Exploiting the transient response of a Pirani gauge sensor for beyond atmospheric pressure measurement

In this paper, the design of an interface circuit for exploiting the transient response of a Pirani gauge sensor for beyond atmospheric pressure measurement is proposed. Based on the fact that although the thermal conductance of gas saturates for pressure over 100 mbar leading to the saturation of steady response, the transient response of a Pirani gauge sensor is still sensitive owing to the increase of heating capacitance of the gas. An original method is proposed to exploit the transient response. Thanks to the proposed interface circuit, pressures varying from 0.9 bars to 3 bars, which are limited by the model used, can be clearly distinguished by simulation results. Theoretical analysis shows that the measurable pressure range can go beyond that limit.