INFICON BPG400 ATM to Ultra-High Vacuum Gauge - Manual (Page 56)

56
tina03e1-b (2004-02) BPG400 v1.om
The gas type dependence in the pressure range 10 -2 … 1 mbar can be compen-
sated by means of the following formula:
p
eff
= C × indicated pressure
where Gas type Calibration factor C
Air, O
2
, CO 1.0
N
2
0.9
CO
2
0.5
Water vapor 0.7
Freon 12 1.0
H
2
0.5
He 0.8
Ne 1.4
Ar 1.7
Kr 2.4
Xe 3.0
(The above calibration factors are mean values.)
The gas type dependence in the pressure range <10 -3 mbar can be compensated
by means of the following formula (gauge adjusted for air):
p
eff
= C × indicated pressure
where Gas type Calibration factor C
Air, O
2
, CO, N2 1.0
N
2
1.0
He 5.9
Ne 4.1
H
2
2.4
Ar 0.8
Kr 0.5
Xe 0.4
(The above calibration factors are mean values.)
A mixture of gases and vapors is often involved. In this case, accurate
determination is only possible with a partial-pressure measuring instru-
ment.
Calibration in pressure range
10
-2 … 1 mbar
Calibration in pressure range
<10
-3 mbar