INFICON UHV Bakeable Sensor - Manual (Page 45)

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UHV Bakeable Sensor Operating Manual
Chapter 5
Troubleshooting
5.1 Troubleshooting Tools
If the UHV Bakeable Sensor fails to function, or appears to have diminished
performance, diagnose the sensor using one or more of the following:
 Symptom, Cause, Remedy chart (see section 5.1.1 )
 Diagnostic Tools (see section 5.1.2 on page 5-4 )
 Digital Multimeter (see section 5.1.3 on page 5-5 )
5.1.1 Symptom, Cause, Remedy
The Symptom, Cause, Remedy chart can help identify the causes of, and solutions
to, sensor problems and related issues (see
Table 5-1 ).
Table 5-1 Symptom, Cause, Remedy
SYMPTOM CAUSE REMEDY
Large jumps of thickness
reading during deposition. Mode hopping due to damaged
or heavily damped crystal. Replace the crystal.
Crystal is near the end of its life.
Scratches or foreign particles on
the crystal holder seating
surface. Clean or polish the crystal
seating surface of the crystal
holder (refer to
section 4.3.2 on
page 4-6 ).
Uneven coating. Mount the sensor with the
crystal face perpendicular to the
evaporant stream (refer to
section 2.2 on page 2-4 ).
Particles on the crystal. Remove source of particles and
replace the crystal.
Crystal ceases to oscillate
during deposition before it
reaches its “normal” life. Crystal is being hit by small
droplets of molten material from
the evaporation source. Use a shutter to shield the
sensor during initial period of
evaporation.
Move the sensor farther from the
source.