System Sensor BS5839 manual Rate of rise heat detector, Areas subject to rapid changes, Normal use

Application Guide

Up to 100M

		Beam
	Combined	attenuated by	Reflector
height25mtoUp		smoke plume
	Emitter /
	Receiver Unit

Figure 2.3.3. Operation of Reflective Type Optical Beam

Smoke Detector

Beam detectors are more complex to install than ordinary point smoke detectors and it is advisable to consult an application guide for the use of projected beam smoke detectors before considering the use of these detectors.

Detector type	Application	Not suitable for
Ionisation smoke detector	General purpose smoke detector – better	Areas subject to smoke, steam, dust or
	for fast flaming fires	dirt during normal use
Optical smoke detector	General purpose smoke detector – better	Areas subject to smoke, steam, dust or
	for smouldering fires	dirt during normal use
Photo-thermal multi-criteria detector	General purpose detector – good for	Areas subject to smoke, steam, dust or
	smouldering and fast flaming fires	dirt during normal use
Optical beam smoke detector	Large and high rooms	Areas subject to smoke, steam, dust or
		dirt during normal use
Rate of rise heat detector	Areas subject to smoke, steam, dust or	Areas subject to rapid changes of
	dirt during normal use	temperature or temperatures over 43°C
Fixed temperature detector (58°C)	Areas subject to smoke, steam, dust or	Areas subject to temperatures over 43°C
	dirt and rapid changes of temperature
	during normal use
High temperature fixed detector (78°C)	Areas subject to smoke, steam, dust or	Areas subject to temperatures over 65°C
	dirt and temperatures over 43°C during
	normal use

Figure 2.3.1. Selection of Fire Detectors

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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.