Experimental determination of the time constant of a thermoresistive sensor

The thermal time constant of a thermoresistive sensor is defined in terms of its physical properties such as mass m, specific heat c, area A and overall heat transfer coefficient U to the surroundings. Measurement of these parameters (e.g. c and U) may involve lengthy experimental procedures. An experimental method using only electrical quantities, to determine the intrinsic thermal time constant, is described. In the proposed procedure, the physical properties of the sensor are not required. A formulation, to compensate for the measurement errors due to electrical heating of the sensor, is presented