Advanced Instruments 3900, Service Manual

Page: 23 / 184

23
Daily
Perform calibration and repeatability tests to
keep your 3900 in peak condition. Readings
each day on separate aliquots of the same
standards should not deviate beyond the
repeatability and drift limits indicated in the
product specifications.
As required, replace:
• Probe wipers: The probe wiper sponges
should be replaced when they begin to
appear dirty (about every 50 tests).
• Drip catcher sponge: The drip catcher
sponge should be replaced when it
becomes dirty, worn or ineffective.
• Heat-transfer fluid: Because heat transfer
fluid will evaporate from the well and
droplets will cling to the sample tubes as
they are removed, the heat transfer fluid
should be drained and replaced at least
every two months, as follows:
1. Connect the quick-connect connector
and short length of tubing supplied with
the 3900 to the reservoir drain port in
the back panel of the instrument.
2. Place a container under the tubing to
catch the draining heat transfer fluid.
3. Press and hold in the reservoir pump
pushbutton for a few moments to pump
the heat transfer fluid remaining in the
system out into the container under the
reservoir drain tubing.
4. Disconnect the quick-connector and
dispose of the drained fluid.
5. Refill the reservoir with heat transfer
fluid as instructed in Chapter 1, User’s
Guide.
NOTE
When the reservoir is not
completely empty, using the
reservoir status SETUP menu
item will provide fluid-level
information to facilitate this
process and help avoid over-
filling the reservoir.
Monthly
Clean the air filters monthly and replace as
necessary. A dirty filter affects the ability of
the fan to cool internal components; a rise in
internal temperature may adversely affect
reliability.
The Advanced ® Model 3900 Service Manual
Maintaining the Instrument