Installation and operating guide
English
14
Generating a vacuum
Warning!
Never activate the changeover valve when the manual test pump is under
pressure or vacuum! Switch over only when the pressure relief valve is
open.
Before generating a vacuum, the changeover valve may need to be activated (see
sticker on the pump). Use a pen or a small screwdriver to do this. The covering of the
switch valve should prevent unintentional activation.
- Attach a suitable adapter if necessary to connect the test specimen to the REF-
CLASS GAUGE.
- Connect the test specimen to the pressure connector for the test specimen. Ensure
seal tightness of the connection.
- Ensure that the pressure relief valve is not completely closed.
- Screw the fine adjustment valve in clockwise almost completely until slight resistance
is felt.
- Screw the pressure relief valve in clockwise cautiously until the valve closes (no "hard
stop" is felt).
- Pump the manual pump cautiously and slowly until a vacuum up to approx. -0.9 bar is
reached.
- Screw the fine adjustment valve out counterclockwise to increase the vacuum
generated to -0.95 bar or set it precisely.
You can reduce the vacuum by opening the pressure relief valve carefully.
After increasing the pressure or vacuum, the display may continue to rise
slightly for about 30 seconds. This is due to thermodynamic effects, the
hose connection, and seals. Regulate the test pressure carefully and
slowly with the manual test pump as needed. If the pressure does not
stop increasing, check the measuring circuit for seal tightness.
