but appropriately rated fuses must be installed. Use 5 × 20mm,
250V, time delay (Type T) 1.25-Amp fuses.
4. Re-install the fuse holder into the back of the instrument.
5. Reconnect the power cord and switch the power switch to the on
position. The instrument should start up as normal.
Chamber cleaning
The cooling chamber and probe are easy to keep clean and dry by faith-
fully following the operating instructions for cleaning the freezing
chamber after each test. If traces of calibrators, controls or biological
samples are left in the sample chamber, however, the task will be more
difficult and damp cleaning will probably be required. Two indicators
that damp cleaning may be required are:
• The instrument has been in use but no clean, dry chamber cleaner is
found in the sample port, and successive results on aliquots of the
same sample indicate chamber contamination (the first aliquot read-
ing is very high, and subsequent readings are progressively lower).
• “Sample Pre-freeze” errors begin to occur quite frequently.
33
Troubleshooting & Service
Figure 8: Fuse Replacement
FUSE HOLDER