Maintaining Your Instrument
Static Electricity Precautions
Thermo Scientific
Nicolet iS20 User Guide
21
Static Electricity Precautions
Critical components in your instrument can be permanently damaged by static electricity. To
help prevent such damage, follow these recommendations:
Maintaining Detector Dewars
If your instrument has a cooled detector, it will include a detector dewar. With proper care, a
detector dewar should maintain its insulating vacuum for many years. If the vacuum leaks, the
insulation will lose effectiveness and the following symptoms may occur:
• Liquid nitrogen boils off much faster than usual.
• The outside of the dewar stays cold more than 30 minutes after filling and may feel damp
or become frosted.
• Water and atmospheric contaminants condensing on the detector window show up in
spectra as unwanted peaks.
NOTICE
• Before you disconnect the power supply, always discharge any static electricity you
may have accumulated by touching the metal base of your instrument.
• Do not touch any printed circuit board in the instrument (such as the circuit board
on the detector).
• Do not remove replacement components from their protective packaging until you
are ready to install that component in the instrument.
NOTICE
If your instrument shows any of these symptoms, the detector dewar may have
a vacuum leak. Contact us immediately for assistance. Leaving internal detector elements
exposed to atmospheric pressure can permanently damage them.
Note
You can restore the vacuum in a detector dewar if you have the proper equipment.
The vacuum must be pumped to approximately 5x10
-8
torr. A special evacuation valve for
pumping out dewars is available from us. To order a dewar evacuation valve, contact us.
