Sales / Design Presentation
Dec 13, 2015
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
Fixed SensitivityFixed Sensitivity
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
Fixed SensitivityFixed Sensitivity
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
Fixed SensitivityFixed Sensitivity
Fixed SensitivityFixed Sensitivity
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
What is ClassiFireWhat is ClassiFire
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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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%
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)
What is ClassiFireWhat is ClassiFire
And ClassiFire continues to update the histogram for the entire lifetime of the detector
Detector Output 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%
What is ClassiFireWhat is ClassiFire
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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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%
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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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%
Alarm
1 2 3 4 5 6 7 8 9 10 Stratos-HSSD Scale
Setting the ScaleSetting the 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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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%
Setting the ScaleSetting the Scale
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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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%
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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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%
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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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 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
Day/Night ModeDay/Night Mode
Day/Night ModeDay/Night Mode
Detector Output 0%
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req
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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%
Alarm
As night-time approaches, we expect to see a reduction in smoke level, resulting in the fast updating histogram shifting to the left
Day/Night ModeDay/Night Mode
Detector Output 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%
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) …….
Day/Night ModeDay/Night Mode
Detector Output 0%
Co
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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: 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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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%
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
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
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®®
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]
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