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Agilent Technologies Helium Leak Detector
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Zero Enable
Turns on or off the zeroed out background. This feature excludes
the background leak from the leak rate signal.
Helium background represents helium that is in the system but
does not come from the part under test. If the background is zeroed
out, a more accurate measurement of the leak rate of the part is
determined. If Zero Enable is turned ON, the background is
excluded; if it is turned OFF, the system displays the full helium sig-
nal, including total background.
Table 3-1 Leak Detector Operating States
Display
Description
Calibrating
Indicates that the leak detector is currently performing a calibration routine.
Test
Indicates that the leak detector is in Test mode. When in Test mode, the Test
Port valve opens and the leak detector is ready for leak testing. Test leak rate
range is 1E-4 to 1E-8 (MDL 5E-9).
Fine Test
Indicates that the leak detector is in Fine Test mode. When in Fine Test mode,
the test port valve opens and the leak detector is ready for fine leak testing.
Fine Test leak rate range is 9E-7 to 1E-11 (MDL 5E-12).
Hold
Indicates that the leak detector is in Hold mode. When in Hold mode, all but
the foreline valves are closed, isolating the test port and any test objects or
fixturing from the leak detector vacuum system. Use Hold when you want to
keep the test port under vacuum without venting the test volume; this helps the
system clean up.
Roughing
Indicates that the leak detector is currently performing a Roughing level
evacuation of the test port and any attached test objects or fixturing attached to
the test port.
Std Leak
Indicates that the optional internal calibrated leak standard valve is open and
that the leak detector is reading the leak value.
Vented
Indicates that the test port is vented to atmosphere. The test port and all objects
attached to the test port are isolated from the leak detector internal vacuum
system.
Table 3-2 Leak Detector Condition States
Display
Description
Backing
Indicates that the leak detector is momentarily backing the foreline of the
high vacuum pump during an extended rough period. Backing occurs if the
roughing time is greater than 60 minutes or if the turbo pump is not ready.
Both Filaments/
No Emission
Indicates that no filament emission is detected. This can result from a PCB or
cable problem, or burned out filaments.