Diode temperature sensor with the output voltage proportional to the absolute temperature and its application to the thin film Pirani Vacuum Sensor

It is demonstrated that our proposed new type temperature sensor has a proportional output signal voltage DeltaV to the absolute temperature T as our theoretically predicted equation DeltaV=alphaT by choosing the proper constant dc current I₀, where T is the absolute temperature and alpha a constant. In these experiments square waveform as an ac small signal current deltaI superimposed on the I₀ is adopted and deltaI/I₀ is kept constant against the source voltage fluctuation. As results the good proportional relationships between DeltaV and T over the temperature range of 77-470 K and 140-500 K for the Si pn diode and the SiC Schottky diode, respectively, are achieved. This new temperature sensor is applied to the thin film Pirani vacuum sensor proposed by us to measure the temperature difference between temperatures by double pulse heating of a cantilever using a diode-heater driven by different constant forward voltages. This prototype vacuum sensor is sensitive in the very wide vacuum pressure range of 1times10^-2 -10⁵ Pa at least.