INFICON MPG40x ATM to Ultra-High Vacuum Gauge - Manual (Page 31)

tina48e1-b (2008-10) MPG400-401.om
31
In the range below 10 -5 mbar, the pressure indication is linear. For gases other
than air, the pressure can be determined by means of a simple conversion formula:
p
eff
= K × pressure indicated
where gas type K
air (O
2
, CO, N
2
) 1.0
Xe 0.4
Kr 0.5
Ar 0.8
H
2
2.4
Ne 4.1
He 5.9
These conversion factors are average values.
A mixture of gases and vapors is often involved. In this case,
accurate determination is only possible with a partial pressure
measurement instrument, e.g. a quadrupole mass spectrometer.
Indication range below
10
-5 mbar