Inficon 550-300A, Operating Manual

Page: 40 / 128

5-7
Working Modes
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• When "OFF" is set: no zeroing is carried out
• When "ON" is set: zeroing is carried out after the t_B_zeroing delay time
• When "STABLE" is set: zeroing will be carried out within the t_B_zero delay time
provided that the leak rate signal is stable enough to indicate a leak of the set
trigger level 1. If this condition is not complied with within the t_B_zero delay time,
the measuring cycle will be stopped and error message 98 will be generated.
If the chamber pressure is not low enough within the set time
t_F_Readiness_for_measurement to switch over to the measuring mode, the test
procedure will be interrupted indicating the error message 94.
6 After the evacuation of the test sample, the valve V33 is opened and the filling
process of the part with helium can start. If the pressure in the test sample reaches
the set filing pressure p_C_Filling_pressure within the set time t_C_Filling_time, the
valve V33 will be closed again and the filling process will be completed. If the filling
pressure is not reached on time, the measuring cycle will be interrupted indicating
the error message 93.
7 The actual leak test is now started. The measured leak rate is displayed when the
set time t_G_ Measuring_time has expired. If the pressure of the test sample drops
below the pressure p_E_Pressure_drop_threshold during the leak test due to a leak
in the system, the measuring cycle will be interrupted indicating the error message
99.
8
At the end of the measuring time, the valve V32 is opened.
Helium is returned from the test sample to the helium filling facility until the pressure
in the sample has reached the depressurizing pressure
p_D_Depressurizing_pressure. After that, V32 is closed again.
If this does not happen within the set time t_D_Depressurizing _time, the measuring
cycle will be interrupted indicating the error message 95.
9 To remove the residual helium from the test sample, valve V30 opens and the test
sample is evacuated by the pump 4 until the pressure p_B_ Evacuation_pressure is
reached.
This has to be done within the set time t_A_Evacuating _time, otherwise the meas-
uring cycle will be interrupted indicating the error message 96.
10 Valve V30 will be closed. The unit under test is vented to reach atmospheric pressure
via valve V31.
If the set filling pressure for the test sample p_A_Gross_leak_test is not reached
within the time t_E_Ventilation_time, the measuring cycle will be interrupted indicat-
ing the error message 97.
11 After that, the vacuum chamber is ventilated by the Modul1000 (and the external
flood valve V21 ( Fig. 5-1 ), if connected) to reach the atmospheric pressure.