CANNON Instrument Company® | Advanced Setup
43
CAV® 4.2 Operation Manual
Advanced Setup
Note:
You must be logged into the CAV4.2 GUI or VISCPRO as a manager
in order to perform advanced procedures.
Calibrate Viscometer Tube (VISCPRO II)
Viscometer tube calibration values are associated with specific temperatures, so calibration must
be performed when operating a CAV 4.2 bath at a new temperature. Once a tube is calibrated at a
particular temperature, the C and E constants are saved by the instrument and will be recalled if
that tube is set to run at that temperature again.
1.
Assemble a set of standard oils with known kinematic viscosities. Use at least different two
standards for each bulb to be calibrated. The CAV 4.2 is designed to run "thin" standards (those with
viscosities less than 10X the lower limit of the viscometer tube) in two bulbs, while "thick" standards
(those with viscosities greater than 10x the lower limit of the viscometer tube) run in only the lower
bulb.
2.
Follow the procedures in
Run a sample test
to prepare, load, and run all of the calibration standards
as method
Verify Known KV
.
3.
When all tests have completed, from the
VISCPRO II Menu
, select
Configure > [
instrument group
]
> [
instrument
] > Tube Calibration
. The
Tube Calibration
window opens.
4.
Select the tube and the bulb to calibrate.
5.
Select the date range from which to retrieve appropriate test data.
6.
Select the sample entries to use for calibration. You must select at least two entries or the software
will not recalculate the constants.
•
Shift-left-click
—to select a contiguous range of entries.
•
Ctrl-left-click
—to select multiple entries.
7.
Click
Calculate
new constants. The new C and E constants display in their respective fields.
•
Evaluate the accuracy of the new calibration constants for each standard by comparing the
Known Viscosity
with the
Calculated Viscosity
. This difference is displayed as a percentage in
the
% Difference
column. You can repeat the calibration by selecting other sample entries.
•
Check
Limit E Constant
before calculating constants to limit the E constant to no more than
10000.
8.
When the new calibration constants are acceptable, click
Update bulb
to save the C and E constants
and calibration data to the local database and update the C & E constants in the registry of the CAV
4.2.
