91518 Multigas Analyzer Service Manual
4-23
Maintenance
Leak Check Test
The leak test is used to determine if the 91518 leaks by measuring the leak rate after applying pressure. The
91518 should not be in service during a leak test, and power should be disconnected from the unit.
To test for leaks in the 91518:
1 Install a D-fend water trap (P/N 717-0447-00) into the 91518.
2 Connect the manometer and bulb valve, using a T-connector, to the 91518 at the port on the water trap.
3 Use your fingers to cover the Ref. and exhaust ports, to prevent leaking.
4 Pump the system pressure to 180 mmHg with the bulb assembly, and then close the bulb valve.
5 Pinch the hose closed with a hemostat.
6 Verify that the leak rate is less than 10 mmHg per minute.
7 Remove the test setup.
If the leak test fails:
1 Change the water trap, and repeat steps 1 through 6.
2 Change the gas filter, and repeat steps 1 through 6.
3 Inspect all internal tubing and pneumatics for damage or wear, and replace as needed. Repeat steps 1
through 6.
Figure 4-21: 91518 leak test configuration
