As part of the study and development of a variable thermal resistor (VTR), we present an improved thermal resistance measurement method for the VTR in the presence of unwanted signal drifting. To measure the change of thermal resistance, instead of waiting for the steady state value of the temperature signal, we repeatedly measure only the early transient part of the thermal response signal and then fit to get thermal resistance estimation. The required lengths of measurement were studied for the tests with various thermal time constants. Using this method, we performed thermal switching tests with various material pairs in contact in order to find the material pair that minimizes thermal contact resistance.
