Measuring thermophysical properties of gases with a single thermocouple: Peltier vacuum gauge

Abstract

Using a single thermocouple as a heater and temperature sensor simultaneously, we have developed a new type of gas pressure sensor termed the Peltier vacuum gauge (PVG). The PVG measures gas pressure by allowing an AC current carrying thermocouple, which is in contact with gases, to measure its own temperature. An AC current carrying thermocouple generates Joule heating along the wire and Peltier heating/cooling at the junction, and its temperature is determined by the thermophysical properties of surrounding gases which in turn depends on pressure. The complementary nature of the Peltier effect and the Joule heating allows the PVG to possess an excellent sensitivity over a wide range of pressure from 10(-4) Torr to atmospheric pressure. (C) 2006 Elsevier B.V. All rights reserved.