Model 979 Series Helium Mass Spectrometer Leak Detector
DRAFT 9/15/03
2-9
2.4.2 Test Port Pressure
The Test Port Pressure value displayed on the touch panel Home screen represents the test
port pressure as measured by a thermocouple device mounted on the valve block just
below the test port. The pressure transducer and associated electronics provide reliable and
repeatable measurements, protecting the leak detector from damage due to over-pressure
conditions. The test port pressure gauge is not intended to provide precise, absolute pres-
sure measurements. Use an external pressure transducer if the test process requires accurate
monitoring of the test object pressure. The units for the measurements are user selectable
from the Units Set-Up screen (Section 2.7.1 “Units Set-Up” on page 2-28).
2.4.3 Leak Detector Status
Leak Detector Status (not shown in Figure 2.4) is displayed just below the test port pressure
reading and indicates the current operating state of the 979. The normal operating states are
detailed in Table 2-2 on page 2-10.
2.4.4 Leak Detector Condition
The Leak Detector Condition (not shown in Figure 2.4) is displayed below the Leak Detec-
tor Status and indicates the current condition of the leak detector. Under normal operating
conditions this line is blank. The 979 leak detector conditions are detailed in Table 2-3 on
page 2-10.
2.4.5 Reject Status Indicator
A REJECT status indicator displays below the Leak Detector Condition on the left-hand cen-
ter of the Home screen when any of the four independent set points are enabled and have
been activated (see Section 2.6.2 “Reject and Audio Set Points” on page 2-16). If all set
points are disabled or are not active, then this indicator is not present.
2.4.6 SYS INFO and MENUS Touch Screen Boxes
Two touch screen boxes are displayed on the bottom of the Home screen. Touch the
SYS INFO box on the left-bottom of the Home screen to display the System Info screen,
which is discussed in the next section.
Touch the MENUS box on the right-bottom of the Home screen to display the First Menu
Selection screen. The First Menu Selection screen is discussed in Section 2.6 “First Menu
Selection Screen” on page 2-14.
Summary of Contents for 979 Series
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