INFICON UHV Bakeable Sensor User Manual
Page 47

5 - 3
PN
07
4-
15
4N
UHV Bakeable Sensor Operating Manual
Thermal instability: large 
changes in thickness reading 
during source warm-up (usually 
causes thickness reading to 
decrease) and after the 
termination of deposition 
(usually causes thickness 
reading to increase).
Excessive heat applied to the 
crystal.
If heat is due to radiation from 
the evaporation source, move 
sensor farther away from source 
and use Low Thermal Shock 
crystals (PN SPC-1157-G10) for 
better thermal stability. 
If the source of crystal heating is 
due to a secondary electron 
beam, use a sputtering sensor.
No cooling water.
Water flow rate is low.
Water temperature too high.
Check cooling water flow rate.
Heat induced from electron flux. Use sputtering head for
non-magnetron sputtering.
Poor thickness reproducibility.
Erratic source emission 
characteristics.
Move sensor to a different 
location.
Check the evaporation source 
for proper operating conditions.
Ensure relatively constant pool 
height and avoid tunneling into 
the melt.
Use multiple sensor option if 
available on controller.
Material does not adhere to the 
crystal.
Check the cleanliness of the 
crystal.
Use gold or silver or alloy 
crystals, as appropriate.
Evaporate an intermediate layer 
of proper material on the crystal 
to improve adhesion. 
Table 5-1 Symptom, Cause, Remedy (continued)
SYMPTOM
CAUSE
REMEDY
