Owner's manual
Page 4 of 12  DRD-E Flame Detector Installation Manual 
2-3-0-1376/ISS1/NOV10 
© 2010 Hochiki Europe (UK) Ltd 
1 General 
1.1 Description 
The flame detector is designed for use where open flaming fires may be expected. It responds to the light 
emitted from flames during combustion. The detector discriminates between flames and other light sources 
by responding only to particular optical wavelengths and flame flicker frequencies. This enables the detector 
to avoid false alarms due to such factors as flickering light sources. 
1.2 Alarm Response Modes 
The detector is normally configured to latch into an alarm state when a flame is detected. The supply to the 
detector has to be removed in order to reset the detector. 
1.3 IR Detection Basics 
Flame detectors are classified into two types by their principle of detection. UV detectors are sensitive to 
ultraviolet, and IR detectors are sensitive to infrared. 
This DRD-E detector can detect IR radiated from flames. Flames radiated from a fire have an IR peak 
emission of 4.3um occurring during the CO2 formation due to the combustion of hydrocarbons from 2 to 15 
Hz. 
Fig 1 : External View of DRD-E 










