Smoke Alarm User Manual

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Note: This document is based on the recommendations of BS5839 Part 1: 2002. It is intended only as a guide to the application of fire detection systems.
Reference must be made to relevant national and local standards.
DRIFT COMPENSATION AND SMOOTHING
Drift Compensation and Smoothing eliminate nuisance
alarms and provide a consistent progressive alarm sensitivity
threshold throughout the period between service intervals.
In many instances this will result in an improved economic
performance through savings in the cost of maintenance by
extending the detector cleaning interval.
Intelligent sensors incorporate enhanced digital signal
processing, eliminating spurious peaks.
5251REM, 5251EM AND 5251HTEM HEAT SENSORS
The 5251 range of static element and “rate of rise”
temperature sensors provide solutions for a wide range of
applications.
The 5251EM and 5251HTEM are fixed temperature analogue
addressable sensors employing low mass thermistors and
microprocessor technology for fast response and linear
temperature sensing. Their linear response allows these
sensors to be used to signal temperatures over the range of
58°C (Class A1S) to 78°C (Class BS).
The 5251REM uses the same thermistor and microprocessor
technology to provide an alarm when the rate of rise
in temperature exceeds 10°C/minute (typical) or if the
temperature exceeds a threshold of 58°C (Response Class
A1R).
5251REM is approved to EN54-5: 2000 Class A1R
5251EM is approved to EN54-5: 2000 Class A1S
5251HTEM is approved to EN54-5: 2000 Class BS
Specifications
Height: 51mm in B501 Base
Weight: 102g excluding base
System Sensor Intelligent Product Range
Processed versus Unprocessed Signals
Time: hours
Processed
Unprocessed
PW4 µs
Effects of Drift Compensation
Time: years
Sensor value
Low fault threshold
Analogue sensor value
Maintenance levels
Adjusted thresholds