Advanced Instruments 3900, Руководство пользователя

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The Advanced
®
Osmometer Model 3900 User’s Guide
12. Select Range
The Model 3900 can operate in “Low” or “High” range depending
upon the expected sample result range. “Low Range” optimizes
operation for results between 0 and 1550 mOsm - “High Range”
between 1450 and 4000 mOsm. Because most applications do not
require High Range operation, all Model 3900 osmometers default
to Low Range . High Range operation may be selected by the fol-
lowing procedure:
At “
Select Range ”, press START. “ [low]* range >[high] ” will be
displayed and the high range may be selected. The current setting is
indicated by the symbol “ * ”. Press < or > to toggle between the low
and high ranges.
If the low range is selected, you will be prompted to select glass or
plastic sample tubes. It is important that you make this selection as
internal operating parameters will be revised to optimize the instru-
ment’s performance based upon type of sample tube.
Press ENTER to store to store the new setting (or STOP to restore
the previous setting).
Check the calibration; recalibrate as necessary. Both ranges were
calibrated at the factory.
If switching from low to high range, the Model 3900 may need time
to adjust the cooling system for optimal operation. This procedure
may take 2-3 minutes. To avoid delays in operation, the operator
may wish to observe the equilibrium period and make sure calibra-
tion is successfully started before leaving the Model 3900 to run
automatic calibration.
13. Set “Buzz” Point
This menu item enables setting the temperature at which crystalliza-
tion is induced by the freeze pulse (buzz) in each range.
Most freezing point osmometers supercool all samples in the 0-
1550 mOsm range to approxi mately 3000 on the mOsm scale; the
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