ASTM D6896-12

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D6896 − 03 (Reapproved 2007) D6896 − 12
Standard Test Method for
Determination of Yield Stress and Apparent Viscosity of
1
Used Engine Oils at Low Temperature
This standard is issued under the fixed designation D6896; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Scope*
1.1 This test method covers the measurement of the yield stress and viscosity of engine oils after cooling at controlled rates over
a period of 43 or 45 h to a final test temperature of -20 or -25°C. The precision is stated for test temperatures -20 and -25°C. The
-1
viscosity measurements are made at a shear stress of 525 Pa over a shear rate of 0.4 to 15 s . This test method is suitable for
measurement of viscosities ranging from 4000 mPa·s to >400 000 mPa·s, and is suitable for yield stress measurements of 7 Pa to
>350 Pa.
1.2 This test method is applicable for used diesel oils. The applicability and precision to other used or unused engine oils or
to petroleum products other than engine oils has not been determined.
1.3 This test method uses the millipascal second (mPa·s) as the unit of viscosity. For information, the equivalent centipoise unit
is shown in parentheses.The values stated in SI units are to be regarded as standard. No other units of measurement are included
in this standard.
1.3.1 Exception—This test method uses the SI based unit of milliPascal second (mPa·s) for viscosity which is equivalent to
centiPoise (cP).
1.4 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
2.1 ASTM Standards:
D3829 Test Method for Predicting the Borderline Pumping Temperature of Engine Oil
D4684 Test Method for Determination of Yield Stress and Apparent Viscosity of Engine Oils at Low Temperature
D5133 Test Method for Low Temperature, Low Shear Rate, Viscosity/Temperature Dependence of Lubricating Oils Using a
Temperature-Scanning Technique
E1137 Specification for Industrial Platinum Resistance Thermometers
3. Terminology
3.1 Definitions:
3.1.1 apparent viscosity—viscosity, n—the determined viscosity obtained by use of this test method.
3.1.2 Digital Contact Thermometer (DCT), n—an electronic device consisting of a digital display and associated temperature
sensing probe.
1
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.07 on
Flow Properties.
Current edition approved Nov. 1, 2007Nov. 1, 2012. Published January 2008April 2013. Originally approved in 2003. Last previous edition approved in 20032007 as
ε1
D6896D6896–03(2007).–03 . DOI: 10.1520/D6896-03R07.10.1520/D6896-12.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3.1.2.1 Discussion—
This device consists of a temperature sensor connected to a measuring instrument; this instrument measures the temperature-
dependent quantity of the sensor, computes the temperature from the measured quantity, and provides a digital output or display
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D6896 − 12
of the temperature, or both. The temperature sensing probe is in contact with the material whose temperature is being measured.
This device is sometimes referred to as a digital thermometer.
3.1.3 Newtonian oil or fluid—fluid, n—an oil or fluid that at a given temperature exhibits a constant viscosity at all shear rates
or shear stresses.
3.1.4 non-Newtonian oil or fluid—fluid, n—an oil or fluid that at a given temperature exhibits a viscosity that varies with
changing shear stress or shear rate.
3.1.5 shear rate—rate, n—the velocity gradient in fluid flow. For a Newtonian fluid in a concentric cylinder rotary viscometer
in which the shear stress is measured at the inner cy
...