
Preventive Maintenance
Leak Test and Pump Checkout
4-10
Model 49
i
Primary Standard Instruction Manual
Thermo Fisher Scientific
7. Note the pressure as P
NO
.
8. Connect the pressure transducer to the normally closed solenoid port.
9. Plug the solenoid power line into the appropriate connector on the
measurement interface board. Make sure the solenoid is activated by
choosing
Pressure
from the Diagnostics menu.
10. Note the pressure as P
NC
the solenoid is faulty
11. The solenoid is faulty if either P
NO
or P
NC
is greater than the pressure
determined in the “External Leaks” section described previously.