VACUUBRAND PC 3012 VARIO - Manual (Page 41)

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.: 999164 / 19/05/2009
page 41 of 75
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 CVC 3000 and/
or the vacuum system. Make sure that the pressure trans-
ducer is at atmospheric pressure.
➨
In function ”Configuration” select program ”Adjustment” at
the controller.
➨ Use the selection knob to adjust the reading to the current
atmospheric pressure.
➨ Press the selection knob to confirm.
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 CVC 3000 to
a pressure < 0.1 mbar (e. g. by applying a good two-stage
rotary vane pump).
➨
In function ”Configuration” select program ”Adjustment” at
the controller.
☞ The reading is automatically adjusted to ”zero”.
➨ Press the selection knob to confirm.
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 measure-
ment connection of the CVC 3000 to a pressure within 0 .....
20 mbar
➨
In function ”Configuration” 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 confirm.
1013 mbar
0 mbar
0...20 mbar
Readjustment of CVC 3000
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 significantly 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 specified value (due to
condensate, poor condition, failure of valves or diaphragm, leaks).