WIKA CPP30 - Handbuch (Seite 8)

WIKA Betriebsanleitung Hand-Held Thermometer 8
GB
11044608.02 07/2006 D/GB
WIKA Operating Instructions Test Pump
Test Pump
CPP30
4.2 Generation of vacuum
First, check wether the change-over valve (4) has to be actu-
ated (see sticker on the device). For this purpose use a pen or a
small screw-driver. The encasement of the switch is intended to
help prevent unintentional actuation.
Never actuate the change-over valve (4) when the hand test
pump is under pressure or vacuum! Actuate the change-over
valve only when the relief valve is open.
Please make sure that the pressure relief valve (3) is not closed
completely.
Turn the fine adjustment valve (2) clockwise up to the end
(“stop” can be felt).
Make sure that the adjustable knurled nut and counter nut (6)
are in such a position that the spring visible above the nut has
some clearance when the handles (5) are pressed together.
Carefully turn in the pressure relief valve (3) until the valve
closes. You will not notice any “hard stop”.
Operate the handles (5) smoothly and slowly until a vacuum of
max. -0.9 bar is reached.
Turn the fine adjustment valve (2) anti-clockwise to increase the
vacuum up to -0.95 bar. Turn this valve for fine adjustment.
After increasing the vacuum, the reading may slightly increase
again for about 30 seconds, which is caused by thermodynamic
effects, the tube connection and the sealing gaskets. If the
vacuum drop does not come to a standstill, check the measuring
circuit for tightness.
Due to the low volume of each compression stroke of the hand
test pump, only small volume test specimens should be tested.