pressure measurement


Pressure measurement is essential in vacuum technology. Different types of pressure gauges work for different pressure regimes.

In the UHV range, pressure gauges ionize the rest gas atoms and molecules and measure the pressure via the size of a current from these ions. Hot filament ion gauges or cold cathode ion gauges and even mass spectrometers can be used. For these gauges, there is an upper pressure over which they cannot be operated.

At higher pressures, in the roughing line for example, pirani gauges or mechanical gauges can be used. These gauges can operate at any pressure, also in UHV, but they are not sensitive to pressure changes anymore. Mechanical gauges are only sensitive down to a pressure of 10-2 mbar or so and are not discussed further on this site.

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