User guide

page 38 of 61
Documents are only to be used and distributed completely and unchanged. It is strictly the users´ responsibility to check carefully
the validity of this document with respect to his product. Manual-no.: 999248 / 28/04/2011
The vacuum gauge was adjusted using factory standards, which are traceable
through regular calibration in an accredited laboratory (German Calibration service)
to the Germannationalpressurestandard.Dependingon the process and/or ac-
curacyrequirements,checktheadjustmentandreadjustifnecessary.Forreadjust-
ment, the device has to be adjusted both at atmospheric pressure as well as under
vacuumbutonly if thereference pressuresarecertainly known.The adjustment
modecanbe activated only iftheprocess control isinactive.Press key ”START/
STOP” if necessary. In the range between 20 and 700 mbar no adjustment is pos-
sible; ---- mbar is displayed.
Adjustment at atmospheric pressure
An adjustment at atmospheric pressure is only possible if the
pressure is higher than 700 mbar.
Ventilatethemeasurementconnectionofthecontrollerand/or
thevacuumsystem.Makesurethatthepressuretransducer
is at atmospheric pressure.
➨ In function ”Conguration” select program ”Adjustment” at
the controller.
➨ Usetheselectionknobtoadjustthereadingtothecurrent
atmospheric pressure.
➨ Presstheselectionknobtoconrm.
Adjustment under vacuum
An adjustment under vacuum is only possible if the pressure
is lower than 20 mbar absolute.
Evacuate the measurement connection of the controller to
a pressure < 0.1 mbar (e. g. by applying a good two-stage
rotary vane pump).
➨ In function ”Conguration” select program ”Adjustment” at
the controller.
☞ The reading is automatically adjusted to ”zero”.
➨ Presstheselectionknobtoconrm.
Adjustment at a reference pressure
Instead of adjustment under vacuum to a pressure < 0.1
mbar, adjustment to a precisely known reference pressure
within the range of 0 ..... 20 mbar is possible. Evacuate the
measurement connection of the controller to a pressure within
0 ..... 20 mbar
➨ In function ”Conguration” select program ”Adjustment” at
the controller.
☞ The reading is automatically adjusted to ”zero”.
➨ Usetheselectionknobtoadjustthedisplaytotherefer-
ence pressure at the vacuum line within the range of 0 ..... 20
mbar.
➨ Presstheselectionknobtoconrm.
1013 mbar
0 mbar
0...20 mbar
6 Readjustment of the controller
NOTICE
Note: To determine the actual atmospheric pressure, use an accurate barometer or get accurate read-
ing from the weather service, the next airport.......(take into account the difference in altitude between e.
g. airport and laboratory).
Note: Adjustment under vacuum with an actual pressure higher than 0.1 mbar reduces the accuracy of
the measurement. If the pressure is signicantly higher than 0.1 mbar, adjustment to a reference pres-
sure is recommended.
Note: The accuracy of the value of the reference pressure will directly affect the accuracy of the adjust-
ment. If the nominal ultimate vacuum of a diaphragm pump is used as reference vacuum, the accuracy
of the controller might be doubtful. The diaphragm pump may not achieve the specied value (due to
condensate, poor condition, failure of valves or diaphragm, leaks).