Sales / Design Presentation. Topics Aspirating Smoke Detection – What it is Fixed Vs Relative...

Sales / Design Presentation

TopicsTopicsAspirating Smoke Detection

– What it is

Fixed Vs Relative Sensitivity Systems– How do they compare?– ClassiFire®

Design Considerations– The 5 Design Methods– Sampling Pipe Design– Choice of Detector type

Aspirating Smoke DetectionAspirating Smoke Detection

A method of smoke detection, whereby a sample of air is drawn from the protected area via sampling pipework, and analysed at the aspirating detector for the presence of smoke.

Historically used for very early warning of a potential fire, within very well controlled environments. ClassiFire® makes it possible for Aspirating Smoke Detection to be utilised in a much wider range of applications.

Pipe Inlets

Air Plenum

Aspirating Fan

Separator/Filter

Detection ChamberLaser

Exhaust

OverviewOverview

Air from the protected

area is drawn along the Sampling Pipe by an

efficient Aspirator

AirflowAirflow

Passing over sensitive air-

flow measuring sensors.

Each Pipe is monitored separately

AirflowAirflow

Of all the air which is drawn into the

detector assembly….

Only a small proportion (~5%)

passes through the separator into the detection chamber

AirflowAirflow

The remainder passes through a

patented duct system called a Wastegate, and is exhausted out of

the detector

The Wastegate extends the life of the Separator and

Detector considerably

AirflowAirflow

Light Receiver

Any Smoke particulate entering the chamber will be illuminated by

the laser

DetectionDetection

And Light will be scattered onto the reflective plane, re-focussed onto the light

receiver

The quantity of light scattered increases with greater

quantities of smoke particulate present

Fixed v Relative SensitivityFixed v Relative Sensitivity

Stratos-HSSD® is the only Relative Sensitivity Aspirating Detection system available

All other systems have the sensitivity (the amount of smoke required to produce an alarm) fixed during manufacture

The sensitivity of Stratos-HSSD® is determined by the ambient smoke level of the protected area

Pre-Fire

Fire

Calibrated to0.1% obs/m

0.08% obs/m

0.06% obs/m

Calibrated to0% obs/m (Clean Air)

Sensitivity is Fixed, Compared to 0% obs/m Ambient

As Smoke enters the detector via a network of sampling pipe, the display graph will register the increasing smoke levels, triggering relay outputs as the level passes each pre-set threshold

The alarm thresholds are in fact a measurement of smoke density, regardless of whether ambient or produced by a developing fire

Fixed SensitivityFixed Sensitivity

Pre-Fire

Fire

0.1% obs/m

0.08% obs/m

0.06% obs/m

0% obs/m

0.03% obs/m

0.05% obs/m

0.07% obs/m

However, if the ambient smoke level is not zero (clean air), then the actual sensitivity to smoke produced by a fire will vary

Ambient0.03% obs/m

If the ambient level fluctuates, then the sensitivity to a fire will also fluctuate

Additional smoke required to generate an alarm


Pre-Fire

Fire

0.1% obs/m

0.08% obs/m

0.06% obs/m

0% obs/m

0.02% obs/m

0.04% obs/m

0.06% obs/m

Ambient0.04% obs/mIf the ambient level rises, the sensitivity increases, and with it the potential for false alarms occurring


Pre-Fire

Fire

0.1% obs/m

0.08% obs/m

0.06% obs/m

0% obs/m

0.05% obs/m

0.07% obs/m

0.09% obs/m

Ambient0.01% obs/m

If the ambient level falls, the sensitivity decreases, and therefore you will have reduced protection



Time

Sm

oke

De

nsi

ty

Fixed Sensitivity

Variable Ambient Smoke Level

The Sensitivity Level must be set above

the highest ambient level if false alarms are to be avoided

The Sensitivity to a Fire varies with changing

ambient smoke levels

Variable SensitivityVariable Sensitivity(relative scaling)(relative scaling)

Time

Sm

oke

De

nsi

ty

Fixed Sensitivity

Variable Ambient Smoke Level

Because Stratos-HSSD is a RELATIVELY scaled (sensitivity) detector, the sensitivity to

a FIRE remains constant, regardless of changing ambient conditions

Fixed Sensitivity SystemsFixed Sensitivity SystemsProblemsProblems

Calibrated to a known smoke density value– Sensitivity to a FIRE varies with changing ambient

conditions Greater Sensitivity = More False Alarms Less Sensitivity = Low level of Protection

Fixed Alarm Levels– Must be manually altered, and are constantly “out

of date”

Comparison of Fixed and Comparison of Fixed and Variable Sensitivity DetectorsVariable Sensitivity Detectors

Will Alarm at a fixed smoke density level, regardless of whether smoke is ambient or produced by a fire

The sensitivity to a Fire varies with changing ambient conditions

ClassiFire sets the correct level of sensitivity, based upon the ambient smoke level

ClassiFire maintains that sensitivity regardless of changes in ambient conditions

Fixed Sensitivity Variable Sensitivity

What is ClassiFireWhat is ClassiFire

A patented “Artificial Intelligence” process controlling all aspects of the system, ensuring the maximum safe sensitivity - regardless of ambient conditions


Detector Output (smoke density) 0%

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Real Time ClassiFire Viewer Detector: 001

Alarm Factor: 4

Fire 1 Level: 0.00%

Fire 2 Level: 0.00%

Pre-Alarm Level: 0.00%

Aux Level: 0.00%

Sensitivity: 0.00% obs/m

Mean: 0.00%

Variance: 0.00%

FastLearn: ON: 15

Day/Night: Day

5%4%5%6%5%4%5%

During an initial FastLearn process, the detector samples the environment once each second, and produces a histogram representing the ambient pollution (smoke) level

This Histogram fits a Standard Deviation Curve, allowing statistical analysis of the data

Mean

Variance

+ 1SD > 68%

+ 2SD > 95%

+ 3SD > 99%

The probability of a normal event occurring outside of + 3 SD is extremely remote. Particularly since events to the left of the curve are not relevant from a False Alarm Point of View

ClassiFire uses this information to automatically set the correct sensitivity and alarm thresholds, determined by an acceptable frequency of False Alarms

Any normal curve can be divided into 3 equal width strips called a Standard Deviation, with a known probability of a random event falling into each category

Statistical ProbabilityStatistical Probability

5’10”5’8”5’6”5’4” 6’2”6’0” 6’4”

Detector Output 0%

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Alarm Factor: 4

Fire 1 Level: 0.00%

Fire 2 Level: 0.00%


Aux Level: 0.00%


Mean: 0.00%

Variance: 0.00%

FastLearn: ON: 15

Day/Night: Day

5%4%5%6%5%4%5%

After the 15 minute Fastlearn process, a slow updating histogram takes over

Alarm

The Alarm Position is initially set well out of the way (Low Sensitivity)


And ClassiFire continues to update the histogram for the entire lifetime of the detector

Detector Output 0%

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Alarm Factor: 4

Fire 1 Level: 0.00%

Fire 2 Level: 0.00%


Aux Level: 0.00%


Mean: 0.00%

Variance: 0.00%

FastLearn: ON: 15

Day/Night: Day

5%4%5%6%5%4%5%


After 24 hours, ClassiFire has sufficient data to set the alarm position at its best Safe sensitivity…..

n x SDAlarm

Based upon the statistical Probability of Nuisance Alarms

n = Alarm Factor0 - 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8

Environment

Setting the ScaleSetting the Scale

Detector Output 0%

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Alarm Factor: 4

Fire 1 Level: 0.00%

Fire 2 Level: 0.00%


Aux Level: 0.00%


Mean: 0.00%

Variance: 0.00%

FastLearn: ON: 15

Day/Night: Day

5%4%5%6%5%4%5%

Alarm

1 2 3 4 5 6 7 8 9 10 Stratos-HSSD Scale

Position 8 on the scale is fixed to where ClassiFire has placed the Alarm Position

Zero is fixed on the Mean

And the Sensitivity and Scale is therefore unique to the particular protected area

Detector Output 0%

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Alarm Factor: 4

Fire 1 Level: 0.00%

Fire 2 Level: 0.00%


Aux Level: 0.00%


Mean: 0.00%

Variance: 0.00%

FastLearn: ON: 15

Day/Night: Day

5%4%5%6%5%4%5%

Alarm

1 2 3 4 5 6 7 8 9 10 Stratos-HSSD Scale


Only smoke density levels which are above the mean are displayed on the bargraph of Stratos-HSSD

So the usual fluctuations in bargraph display (as seen on Fixed Sensitivity systems) do not occur

1 2 3 4 5 6 7 8 9 10 Fixed Scale Detectors1 2 3 4 5555

Detector Output 0%

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Alarm Factor: 4

Fire 1 Level: 0.00%

Fire 2 Level: 0.00%


Aux Level: 0.00%


Mean: 0.00%

Variance: 0.00%

FastLearn: ON: 15

Day/Night: Day

5%4%5%6%5%4%5%


Alarm

1 2 3 4 5 6 7 8 910 Stratos Scale

n x SD

In a cleaner environment, the mean will tend to be at a lower value, and the variance (and therefore the SD value) will be less The Alarm position will still be

placed a set number of standard deviations from the mean, determined by the Alarm Factor ‘n’

And therefore the detector will statistically have the same frequency of False alarms as in a dirtier environment

The same rules apply to the scale

2%

Reacting to a FireReacting to a Fire

Detector Output 0%

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Alarm Factor: 4

Fire 1 Level: 0.00%

Fire 2 Level: 0.00%


Aux Level: 0.00%


Mean: 0.00%

Variance: 0.00%

FastLearn: ON: 15

Day/Night: Day

5%4%5%6%5%4%5%

Alarm

1 2 3 4 5 6 7 8 9 10

The slow updating histogram determines the sensitivity and the scale

But the Fast updating histogram is still operating, updating once per second As the smoke level begins to rise,

the fast updating histogram will register this increase, and display the rising smoke level on the bargraph

1 2 3 4 5 6 7 8 9

6%7%8%9%10%18%

Detector Output 0%

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req

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Alarm Factor: 4

Fire 1 Level: 0.00%

Fire 2 Level: 0.00%


Aux Level: 0.00%


Mean: 0.00%

Variance: 0.00%

FastLearn: ON: 15

Day/Night: Day

5%4%5%6%5%4%5%

Day/Night ModeDay/Night Mode

So far we have only considered the slow updating histogram as a 24 hour entity

If we examine a 24 hour period, and separate it into two 12 hour periods, we will probably see two distinctly different histogramsDaytimeNight-time

The Night-time histogram probably has a lower mean value, and a smaller deviation. This is because smoke producing activity lessons during the night in most premisesBoth histograms require different levels of sensitivity, based upon the same formula n x SD

Detector Output 0%

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Alarm Factor: 4

Fire 1 Level: 0.00%

Fire 2 Level: 0.00%


Aux Level: 0.00%


Mean: 0.00%

Variance: 0.00%

FastLearn: ON: 15

Day/Night: Day

5%4%5%6%5%4%5%

During the daytime, ClassiFire maintains the sensitivity according to n x SD

Alarm

Last night’s histogram is stored in memory

The fast updating histogram is always operating in the background



Detector Output 0%

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Alarm Factor: 4

Fire 1 Level: 0.00%

Fire 2 Level: 0.00%


Aux Level: 0.00%


Mean: 0.00%

Variance: 0.00%

FastLearn: ON: 15

Day/Night: Day

5%4%5%6%5%4%5%

Alarm

As night-time approaches, we expect to see a reduction in smoke level, resulting in the fast updating histogram shifting to the left


Detector Output 0%

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Alarm Factor: 4

Fire 1 Level: 0.00%

Fire 2 Level: 0.00%


Aux Level: 0.00%


Mean: 0.00%

Variance: 0.00%

FastLearn: ON: 15

Day/Night: Day

5%4%5%6%5%4%5%

Alarm

When the fast updating histogram reaches 2/3 of the way to last night’s histogram, ClassiFire checks that the time is within the 70 minute window for status changeover

If both conditions exist (smoke reduction and time frame) …….


Detector Output 0%

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Alarm Factor: 4

Fire 1 Level: 0.00%

Fire 2 Level: 0.00%


Aux Level: 0.00%


Mean: 0.00%

Variance: 0.00%

FastLearn: ON: 15

Day/Night: Night

5%4%5%6%5%4%5%

Alarm

ClassiFire changes status from Daytime to Night-time mode

The next morning the same process happens in reverse

If either of the conditions do not exist (i.e. smoke level not rising on a weekend), ClassiFire will maintain the existing mode

Separator MonitoringSeparator Monitoring

Detector Output 0%

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Alarm Factor: 4

Fire 1 Level: 0.00%

Fire 2 Level: 0.00%


Aux Level: 0.00%


Mean: 0.00%

Variance: 0.00%

FastLearn: ON: 15

Day/Night: Day

5%4%5%6%5%4%5%

As the separator becomes blocked, fewer particles will pass through it, and the slow updating histogram will slowly shift towards the leftAlarmAlarm

ClassiFire continually compensates for this, until a separator renewal fault is required

ClassiFire® is a patented ‘Perceptive Artificial Intelligence’ process which ensures optimal detector performance at all times.

– A ‘FastLearn’ system quickly sets the alarm level to an initial low sensitivity.

– The histogram generated by FastLearn is used as ‘seed data’ for the standard histograms, which tailor the alarm setting to the operating environment during working and non-working hours.

SummarySummary

ClassiFire® can optimise the detector to the way you work

– It can maximise protection during non-operating periods

– It can minimise unwanted alarms during working hours

– Change of sensitivity can be remotely or automatically triggered

– ClassiFire® continually monitors its environment in order to fine-tune the alarm setting to optimum

SummarySummary

SummarySummary

ClassiFire® is simple to set up – An absolute minimum of installer programming is

necessary.– A user-definable Pre-Alarm level can be set to generate

a warning in the earliest stages of a possible fire if required.

– A user definable Auxiliary level can be set to give an alarm event at any level, e.g. if specialist actions are needed in the case of sudden, intense fires.

– Pre-set ClassiFire® alarm factors help to tailor the detector response to your needs and working environment.

SummarySummary

ClassiFire Provides and Maintains the optimum

Sensitivity for the Protected Area, NOT the Maximum

Sensitivity Possible

DesignDesign

The 5 Design MethodsThe 5 Design Methods1. Primary Sampling

The 5 Design MethodsThe 5 Design Methods2. Secondary Sampling

Maximum 2000 m²

The 5 Design MethodsThe 5 Design Methods3. Localised Sampling

The 5 Design MethodsThe 5 Design Methods4. In-Cabinet Sampling

The 5 Design MethodsThe 5 Design Methods5. Vertical Sampling

25º

40º

25º

1000º

Smoke Cools and Dissipates

Smoke Stratifies at Thermal Equilibrium Level

Glass Roof

Stratos™ Detector

The Pipework Modelling Software for Stratos-HSSD products

Limitations The transport time quoted is only within

sampling pipe. Careful consideration must also be given to the time it takes for smoke to reach the pipework

To be used for guidance purposes only. There is no substitute for on site testing

calculation only as good as the information received

PipeCADPipeCAD®®

The process for modelling a basic pipework system design is as follows

The Design CyclePipeCADPipeCAD®®

1. Enter the Snap Grid

2. View the “Whole Page”

3. Select the View

4. Add the Building Outline

5. Add the Detector

6. Add the Pipes

7. Add End Caps, Sampling Holes &Capillaries

8. Calculation Options

9. Calculate

10. View Results

11. What do the Results Mean?

12. Other Features

Import DXF files Create PipeCAD layouts in 3D

format Add labels to a drawing Customization of PipeCAD

13. Help Me!

Comprehensive help file

Helpline: +44 (0)1462 440666

Fax: +44 (0)1462 440888

E-mail your query and file to: [email protected]

Detector Applications

Choosing the right detector for the job

Stratos-HSSD

4 Sampling Ports Available (plus 4 rear entry)

– Single area (Not known which pipe smoke is drawing smoke)

Total Pipe Length 200m

– No individual pipe to exceed 50m

4 Outputs for Fire Signals plus Common Fault

Stratos-HSSD

Requires 24V 1.4 Amp Power Supply / Charger

Requires 2 x 12V 12Ah Batteries

(for 24 hour operation in the event of a Power failure)

Stratos-Micra 25

Single Pipe Detector for Local Applications

Maximum Pipe Length 50m

– No Individual Pipe to Exceed 50m

1 Fire Output plus Common Fault

– Can be fitted with a Relay Card to give 4 Fire

plus common Fault

Requires 24V 1 Amp Power Supply / Charger

Requires 2 x 12V 7Ah Batteries (for 24 hour operation

in the event of a Power failure

Stratos-Micra 25

Stratos-Micra 100

Two Pipe Detector for Larger Applications

Maximum Pipe Length 100m

1 Fire Output plus Common Fault

– Can be fitted with a Relay Card to give 4 Fire

plus common Fault

Stratos-Micra 100

Requires 24V 1.4 Amp Power Supply / Charger

Requires 2 x 12V 12Ah Batteries (for 24 hour

operation in the event of a Power failure

Command Module

A Central Control/Display Panel for

Connecting up to 127 Stratos devices on a

dedicated loop

Date post:	13-Dec-2015
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Sales / Design Presentation. Topics Aspirating Smoke Detection – What it is Fixed Vs Relative...

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