Advanced Instruments 3900, User Manual

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55
Routine maintenance
Daily:
You should confirm the calibration and repeatability to ensure your
osmometer is in peak condition. Instrument accuracy is determined by
comparing your results on precisely known standards and/or controls
with their specified values.
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 push button 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
Installation & Setup.
NOTE When the reservoir is not completely empty, using the reser-
voir status SETUP menu item will provide fluid-level infor-
mation to facilitate this process and help avoid over-filling
the reservoir.
Troubleshooting & Service