Cannon Instrument CMRV-4500 - Manual (Page 73)

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CANNON ® Mini-Rotary Viscometer CMRV-4500 Instruction & Operation Manual
Version 1.1e—October, 2011 • CANNON ® Instrument Company
2139 High Tech Road • State College, PA • 16803 • USA
10. If testing viscosity for the sample, follow the directions for viscosity
testing (see Measuring Apparent Viscosity, next page).
11. Repeat steps 1-10 to perform yield stress/viscosity tests for all
remaining cells to be tested in order from left to right.
Notes on yield stress testing
Step 9 (see previous section) is required for ASTM D 3829.
The ASTM D 4684 method is a pass-fail method for fresh oils. If the
rotor fails to move with the weight of the 10-gram hook-cage, the oil
has failed the test. However, the MRVW program permits adding of
additional weights. If this alternate method is preferred, continue with
the procedure as described in step 9. Otherwise, click the
Abort Test
button to abort yield stress testing on that cell.
NOTE Do not abort CMRV temperature control until you have finished all yield
stress and viscosity tests for the cells.
Pulley-wheel motion is detected by the digital-optical sensor. Ad-
equate rotor movement is defined as 13° of rotation for ASTM D
4684 and ASTM D 6821 (This is equivalent to 3 mm of motion by
the crossarm). For ASTM D 3829, 10° of rotation is required.
If yield stress testing on a cell is aborted before adequate rotor
movement is detected, the resultant calculated yield stress will be
based on the highest weight used. For example, if the operator aborts
a yield stress calculation after testing with a total of 30 grams with no
rotor movement, the CMRV software will report yield stress greater
than 105 Pascals (Y>105).
Measuring apparent viscosity
After the yield stress test has concluded, you may measure apparent
viscosity using the procedure below:
1. Place the pulley-wheel in line with the appropriate viscometric cell
and place the rotor thread over the pulley-wheel.
NOTE ASTM methodology requires testing the samples in sequence from left to
right.
2. Ensure that a Sample ID has been entered for each sample. Then
click for the desired sample. OR use the Tab key to highlight
the desired viscosity test icon and then press R. The Viscosity
LED (light-emitting diode) on the CMRV-4500 will glow and the
Start Test button will begin flashing rapidly.
3. Carefully place the large hook-weight on the end of the thread (see
photo, next page), supporting the weight with your hand to prevent
rotation of the rotor.