Viscometer tubes, Dual-solvent washing, Thermistor operation – Cannon Instrument miniPV-X User Manual
Page 82: Timing bulb determination
CANNON
®
miniPV-Series Automatic Viscometer with VISCPRO
®
Instruction & Operation Manual
Version 1.a— January, 2011;
CANNON
®
Instrument Company
2139 High Tech Road • State College, PA 16803 • USA
76
WARNING
Waste sample/solvents can present possible environmental and health
hazards. Dispose of all waste materials in accordance with environmental and
safety regulations.
Dual-solvent washing
For testing heavy or hard-to-clean materials,
CANNON
®
Instrument
Company recommends a dual-solvent washing system. The dual-solvent
washing process uses two different solvents. The first wash might
ordinarily use a heavy solvent to clean the sample residue out of the
viscometer tubes. The second wash might use a lighter solvent to remove
any remaining sample/solvent residue and dry the viscometer tube. Test
temperature(s) must be carefully considered when choosing solvents.
Dual-solvent action
To engage the dual-solvent washing, make certain that desired wash
options are selected in the VISCPRO
®
software for
Solvent A
(washing
solvent) and
Solvent B
(drying solvent). Follow the instructions in the
Installation section of this manual to correctly configure the instrument for
dual solvent operation.
Viscometer tubes
The miniPV Series is equipped with a borosilicate glass capillary viscom-
eter tube having a wide viscosity range. The upper viscosity limit is up to
100 times the lower viscosity limit, depending on the tube type. Each 100-
fold viscometer tube contains three thermistors used for sensing the level
of the sample within the tube.
Thermistor operation
The tube thermistor detects the change in thermistor temperature associ-
ated with the passing of the sample meniscus, and records the time
accurately to within one-hundredth (0.01) of a second.
Timing bulb determination
As the sample is drawn into the viscometer tube, the VISCPRO
®
soft-
ware automatically determines which timing bulb will be used to test the
sample.
The sample will be drawn into the bulb above the upper timing thermistor.
That bulb will serve as the overflow bulb for that particular test run.
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NOTE
The numbers listed in this table are approximations, not absolute values.