Cannon Instrument CMRV-5000 - Manual (Page 42)

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CANNON ® Mini-Rotary Viscometer CMRV-5000 Instruction & Operation Manual
Version 1.0b—August, 2011; CANNON ® Instrument Company
2139 High Tech Road • State College, PA • 16803 • USA
Cell calibration procedure
Calibration standards CANNON ® viscosity standard N105B is recommended for calibration
at -20°C and -25°C. This calibration is required for running ASTM
profiles included with the software. At -20°C, N105B has a nominal
viscosity of 30,000 cP (mPa·s). At -25°C, N105B has a nominal viscos-
ity of 56,600 cP (mPa·s).
CANNON ® Instrument Company can furnish viscosity standards for a
variety of temperatures and viscosities. The CMRV-5000 can be cali-
brated over the viscosity range of 1 to 99,999 cP (mPa·s).
After you have prepared the CMRV-5000 for the calibration run (see
Chapter 6) follow the procedure below to calibrate the CMRV.
Preparing the cells
Introducing sample
1. Place 10 ml of the calibration standard into each of the cells (see
photo).
2. Carefully place the rotors in their corresponding viscometric cells,
making sure that the rotor tip at the bottom of the shaft slides into the
recess at the bottom of the cup. Do NOT drop the rotors into place.
3. Secure each rotor in position with a rotor pin, and make sure that the
rotor locking pin is in the raised position. Install cell caps (see
photo).
Winding rotors 4. To wind the rotors in preparation for the cell calibration, slide the
pulley-wheel assembly along the track until the pulley is aligned
with the rotor to be wound. Use the engraved lines on the slide bar as
a guide to determine the proper position of the left side of the pulley-
wheel block.
5. Place the loop of a thread over the left end of the crossbar at the top
of the rotor shaft.
6. Pass the free end of the thread (the end with the plastic ring) over the
pulley-wheel and allow it to hang freely in front of the viscometer.
While holding the rotor motionless, hook a light weight, such as a
large paper clip, on the plastic ring to apply slight tension to the
thread.
7. Guiding the thread with your finger, turn the rotor clockwise to wind
the thread above the crossbar until the knot in the loop has been
wound around the rotor shaft. Then pass the thread below the cross-
bar and continue turning the rotor clockwise (as viewed from above)
to wind 20 closely spaced turns of thread around the shaft below the
crossbar without overlapping the turns. About 200 mm (8 inches) of
thread will remain. Place this remaining length of thread over the
upper bearing support plate so it hangs to the rear of the viscometer
and secure the rotor in place by lowering the rotor locking pin over
the rotor crossbar (see figure and photo, next page). You may need to
turn the rotor slightly to align the crossbar with the locking pin.
Unstrung rotor
wilth cell caps
installed