Varian 990 dCLD II, Operation Manual

Page: 77 / 162

Model 990 dCLD II Component Leak Detector
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The READ STANDARD LEAK button is functional only when the key switch is in
the SET-UP or SERVICE positions and when PARALLEL ENABLE is not asserted.
Press the READ STANDARD LEAK button to display the value on the bar graph,
and on the System Information screen allowing verification of 990 dCLD II cali-
bration. When the system is in READ STANDARD LEAK mode, its LED indicator
lights and STD LEAK is displayed on the HOME screen operating state line.
After verifying the 990 dCLD II calibration, press the READ STANDARD LEAK
button to turn it off.
The CALIBRATE button is functional only when the key switch is in the SET-UP
or SERVICE positions, and when PARALLEL ENABLE is not asserted.
Press the CALIBRATE button to perform an automated calibration based upon
the parameters set on the Calibrated Leak Set-Up screen (Section 4.6.1
“Calibrated Leak Set-Up” on page 4-13). The calibrate indicator LED lights while
calibration is taking place and CALIBRATING is displayed on the HOME screen
operating state line.
The Audio leak rate indication volume is controlled by the two buttons labeled
HI and LOW and with up and down arrows. Press the
HI arrow button to
increase the volume of the tone. Press the LOW arrow button to decrease the
volume of the tone.
When the leak rate bar graph display is set to LINEAR mode (see “Output
Control Setup” on page -16), the audio signal increases from a low to high pitch
as the leak rate increases within each decade. The pitch cycles low to high as it
passes through each decade.
When the leak rate bar graph display is set to LOG mode (see “Output Control
Setup” on page -16), the audio signal increases from a low to high pitch as the
leak rate increases through the entire bar graph scale.
If it is set up before PARALLEL ENABLE is asserted, the audio signal is operable.
The set point must be set before PARALLEL ENABLE is asserted.