DH Instruments E-DWT-H, Operation And Maintenance Manual

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3. OPERATION
Page 35 © 2009 DH Instruments, a Fluke Company
•
To verify or confirm the range from the MAIN RUN screen, use [+/-] or
[RANGE] to view the active range (see Section 3.7.2).
•
See Table 5 for a listing of all selections and settings affected by
AutoRange and their values.
3.7.6 [LEAK CK]
 PURPOSE
To run an automated leak check routine that determines the leak rate of the system
connected to the E-DWT-H
TEST port.
 PRINCIPLE
The LEAK CHECK function is provided as a means of checking and quantifying the leaks that
may be present in the system connected to the E-DWT-H
TEST port.
The principle of the LEAK CHECK function is the measurement of the natural decrease or
increase of pressure in a fixed volume over time. The LEAK CHECK function allows a leak
check time to be set. The total pressure change and the average rate of change over the
leak check time are calculated and displayed.
 OPERATION
To run a leak check, first set the pressure to the desired leak check pressure.
Note
Changing the pressure in a test system causes adiabatic temperature
changes in the pressurized medium that need to have dissipated before a
valid leak measurement can be made. In general, a 0.5 to 1 minute wait
before running a leak check is adequate to allow the adiabatic temperature
change to dissipate and valid leak measurements to be made. However,
stabilization time may be much longer for large pressure changes and as
volume and pressure increase.
To access the LEAK CHECK function, press [LEAK CHECK] from the MAIN RUN screen.
Select <1run> to run a leak test. The display is:
1. Edit field for the time over which the leak rate will be
determined, in seconds.
Set leak check time:
15 s
Edit the leak check time if desired (minimum 1, maximum 999 seconds) and press [ENT] .
Press [ENT] again when ready to start the leak test. The leak test display is:
1. Standard MAIN RUN screen first line showing measured
pressure.
2. Active Q-RPT position indicator
3. Indication that leak test is running and countdown of time
remaining.
5657 psi g Hi
Leak testing 13 s