Agilent Technologies Helium User Manual page 64

Technical Information
Hold
Digital Leak Rate
Test Port Pressure Appears on the Home screen and represents the test port
Leak Detector Status Appears below the test port pressure reading and indicates the
Leak Detector
Condition
Setpoints Status
Box
Zero
64
Places the system in Hold (while in Test, press Test again to
starts Hold); keeps the test port under vacuum and does not
vent. Use Hold to keep the system under vacuum, while taking
the leak detector out of test. This is useful if you want to let the
leak detector clean up the helium background, while keeping the
system under vacuum.
Since the test port pressure gauge is located on the test port
side of the isolation valve, a subsequent rise in test pressure
can be observed while in this mode.
Correlates directly with the log and linear bar graph leak rate
display. The units for the measurements are selected in the
Settings > Main Settings menu (see Section "Settings Menu").
pressure as measured by a thermocouple device mounted on
the valve block just below the test port. The pressure transducer
and associated electronics are intended to protect the leak
detector from damage due to over-pressure conditions. Use an
external pressure transducer if the test process requires a more
accurate monitoring of the test object pressure.
current leak detector operating state. The normal operating
states are detailed in the Table 11.
Appears below the Leak Detector Status and indicates the
current leak detector condition during abnormal conditions. See
the Table 11 for a list of leak detector conditions.
Appears below the Leak Detector Condition on the left-hand
center of the Home screen when any of the four independent
set points are enabled and activated or de-activated.
Zeroes out the helium leak indicated on the display. The Zero
button darkens while zeroing is taking place. The leak rate must
be less than 4.0E-7, while in Test, to allow a cross over to Fine
Test.
The Zero button is only active while the leak detector is in the
Test and Fine Test states of operation.
The leak detector automatically subtracts the recorded
background signal to display only the real leak rate.
Agilent Helium Leak Detector User Manual