Jiang YL, Chen T, Yuan HY, Zhang YM, Zhu YQ, Wang JJ, Ma SH (2006) 'Fire detection technique based on photoacoustic principle.' (Science Press USA Inc: Monmouth Junction) 916-919

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Keywords:

Photoacoustic, fire detection, infrared spectrum, gas detection, gas-analysis, Spectroscopy, sensitivity, sensor,

Abstract: A fire detection system based on photoacoustic (PA) principle is reported. The system operates by selecting gas generated in combustion instead of conventional smoke and temperature as parameter, so it can realize an early fire detection. It consists of a broad-spectrum infrared source ranging from 2 to 5 in, a absorption path, a photoacoustic cell, a lock-in amplifier and a sensitive microphone as photoacoustic signal receiver. The reference cell filling with the high-purity gas (here is carbon monoxide)is used as a gas filter selector. The change of gas concentration to be measured in the air is converted into electrical signal and superposed on the initial signal. The gas concentration in the air can be calculated by a simple algorithm according to the relationship between changed photoacousitc signal and gas concentration. Two kinds of Chinese standard fires are tested by the PA detection system. The measurement results show that the system reacts very well to both fires. And a detection limit of 3 ppm of carbon monoxide is achieved experimentally.