Cannon Instrument CAV-2000 - Manual (Page 54)

CANNON ® Automatic Viscometer Models CAV-2100 and CAV-2200 with VISCPRO ® Instruction & Operation Manual
Version 2g — May, 2009; CANNON ® Instrument Company
2139 High Tech Road • State College, PA 16803 • USA
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Constants The Tray Settings: Tube and Bath screen displays the calibration
constants (C and E) for each bulb of the viscometer tube. These values
cannot be edited from the Tray Settings . . . screen. For information on
determining bulb constants for viscometer tubes, see Calibration later in
this chapter.
NOTE When you have completed the configuration and saved the current tray
settings, you may wish to permanently store the current instrument
settings using the Save Instrument option from Main.
Tray Settings: Test
The Tray Settings: Test window is used to select parameters for CAV
sample testing. Each sample test is called a determination. Multiple
determinations are possible for a single sample. Comparisons of sample
results permit user regulation of test precision.
The Maximum Absolute Difference option permits you to input the
maximum acceptable deviation for multi-drop samples, expressed as the
difference in the sample drop times in seconds.
The Maximum % Difference option allows you to input the maximum
acceptable deviation for multi-drop samples expressed as a percentage
(.35 is the default percentage difference allowable). Values from 0.01 to
99.99 are acceptable. If the difference between test drop times is greater
than the acceptable deviation, the sample will be tested again until the
deviation in drop times is less than the Maximum % Difference, or until
the maximum number of determinations has been reached.
The Maximum Determinations option permits you to select from 1-20
iterations of the test using the same sample.
Tolerance parameters Determine if the tolerance for differences between sample run times
(determinability) is going to be decided by the absolute difference in drop
time values (in seconds) or by the percentage difference between the drop
times. Click on the appropriate check box to select your choice(s).
Enter the maximum acceptable difference in measured results when using
multiple determinations (the default percent difference value is 0.35
percent and the default absolute difference value is 0.2 seconds).
Use greater If both tolerance options are selected, the VISCPRO software will apply
both criteria unless the Use greater option is checked. If Use greater is
checked, then the software will apply the less exacting tolerance value
when calculating/evaluating test results.