ASTM D6895 Standard Test Method for Rotational Viscosity of Heavy Duty Diesel Drain Oils at 100°C
1. Scope
1.1 This test method covers the determination of the rotational viscosity and the shear thinning properties of heavy duty diesel engine drain oils at 100°C, in the shear rate range of approximately 10 to 300 s(-1), in the shear stress range of approximately 0.1 to 10 Pa and the viscosity range of approximately 12 to 35 mPa·s. Rotational viscosity values can be compared at a shear rate of 100 s(-1) by this test method.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D5967 Test Method for Evaluation of Diesel Engine Oils in T-8 Diesel Engine
D6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measurement System Performance
3. Terminology
3.1 Definitions ofTerms Specific to This Standard:
3.1.1 maximum point time - instrument setting that limits the amount of time the instrument will maintain a constant shear stress or shear rate before accepting the value as the equilibrium value.
3.1.2 rate index - the exponent, c, in these expressions relating shear rate and shear stress:
shear stress = b(shear rate)c
ln(shear stress) = lnb + cln(shear rate)
3.1.2.1 Discussion - A rate index of c = 1 signifies Newtonian fluid behavior. Values less than one indicate increasing non-Newtonian, shear thinning behavior.
3.1.3 rotational viscosity - the viscosity obtained by use of this test method.
3.1.4 VIS100 DEC - rotational viscosity at shear rate of 100 s(-1), decreasing shear stress or shear rate sweep.
3.1.5 VIS100 INC - rotational viscosity at shear rate of 100 s(-1), increasing shear stress or shear rate sweep.
