Servomex NanoTrace DF-760E, Instruction Manual

Page: 74 / 182

70 DF-760E User Interface
Figure 55: Purge Cancel
7.5.9.4 Pump Capacity Test
The pump capacity test can be used to determine the ultimate vacuum that the aspirator or
pump is capable of pulling. Proper flow through the analyzer is a direct result of the proper
balance between the pressure on the analyzer inlet and the vacuum at the analyzer outlet. If
either is incorrect, the flow will suffer and the moisture readings will not accurately reflect
the condition of the process gas.
Figure 56: Pump Capacity Test
The test is automatic in nature, in that once started, the analyzer isolates the moisture cell
by closing the upstream and downstream valves and then the vacuum is monitored for 20
seconds and is displayed on the screen. Any pressure lower than 115 Torr is considered
acceptable. If the aspirator or pump is unable to pull 115 Torr, a failure is indicated by the
appearance of Figure 57 and the recommendation to rebuild the pump or check for leaks.
At the end of the 20 second test, whether the aspirator or pump passes or fails, the user
must hit Escape to return to the main display.
After the pump test is complete, an entry is automatically put in the pump capacity test log
as shown in Figure 58. See page 61 for additional information on the pump test log.
Figure 57: Pump Pressure Failure