cold cathode pressure gauge

 
 

A cold cathode pressure gauge ionizes the rest gas in the system and uses the ion current as a measure of the pressure. In contrast to a (hot) ion gauge, the electrons for the ionisation of the rest gas are not created by a hot filament but by a high voltage discharge. In combination with a magnetic field, this creates a confined electron plasma which ionises the rest gas. The pressure range in which a cold cathode gauge works is between between 10-2 and 10-9 mbar, so it can measure at higher pressures than a hot ion gauge but it is less reliable in the UHV range. Also, the ion current is not simply proportional to the rest gas pressure.

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