GE Druck ADTS 405, User Manual

Page: 80 / 134

K114 Issue No. 9
5 - 8
Testing and Fault Finding
5.6 Further Testing
The following tests should only be carried out if a pneumatic leak or a controller
instability is suspected.
Test Environment and Preliminary Operations
These tests should be carried out in a room with a stable temperature environment
within the operating temperature range. The room must be free from drafts.
Review and become familiar with the whole of the test procedure before beginning the
test procedure.
The unit must be thermally stable; switch on and leave the unit for at least one hour to
achieve thermal stability.
Change the units to mbar as follows:
(1) Press SETUP then select [UNITS]. Repeatedly select [NEXT] until the
display shows “mbar”.
(2) Select [SAVE] and then press CLEAR/QUIT twice and the display now shows Ps and Pt
in units of mbar.
Pressure Leak Check
This section verifies that the unit is leak tight under positive pressure conditions.
(1) Press LEAK MEASURE/CONTROL to enter control mode.
The display shows “Aim” in place of “Leak Measure”.
(2) Enter a Ps aim of 1016 mbar by pressing: ALT/Ps, 1, 0, 1, 6, ENTER .
(3) Enter a Qc aim of 272 mbar by pressing: SPEED/Qc, 2, 7, 2, ENTER .
Wait for the aim values to be achieved then wait for 1 min.
(4) Press LEAK MEASURE/CONTROL to return to Leak Measure mode.
(5) Press RATE TIMER and select [WAIT 05:00], [TIME 01:00]. Observe that the
"Waiting" time is shown on the display as it counts down, followed by the "Timing"
time.
(6) At the end of the "Timing" period, the display shows the rate of change of
Ps, Qc and Pt with a “
T ” to indicate timed average.