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Chapter 7 - Safety Procedures and Troubleshooting
Safety Procedures
CAUTION, do not operate laser with instrument cover off.
This unit is equipped with a Laser safety interlock system. Whenever the cover is
removed, 2 mechanical switches are activated. 1 turns off the AC power to the laser
control module that supplies power to the laser. The second one disables the laser enable
line. Under no circumstances should the user disable these Safety interlocks. The laser
should remain off any time the cover is removed. All safety precautions noted on caution
labels should be adhered to.
Troubleshooting
Unit has low Laser Reference voltage
•
Ensure VI is running and Laser Current is on and Laser temperature is at the
correct value
•
If laser current is on and the Scatter and/or Reference value are low,
perform the Cleaning the laser optics procedure listed below
•
Contact the service representative for further assistance
Unit will not zero count
•
Install supplied zero count filter to the inlet of unit and run 5 minute
samples, load a bin map of 55 to 255nm this will help to determine if the
unit has a leak or it is counting noise.
•
Noise will typically appear in only the first few channels, if the unit
has a leak, typically there will be an ambient looking distribution.
o
If the unit appears to have a leak, check any external
connections between the unit and the filter and rerun test
o
If unit appears to have noise counts, Check the reference and
Scatter level, clean optics if necessary
o
If acceptable background zero count level cannot be attained,
Contact the service representative for further assistance.
Cleaning the Laser Optics
Under normal operating conditions the laser optics should not need to be cleaned very
often. If the unit is turned on and off, or moved from place to place frequently, the
duration between cleanings may be reduced. There are 2 monitors of the intra-cavity
power of the laser, the Reference and the Scatter voltages. The initial values of these
can be found on the sheet at the last page of this manual. If either one or both of them
drop by 25%, the Laser optics will need to be cleaned. Follow the steps below:
NOTE: Before removing the instrument cover, turn off the laser by depressing the “on”
button for the Laser current on the laser control page.
•
After ensuring laser current is off, remove the 14 Phillips head screws holding the
cover on. Lift the cover straight up until it clears the unit.
