Capacitive pressure sensor for detecting pressure and differential pressure with diaphragm includes circuit unit, switch selecting circuit, switch, fixed capacitor and comparison unit

摘要

Sensor has circuit unit (23), emitting constant current; fixed capacitor (Cc) with fixed capacitance; switch selecting circuit (21); switch (29) and mono-multi unit (26) for switching between capacitor discharge and charge; and comparison unit (25) controlling charge until electric potential of capacitor reaches pre-determined tension and discharge when potential reaches pre-determined tension. An Independent claim is also included for the description of the detection equipment.