Cannon Instrument CAV-2000 - Manual (Page 39)

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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
9. Select the date range for acceptable calibration data by using the No
older than [x] days spin controls to set the date search param-
eters (if “1” is selected, only data from the standards run on yester-
day and today’s date will be listed). Any check standards from the
time frame you specified which are appropriate for calibration
calculations will appear in the window list box.
Selecting samples
10. Select (or deselect) the specific sample entries you desire to use for
calibration from the displayed list by clicking on them. To select a
range of samples, highlight the first sample and click on the last
sample while simultaneously pressing the S key. To select
several individual samples for calculation, hold down the C key
and click on each of the desired samples.
NOTE You must select at least two entries or the software will not recalculate
the constants.
11. When the desired samples have been selected, click on Calculate
New Constants. The new constant(s) for that bulb, C and E, will be
displayed in their respective fields at the bottom of the window.
You may evaluate the accuracy of the new calibration constants by
comparing the known viscosity for the standard with the calculated
viscosity for each standard selected for the new calibration. This
difference is displayed as a percentage in the last column (% Diff) of
the updated sample list box.
12. If the new calibration constants are acceptable, click on Update bulb
to save the constants for the current instrument. If the difference is
not within acceptable limits, refer to Chapter 5 for CAV maintenance/
service information.
NOTES Once the Update bulb button is pressed, the updated calibration con-
stants are associated with the selected instrument, and will remain the
same regardless of the instrument configuration defined for that instrument.
You must click Update bulb before changing bulbs if you wish to save the
new calibration constants for that bulb.
13. Repeat steps 8-12 for all the viscometer tubes and timing bulbs.
When the proper constants for all the timing bulbs of all the viscom-
eter tubes have been determined, close the Calibration window.
14. Test several standards to verify a successful calibration.
Saving a calibration
When calibration is complete, the calibration information is saved to the
current instrument configuration and will be displayed in the Tray
Settings: Tube and Bath window (see page 45). This calibration