Princeton Instruments NIRvana-LN, User Manual, Page: 88 / 122

88 NIRvana
™
-LN System Manual Issue 4
10.3 Cooling Troubleshooting
This section provides recommended troubleshooting guidelines for cooling-related issues.
10.3.1 Temperature Lock cannot be Achieved or Maintained.
Possible causes could include:
•
The vacuum has deteriorated and needs to be refreshed.
• The target array temperature is not appropriate for the particular detector and array.
10.3.2 Detector loses Temperature Lock
The internal temperature of the detector is too high. This might occur if the operating
environment is particularly warm, if you are trying to operate at a temperature colder or
warmer than the specified limit, or if there is not enough LN in the Dewar. Refill the Dewar
and verify that temperature lock can now be achieved.
If the problem persists, contact Customer Support for further instructions. Refer to
Contact
Information on page 120 for additional information.
10.3.3 Gradual Deterioration of Cooling Capability
With time, there will be a gradual deterioration of the detector’s vacuum. This, in turn, will
eventually affect temperature performance and it may no longer be possible to achieve
temperature lock at the lowest temperatures. In the kind of low-light applications for which
cooled array detectors are so well suited, it is highly desirable to maintain the system’s
temperature performance because lower temperatures provide less thermal noise and better
signal-to-noise ratio.
Vacuum deterioration occurs primarily as a result of outgassing of components in the
vacuum chamber. Because outgassing normally diminishes with time, the rate of vacuum
deterioration in new detectors will be faster than in old ones. When the detector no longer
maintains an acceptable cold temperature, contact Customer Support to make arrangements
to return the detector to have the vacuum restored. Refer to
Contact Information on
page 120 for additional information.
WARNING!
Do not open the vacuum valve under any circumstances. Opening the
vacuum valve will void the warranty.