Varian 990 dCLD II, Operation Manual

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Model 990 dCLD II Component Leak Detector
6-7
The typical values for these parameters’ voltage readings should change as follows:
9. If all values are more than 20 percent lower than the values above, or if any two values
are equal, disconnect the spec tube block connector and check the ion source for shorts
using an ohm meter. If the Ion Source is not shorted:
a. Replace the 990 dCLD II control unit to determine if the control unit is defective.
b. Finally, replace the turbo spec tube cable to determine if it has failed.
10. If EMISSION I is zero, the selected filament in the Ion Source is broken or the Ion Source
is defective. Change to the other filament using the MANUAL TUNING screen, refer to
Section 4.7.2 “Manual Tuning” on page 4-19, or replace the ion source, see Section 5.5
“Ion Source Replacement Outside of Spectrometer Tube Overhaul” on page 5-19.
11. Has the spectrometer tube been serviced lately? If so, refer to Section 5.3, “Spectrometer
Tube Overhaul” to verify that:
a. The ground slit plate has been properly positioned (Figure 5-21 on page 5-17).
b. The ion source is correctly aligned (Figure 5-21 on page 5-17).
c. That the magnet pole piece inserts are fully inserted and secured in place with set
screws.
If there is still no helium response, call Varian Customer Service at 1-800-8VARIAN
(1-800-882-7426).
Parameter Voltage Parameter Voltage
ION 242.9 GAIN 1.0
VAR FOCUS 202.4 EMISSION I 1.110
REPELLER 388.1