INFICON HPG400 ATM to High-Vacuum Gauge - Manual (Page 45)

tina31e1 (2004-05) HPG400 v1.om
45
Appendix
over
range
1E+03
1E+02
1E+01
1E+00
0.0 0.5 1.0 1.5 2.5 3.5 4.5 5.5 6.5 7.5 8.5 9.5 2.0 3.0 4.0 5.0 6.0 7.0 9.0
1E–01
1E–02
1E–03
1E–04
1E–05
1E–06
8.0
10.2
10.0
Measuring signal U[V]
Pressure p [mbar]
Hot cathode range and Pirani range require different conversion formulae:
p = 10
U - c1 ⇔ U = c1 + log p
p = 10
(4 × (U - c2)) ⇔ U = c2 + 0.25 log p
Where U p c1 c2
[V] [mbar] 7.5 9
[V] [Torr] 7.625 9.031
[V] [Micron] 4.625 8.281
[V] [Pa] 5.5 8.5
Switch position
↔ HP>
Threshold
0 or 1
2 or 3
4 or 5
6 or 7
8 or 9 1 mbar (factory setting)
5×10 –1 mbar
2×10
–1
mbar
1×10
–1
mbar
5×10 –2 mbar
A: Relationship Output
Signal – Pressure
Conversion curve
Conversion formula
hot cathode range
Conversion formula
Pirani range
Changeover threshold
hot cathode
↔ Pirani