Pressure sensor

Abstract

A vacuum-driven gas gauge proximity sensor for sensing a difference between a reference surface standoff and a measurement surface standoff is disclosed. Unlike existing proximity sensors, the vacuum-driven gas gauge proximity sensor uses a vacuum to reverse the traditional flow of gas through a proximity sensor, such that gas flows inward across measurement and reference standoffs through measurement and reference nozzles. The conditioned ambient gas that is vacuumed into the reference and measurement nozzles flows through reference and measurement channels that are coupled at a junction into a single channel. The single channel is coupled to the vacuum that is used to evacuate the conditioned ambient gas through the proximity sensor. A bridge channel couples the reference and measurement channels. A mass flow sensor along the bridge channel monitors flow rates to detect measurement standoffs that can be used to initiate a control action. A pump-driven liquid flow proximity sensor is also disclosed.

Dependencies are inferred from the claim text.