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vd84-201113
Warm-up-time
Pressure is displayed immediately after the unit is switched on. To take ad-
vantage of the maximum accuracy in fine vacuum range it can be appropriate to
allow for stabilization time of 2 minutes, especially when extreme pressure
changes have occurred.
Accuracy
The unit is factory adjusted. Through contamination, ageing or extreme climatic
conditions the need for readjustment may arise.
Accuracy therefore may be reduced in the range below 10
-2
mbar and above
20 mbar.
Dependency on gas type
Due to the Pirani sensor, measurements are depending on composition and type
of the gas being measured. The unit is adjusted for N
2
and dry air. With He and
CO deviations will be almost negligible below 0,5 mbar.
For other gas types a correction factor can be entered which produces correct
pressure readings below 0,5 mbar (see chapter 5.5).
Proper Use
The VD84 serves exclusively to provide total pressure measurements in gaseous
media in the range 100 – 1x10
-3
mbar. It may only be connected to components
specifically provided for such purpose.
Improper Use
The use for purposes not covered above is regarded as improper, in particular:
- the connection to components not allowed for in their operating instructions
- the connection to components containing touchable, voltage carrying parts.
No liability or warranty will be accepted for claims arising from improper use.
The user bears the responsibility with respect to the used process media.
The device is not designed for use in corrosive gas atmos-
phere. Aggressive media such as halogenides, carbon or oxy-
gen plasma can reduce sensor life-time!
Dust, oil or condensing vapours will affect sensor performance
and may cause malfunction!
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