TY - JOUR PY - 2002// TI - Determination of dynamic model parameters of smoke detectors JO - Fire safety journal A1 - Bjorkman, J A1 - Baroudi, D A1 - Latva, R A1 - Tuomisaari, M A1 - Kokkala, Matti SP - 395 EP - 407 VL - 37 IS - 4 N2 - A simple model for the dynamic response of point-type smoke detectors is described. The model is based on two independent parameters: the characteristic length and the static response threshold. Experimentally determined values of the parameters for six commonly used point-type smoke detectors are reported. In the tests the free stream flow velocity was varied in the range of 0.2-0.8 m/s and the rate of rise of smoke density in the range of 0.1-2 dB/ms. The model parameters were determined from the experimental data by using the least squares fitting with regularisation. The characteristic length was found to vary in the range of 2-10 m indicating a smoke entry time constant in the range of 10-50 s at a flow rate of 0.2 m/s typical of smouldering fires. The response of photoelectric detectors was described by the model reasonably well. In the case of ionisation detectors, significant deviations were found. A method of using the model in fire safety engineering calculations is also presented.

LA - SN - 0379-7112 UR - http://dx.doi.org/ ID - ref1 ER -