User guide

CDG100-OP-LIT (2010-1) 23
4.2 Zeroing the Gauge
The gauge is factory calibrated while "standing upright"
(→ "Calibration Test Report").
We recommend performing a zero adjustment, when the
gauge is operated for the first time.
Due to long time operation or contamination, a zero drift could
occur and zero adjustment may become necessary.
For adjusting the zero, operate the gauge under the same con-
stant ambient conditions and in the same mounting orientation
as normally.
The output signal (measuring signal) is depending on the moun-
ting orientation. The signal difference between the vertical and
horizontal mounting orientation is:
F.S. ∆U / 90°
1000 Torr
≈2 mV
100 Torr
≈10 mV
10 Torr
≈50 mV
1 Torr
≈300 mV
0.1 Torr
≈1.8 V
If the gauge is operated via a controller, the zero of the
whole measuring system has to be adjusted on the
controller: first, adjust the zero of the gauge and then,
the zero of the controller.