VACUUBRAND PC 301 - Manual (Page 24)

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.: 999147 / 17/06/2014
page 24 of 40
Readjustment of the vacuum gauge DVR 2
➨ Keep key UP/DOWN pressed while switching
on.
☞ The vacuum gauge switches into the adjust-
ment mode (indicated by a warning triangle).
☞ The arrow at the right indicates, that the pres- The arrow at the right indicates, that the pres-
sure reading can be increased by using key
UP/DOWN.
➨ Press key UP/DOWN to increase the reading
to the actual atmospheric pressure.
The equipment has been adjusted at the factory. In general, there is no need for adjustment by the user
because of the excellent longtime stability.
Depending on operation conditions, type of application and accuracy requirements, an inspection and
readjustment may become necessary.
Admit air to the vacuum gauge. Make sure that the vacuum connection at the vacuum gauge is at at-
mospheric pressure.
Attention: Determine the exact actual atmospheric pressure, e. g. by using an accurate barometer or
get accurate reading from the weather service, e. g. at the next airport, etc. (take into account the differ-
ence in altitude between e. g. airport and laboratory).
To reduce the reading:
➨
Press key MODE to change the direction of
adjustment. The arrow moves to the left in-
dicating that the pressure reading can be re-
duced.
➨ Press key UP/DOWN to reduce the reading.
Evacuate the vacuum gauge to a pressure <0.5 mbar (<0.4 Torr) e. g. by applying a good rotary vane
pump.
➨ Keep key UP/DOWN pressed while switching
on.
☞ The vacuum gauge switches into the adjust-
ment mode (indicated by a warning triangle).
☞ The reading is adjusted automatically to
”zero”.
Attention: Adjustment under vacuum with a pressure higher than 0.5 mbar (0.4 Torr) reduces the ac-
curacy of measurement. If the pressure is significantly higher than 0.5 mbar (0.4 Torr), adjustment to a
reference pressure is recommended .
➨ Press key ON/OFF to confirm the adjustment
and to terminate the adjustment mode.
Adjustment at atmospheric pressure
+
➨ Press key ON/OFF to confirm the adjustment
and to terminate the adjustment mode.
Adjustment under vacuum
+