Minimum reading pressure gage with dual function sensor

摘要

An electronic device for observing temperature and pressure and for indicating pressure, especially very low pressures. The device has a single sensor element for responding to both temperature and pressure. The device includes a sequence timer for causing the device to first observe the resistance of the sensor when the device is first turned on. The timer then applies a voltage across the sensor, causing a known current to flow through the sensor. The current heats the sensor an amount corresponding to density and therefore the pressure of the gas to which it is exposed. A calculating device is provided for calculating the temperature from the observed value of the initial sensor resistance and the pressure from the observed values of current flow and subsequent sensor resistance. A display is provided for indicating the calculated pressure.