value / maxlimit value / hysteresis (pre-set)

MXX Protective cap

AXX Measuring range

A01 Process connection G1/2A02 Process connection NPT 1/2“

BXX Analog display/supply

B02 0 to 1 V (4-wire, 24 VAC/DC)*B03 0 to 5 V (4-wire, 24 VAC/DC)*B04 0 to 10 V (4-wire, 24 VAC/DC)*B05 0 to 20 mA (4-wire, 24 VAC/DC)*B06 4 to 20 mA (4-wire, 24 VAC/DC)*

CXX Display / menu language

C00 without displayC02 with display/EnglishC03 with display/GermanC04 with display/FrenchC05 with display/SpanishC06 with display/ItalianC07 with display/JapaneseC08 with display/Swedish

FXX Humidity parameter / min limit value / maxlimit value / hysteresis (pre-set)

F01 °Ctd / min / maxF02 °Ftd / min / maxF03 % RH/Min/MaxF04 %RH / min / maxF05 °Ctd A / min / maxF06 °Ftd A / min / maxF07 ppmV / min / maxF08 g/m³ / min / maxF09 g/ft³ / min / maxF10 g/kg / min / maxF11 g/lb / min / max

MXX Protective cap

M01 Stainless steel capM03 PTFE cap

Order code for transmitter testo 6781 withthe following options:

- Process connection NPT 1/2“- Analog display/supply 4 to 20 mA (4-wire,

24 VAC/DC)- without display- Humidity parameter / min limit value / max

limit value / hysteresis g/m³ / min / max- Sintered stainless steel cap

Example:

0555 6781 A02 B06 C00 F08 M01

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Dewpoint guard to -30 °Ctd

SPECIFICATIONStesto 6721

SPECIFICATIONStesto 6721

testo 6721

The testo 6721 is a budget dewpoint guard withswitch contacts.

Continuously monitoring a "simple" compressed airrefrigeration dryer was often not economically viablein the past. This security gap is now closed with thetesto 6721. Whether integrated into the refrigerationdryer or pneumatic machine, or retrofitted by thecustomer, the testo 6721 avoids damage caused byexcessive humidity in compressed air.

Areas of application:

Since the testo 6721 has only aswitch output, it isprimarily suited to monitoring limit values.measurement values cannot be output via an analogsignal. The budget monitoring function is particularlysuitable at machine level, in order to protect asystem, e. g. compressed air refrigeration dryers,from humidity damage. This avoids costly repairwork necessary by high humidity, leading to icing,corrosion, material adhesion, "water hammer"(mechanical damage due to accelerated waterdeposits), and much more.

• Measurement of dewpoints in themeasuring range -30 to +30 °Ctd

• 2 switch outputs as output for monitoring limitvalues

• long term stable and condenstation-proof Testohumidity sensor (polymer sensor) guaranteeshighest process security

• P2A software for parameterization, adjustment andanalysissaves time and costs in commissioningand maintenance

• Low-budget solution for monitoring refrigerationdryers

• Compact design allows easy integratiion into arefrigeration dryer or pneumatic machine

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testo 6721

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Dewpoint guard to -30 °Ctd

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Power

Outputs

Further outputs

Measurement rate 1/s

Switch outputs 2 x potential-free, switch voltage 24VDC / VAC, switch current 0.5 A,optional wiring as NC contact or NOcontact

Resolution switch output 0.1 °Ctd or 0.1 °Ftd

Inputs and outputs

Hysteresis and limitvalues

Free selection within measurementrange through Order code, or set usingP2A software

Digital Mini DIN interface (serial) forparameterisation/adjustment/analysisthrough P2A software

Voltage supply 24 VAC / VDC (20 to 30 VAC / VDCmax.)

Technical data testo 6721

Current consumption

AC or DC

Design

Installation

General technical data

Material Plastic PAA GF30

Dimensions 167 x 33 x 33 mm

Protection class IP65

EMC In accordance with EU guideline89/336/EEC

Thread / process connection

G½ thread (Order code A01) or NPT½“thread (Order code A02)

Weight 240 g

Operating temperature(housing)

0 to +50 °C (32 to +122 °F)

Operating conditions

Storage temperature -40 to +70 °C (-40 to +158 °F)

Dewpoint/trace humidity

Parameters

Meas. range -30 to +30 °Ctd (-22 to +86 °Ftd)

Units °Ctd / °Ftd

Reaction time �= 1s

Measurement inaccuracy ±4 K > -30 °Ctd (-22 °Ftd)±3 K > -20 °Ctd (-4 °Ftd) ±2 K > -10 °Ctd (+14 °Ftd) ±1 K > 0 °Ctd (32 °Ftd)

Sensor protection Stainless steel sintered filter (12 mm)

Temperature

Sensor NTC

Sensor Testo humidity sensor with specialtrace humidity adjustment (polymersensor)

Outputs

2-wire current4 to 20mA

4-wire voltage

DC

DC

AC

Supplyvoltage [V]

Currnetconsumption [mA]

20 / 24 / 30 20 / 20 / 20

24 / 30 / 20 7 / 7 / 20

24 / 30 22 / 28

Other features

Measuring medium Compressed air (filtered and dried,ISO 8573-classes 2-4-2)

Process pressure max. 20 bar (abs.)

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testo 6721

Dewpoint guard to -30 °Ctd

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Technical drawings

Connection plan

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9242

Pin allocation1 Root switch contact 12 Closer switch contact 13 Opener switch contact 14 Supply +5 Opener switch contact 26 Closer switch contact 27 Function earth8 Supply -9 Root switch contact 2

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testo 6721

Dewpoint guard to -30 °Ctd

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The following options can be specified for the testo 6721:

AXX Process connection

FXX Unit dewpoint / min. max. limit value /hysteresis (pre-setting)

AXX Process connection

A01 Process connection G½A02 Process connection NPT ½"

FXX Unit dewpoint / min. max. limit value /hysteresis (pre-setting)

F01 Dewpoint °Ctd / LV 1 / LV2 / hysteresisF02 Dewpoint °Ftd / LV 1 / LV2 / hysteresis

Order code for testo 6721 with thefollowing options:

- G½ thread- Dewpoint in °Ctd

- Lower limit value at 5 °Ctd

- Upper limit value at 14 °Ctd

- Hysteresis = 1 K

Example:

0555 6721 A01 F01 5 14 1

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Limit values: Without specification, default limit values are +5 °Ctd /+10 °Ctd, at 1 Kelvin hysteresis (for unit °F: 45 °Ftd / 55 °Ftd / 2 °Fhysteresis). They can be set to customer requirements with the helpof the Order code, cf. Order example.

We measure it.