Advanced Instruments 4250, User Manual

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Monthly . Maintenance you should perform:
Clean or replace the air filter (Figure 5, item 7) monthly; replace as
necessary. A dirty filter affects the ability of the fan to cool internal
components; a rise in internal temperature may adversely affect relia-
bility.
Shutdown and storage
Overnight or weekend:
1. Rinse the probe clean with distilled water and wipe it dry.
2. Turn off the instrument, if desired.
3. Do not cover the instrument unless it is turned off.
One week or longer:
1. Rinse the probe clean with distilled water and wipe it dry.
2. Turn off the instrument.
3. Unplug the power cord from the wall outlet.
4. Cover the instrument.
Troubleshooting checks
Check operational requirements. If you are experiencing difficulties
with your instrument, first carefully review the operational requirements
listed in the product specifications and the recommended setup and oper-
ating procedures. Check the heat transfer fluid level. Make sure that the
heat transfer fluid pump is fully primed.
Check fuses. You will find the power switch and fuse holder beside the
power cord connector on the back panel of the instrument. Switch the
power switch to the off position and disconnect the power cord. Use a
small flat-bladed screwdriver or similar tool to pry out the fuse holder.
Visually check for a blown fuse. If there is any doubt, test the fuses with
a continuity checker or ohmmeter or simply replace them with new fuses.
Check probe and stir wire. Run the A/D Test and the Probe Bin Test to
evaluate the probe operation. Refer to the Mandrel, Probe, and
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Troubleshooting & Service