Vacuum sensing based on the influence of gas pressure on thermal time constant

In this paper we propose a novel operating principle for thermal vacuum sensor. The sensor considered in this work consists of thermopiles and thermally isolating membrane structure. The operating principle of such sensor would be based on monitoring thermal time constant dependence on pressure. In order to get the most prominent effect, sensor fabricated on SOI wafer is studied. Simulation was performed using 1D analytical model. It is shown that sensors performance could be improved by increasing the number of thermocouples. Apart from that it is demonstrated that performance of such sensor depends also on gas present in the housing so the same device could be also used as a gas type detector.