Models 947, 948 and 960 Leak Detectors Operations and Service Manual
3-15
3. Press the
START
button.
❑
The VENT LED goes off and one second later, the START LED illuminates.
❑
The TEST LED illuminates.
❑
The START LED goes out.
❑
The LEAK RATE range exponent goes to the most appropriate range.
4. Introduce helium to the unit under test.
The 947/948/960 automatically traces the under test helium signal up range through the
Reject Set Point. If larger than the pre-set Reject value, the leak rate signal reads this
maximum level. The REJECT LED lights up.
5. Press and hold the
VENT
button approximately 1 second until the 947/948/960 is in
VENT mode.
❑
Test LED goes off.
❑
Vent LED illuminates.
6. Remove the unit under test from the test port.
❑
VENT LED is on.
Auto ranging procedure is complete.
3.5.2 Manual Ranging
Manual ranging is used when the range of the failure level for the part under test is known.
To range manually:
1. Press the
VENT
button.
❑
TEST LED goes off.
❑
VENT LED illuminates.
2. Select the
MAN
position of the AUTO/MAN MODE switch in the Leak Rate Range
section.
3. Press the
SMALLER
or
LARGER
button to select the exponent of the leak rate range to
which you want to test.
4. Securely attach the new unit under test to the test port while the 947/948/960 is in
VENT mode.
