Model 979 Series Helium Mass Spectrometer Leak Detector
DRAFT 9/15/03
1-13
➀
Leak Rate Display
The large bar graph displays the leak rate in one of two forms:
❑
A mantissa on the bar and a numerical exponent
❑
Just the bar as a logarithmic bar graph display
The label for the bar graph changes to indicate the current mode of
operation.
➁
Pressure Displays
Two smaller bar graphs display the pressures in the spectrometer
tube and the test port. The small bar graphs change color to
indicate more or less favorable conditions.
➂
Audio Volume
Control
A pair of buttons are provided to change the volume level of the
audio leak rate indication.
➃
Sniffer On/Off
The SNIFFER ON/OFF button toggles the 979 into and out of
SNIFFER mode. The LED illuminates when SNIFFER mode is
enabled.
➄
Vent
The VENT button advances the 979 to the vented state. The
LED indicator illuminates while the 979 is in the vented state.
➅
Test/Hold
When in VENT or HOLD, pressing the TEST/HOLD button
automatically advances the 979 through roughing, then through
the various test states, depending on the achievable test port
pressures and leak rates. The green LED above the button illumi-
nates when the 979 is in a test state. When in TEST, pressing the
TEST/HOLD button automatically advances the 979 to the HOLD
state. The yellow LED below the button illuminates when the 979
is in the HOLD state.
➆
Zero
The ZERO button is functional only in the test state. The ZERO
function zeros the leak rate in the current valve test state. The LED
illuminates while the zero function is taking place.
➇
Read Standard Leak The READ STANDARD LEAK button is functional only in the test
state. This function is used to verify calibration by exposing the
optional internal calibrated leak or the external calibrated leak to
the system.
➈
Calibrate
The CALIBRATE button initiates the calibrate function using either
the optional internal calibrated leak or an external leak in the test
port, as dictated by the parameters set on the Calibrated Leak
Set-Up screen (see Section 2.6.1 “Calibrated Leak Set-Up” on
page 2-14). The LED illuminates to indicate that calibration is
taking place.
➉
Key Switch
This three-position key switch, SET-UP/RUN/SERVICE, allows for
access and control of operational parameters, as well as service
related functions.
Summary of Contents for 979 Series
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