Inficon Pernicka 700H CHLD, Translation Of The Original Operating Instructions

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4 | Description INFICON
18 / 100 Pernicka-700H-CHLD-Operating-instructions-jin76aen1-04-(1911)
4 Description
4.1 Function
The device is a leak detector for detecting and measuring leaks in sealed test objects.
Description of the measurement process
The device is in the "Standby" operating mode at the start of the measurement
process.
The test chamber for receiving the test object filled with the tracer gas, e.g. helium, is
located centrally in front of the device. Insert the test object and close the test
chamber lid. Start the measurement process
Test
chamber
Lid
Fig. 2: Test chamber: Lid open (left) and lid closed (right)
During the automatically running measurement process, first the internal volume of the
test chamber and the volume between the two sealing rings on the upper side of the
test chamber are purged with purge gas, preferably with argon 5.0. After the
completed purging process, the purge gas is pumped out of the test chamber, from
the volume between the 2 sealing rings as well as from the valve block.
After checking the permissible pressure for the operation of the mass spectrometer
(CHLD-Sensor) the valve block is then evacuated. Finally the CHLD-Sensor is
switched on. The CHLD-Sensor is switched off before the valve is opened to the test
chamber. If the pressure is sufficiently low (in particular, the lid of the test chamber
must be closed), the CHLD-Sensor is switched on.
The gross leak test is started. With the gross leak test the current of the helium raw
signal is indicated in amps [A]. A setpoint set before the start of measurement is used
as the abort criterion for this measurement process (see "Set the setpoint for gross
leak test [ } 55]"). If the helium signal exceeds this setpoint, a fine leak test is not
carried out after the gross leak test and the measurement process is terminated. If the