122770 06 18-09-2007 27
Likely cause: Solution:
Defect heatpipe.
Set the calibrator to –90°C, wait until
temperature has reached –90°C (or lowest
possible temperature) and measure
potentials between PIN1 and PIN3 on
connector CN103 on Power PCB.
A temperature difference between the two
sensors of 1°C equals a voltage difference
of approximately 40µV.
If the difference is more than 200µV (5°C),
the heat pipe is defect.
Replace cooling unit or return calibrator to
AMETEK Denmark A/S for maintenance
and refilling.