Cannon Instrument CMRV-5000 - Manual (Page 62)

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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
NOTE Most commercial oils do not have a yield stress when tested as specified
by the SAE J300 Viscosity Classification.
For the complete, definitive description of the ASTM D 4684 method,
see the provided Standard Test Method for Determination of Yield Stress
and Apparent Viscosity of Engine Oils at Low Temperature, Designation:
D 4684, also available in the Annual Book of ASTM Standards, Volume
05.03.
NOTE Nothing in this manual is intended to supersede the provisions of the
ASTM test method.
The cooling cycles used in the ASTM D 4684 test method are sometimes
referred to as the TP-1 cycles. For details, see ASTM D 4684 and
Henderson, K. O., Manning, R. E., May, C. J., and Rhodes, R. B., “New
Mini-Rotary Viscometer Temperature Profiles That Predict Engine Oil
Pumpability,” SAE Paper No. 850443.
Required test time The ASTM D 4684 temperature program (profile) requires 45 to 54
hours to complete, depending on the final test temperature. Additional
time is required to perform yield stress and apparent viscosity measure-
ments.
ASTM D 3829 method
For the complete, definitive description of this method, see the provided
Standard Test Method for Predicting the Borderline Pumping Tempera-
ture of Engine Oil, Designation: D 3829, also available in the Annual
Book of ASTM Standards, Section 5, Volume 05.03.
NOTE Nothing in this manual is intended to supersede the provisions of the
ASTM test method.
ASTM Method D 3829 offers the option of reporting that the BPT
(borderline pumping temperature) is below a certain temperature. The
temperature control profiles for the CMRV-5000 are designed to run the
test at the limiting BPT for each viscosity grade. Thus, viscosity or yield
stress values must be below the critical values for an oil to be acceptable.
The temperature profile for this method consists of a 2-hour soak at 80°C
± 3°C, a 10-hour nonlinear cool-down to the test temperature, and a 6-
hour soak at the test temperature. The entire temperature profile, up to
the point of measuring yield stress and viscosity, requires about 18.5
hours.
ASTM D 6821 method
For the complete, definitive description of this method, see the provided
Standard Test Method for Low Temperature Viscosity of Drive Line
Lubricants in a Constant Shear Stress Viscometer, Designation: D 6821.
NOTE Nothing in this manual is intended to supersede the provisions of the
ASTM test method.