Patent ID: 8997576
Filing Date: 2015-04-07
Classification: G01L

Abstract:
1. A method for detecting the presence of an unacceptable quantity of gas molecules in the reference vacuum cavity of a capacitance diaphragm gauge (CDG), the method comprising: inserting an independent pressure transducer into the reference vacuum cavity of the CDG, the independent pressure transducer comprising a ring anode, at least one cathode and a magnet, the magnet positioned to generate a magnetic flux along a central axis of the ring anode; applying a high voltage between the anode and the cathode to generate an electrical field to ionize gas molecules proximate to the anode and the at least one cathode; measuring a magnitude of a current flowing between the anode and the cathode via ionized gas molecules; and sensing when the magnitude of the current exceeds a predetermined acceptable current magnitude to thereby determine that the quantity of gas molecules in the reference vacuum cavity exceeds an acceptable quantity of gas molecules.