Factors ionisation gauge correction

Some values are given in Table 5.4. They are almost identical with the reciprocals of the ionisation gauge correction factors given in Table 5.1. 

Note />HV was measured with an ionisation gauge, the reading of which is gas-dependent. The estimate of h hv would not, therefore, be shown on the gauge and an appropriate correction factor must be applied (see Chapter 5). 

The ion yield (and hence /+) for hot cathode ionisation gauges depends on the type of gas involved since some gases are easier to ionise than others. Indirect reading gauges are calibrated using N2 as the reference gas. To obtain the actual pressure for gases other than N2, the indicated pressure must be multiplied by a correction factor for the gas involved. Thus ... 

Table 5.1 Some correction factors for the adjustment of indicated ionisation gauge pressure to gas type...

The ionisation process does not reproduce, in the output of ions, the relative amount of gas at the source. By the use of reference gases, such as N2, the gauge sensitivity can be established and, by the use of appropriate correction factors, differing extents of ionisation can be accounted for. 

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See also in sourсe #XX -- [ , ]

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