Establishing heat detectors’ thermal sensitivity index through bench-scale tests

Abstract

The current study has established a means of quantifying heat detectors’ thermal response sensitivities through the use of plunge-tunnel tests, so that a fire safety engineer can estimate the detector response times with an acceptable accuracy. Eleven samples of fixed temperature-type detectors were chosen and the response times of the detector under varying test conditions were measured. An analyses of the collected data showed that response time index (RTI) provided the most consistent thermal sensitivity index throughout the different test conditions, among other possible candidates of the indices. In order to check the practical applicability of the RTI values assigned to each detector type, full-scale fire tests were conducted with heptane pan fires under a 3-m high ceiling. The matches between the measured and the estimated response times were excellent for all the detectors, except a “rate-compensated” high-temperature rating detector. Full-scale test results show that the RTI values, which were obtained through the bench-scale tests established with this study, will provide a very practical means of predicting detector-response times with an acceptable precision to fire safety engineers.