Cannon Instrument CMRV-5000 - Manual (Page 66)

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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
8. Place the loop of a thread over the left end of the crossbar at the top
of the rotor shaft.
9. 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.
10. 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
crossbar 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. You may need to turn the rotor
slightly to align the crossbar with the locking pin.
11. Repeat steps 8-10 for each of the remaining rotors/cells.
Plexiglas ® cover placement 12. Place the Plexiglas ®
cover in position
over the top of the
viscometric cells
(see photo). The
small hole which
allows the -46 to
30°C thermometer to
extend through the
cover should be on
the left when viewed
from the front of the
viscometer.
CAUTION If a thermometer is not in place during CMRV-5000 testing, you should
seal the thermometer opening in the Plexiglas
® cover, particularly when
the humidity of the ambient air is high. Otherwise, moisture may con-
dense and freeze on the top of the block.
13. CMRV users following the ASTM D 4684 or ASTM D 3829 meth-
odology should insert a flexible 3/16"-OD tube from their dry gas
supply and regulator through the dry gas purge in the Plexiglas
®
cover (Step 9.2.6 in the ASTM D 4684-98 method and step 9.1.6 in
the ASTM D 3829 method). The tubing may be removed, along with
the cover, prior to viscosity/yield stress testing.
14. Whatever the methodology, the purge should continue throughout the
temperature profile using dry gas at a flow rate between 20 and 30
milliliters per minute.
CMRV-5000 with rotors wound and
Plexiglas
® cover in place.