Automatic fire detection

As soon as a fire starts, it produces a variety of environmental changes that help make its presence known.

The elements of a fire that are most often used as the basis for detection are heat, smoke (aerosol particulate), characteristic noise, and light radiation.

Complicating the detector's ability to detect a fire are two facts:

1. not all fires produce all of the elements, and
2. nonfire conditions can produce similar ambient conditions.

The fire protection engineer must decide which of the elements produced by a fire might be expected from hostile fires and which similar ambient conditions might result frm nonfire situations.

Even if all of the elements - heat, smoke, noise, and light - are present in a given fire, the magnitude of the different elements must exceed some theoretical basic level during fire development. It is also helpful to determine which elements appear first. This is especially true if life safety is involved. This sub-directory will discuss various automatic fire detectors and their principles of operation.

I Heat Detector
II Smoke Detector
III Flame Detector
IV Noise Detector

Note: The author concentrates on the detection of fires in buildings and installations. The detection of wildland fires is an important subject in light of environmental and safety issues, but the detection mechanisms and equipment is different. The NASA earth observatory web-page gives a broad picture of possible technologies. A more detailed case study is published by the Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin - Madison.