Citation

Von Tomkewitsch R. Fire Safety J. 1983; 6(3): 225-231.

Copyright

(Copyright © 1983, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Well over a million fire detectors are currently in use in the Federal Republic of Germany. Provided they are correctly installed and efficiently maintained, they detect fires reliably at a very early stage. At the present time, the false alarm rate equals about 1% of the number of installed detectors per annum. This false alarm rate must be at least proportionately reduced as further detectors are installed.Since it is scarcely possible to improve tried-and-tested detector designs, the employment of higher-grade detector signal processing methods suggests itself.However, 'more intelligent' detector signal processing using microprocessors calls for an entirely new fire detection system structure: detectors which independently 'decide' whether an alarm criterion is met and then initiate an alarm are replaced by sensors which continuously transmit their measured values to the 'intelligence' panel for evaluation. Passive panels which simply receive alarm signals from activated detectors and indicate these or transmit them to the fire brigade are replaced by active processors using permanently improved algorithms for the detection of real fires.A structural change of this type is possible provided the positive -- and the customary -- characteristics of the conventional technique are not lost, viz. two-wire lines between detector and panel, simple installation and handling, easy detector replaceability, low cost, etc.The pulse detector technology is described in detail; it combines the simplicity of conventional fire detection systems with new characteristics, e.g. identification of individual detectors, permanent functional check of all connected detectors, automatic notification of maintenance requirement prior to a slowly developing fault (e.g. such as that caused by corrosion or contamination), uniform response sensitivity unaffected by drifting from the operating points of the detectors and, above all, greater protection against false alarms.