Model 979 Series Helium Mass Spectrometer Leak Detector
DRAFT 9/15/03
2-21
2.6.5.1 Range Stop and Manual Range Set-Up and Control
RANGE STOP
The RANGE STOP feature configures the 979 so that it only
auto-ranges down to the pre-selected decade entered in the range
stop variable field. For example, if range stop was enabled and the
range stop setting was 10-07, then the most sensitive range that the
leak detector displays is full-scale 10
−
7
atm cc/sec.
This feature is useful when a product specification is more
than one decade less stringent than the actual sensitivity of the
leak detector. If the leak detector is capable of displaying full
scale 10
−
9
atm cc/sec but the test specification is only in
the 10
−
7
atm cc/sec range, then setting the range stop to
10-08 atm cc/sec reduces the test cycle time by eliminating
the need for the leak detector to reach its most sensitive scale
during each test cycle.
To enable or disable RANGE STOP, touch the ON or OFF box
under the desired function.
MANUAL RANGE
The MANUAL RANGE feature configures the 979 so that it only
displays the pre-selected decade entered in the manual range
variable field. For example, if the manual range feature was
enabled and the manual range variable was set to 10-06, then the
leak rate decade displayed on the LED bar graph during testing will
be the 10-06 atm cc/sec range only. This feature is useful when the
test operator is only concerned with monitoring the leak rate mea-
surement within a single decade.
To enable or disable MANUAL RANGE, touch the ON or OFF box
under the desired function.
Summary of Contents for 979 Series
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