5.1 The flow behavior of many fluids of interest is non-Newtonian in nature. Non-Newtonian behavior is best studied using rheometry apparatus. Nonetheless, estimations on non-Newtonian behavior may be made by recording viscosity at differing rotational speeds (or shear rates) using rotational viscometers.

5.2 The shear thinning index provides a tool for the estimation of the amount of non-Newtonian behavior.

5.3 The shear thinning index may be used in quality assessment, trouble shooting, specification acceptance, and research.

1.1 This test method describes the determination of the shear thinning index of a shear-rate dependent (non-Newtonian) fluid using a cylindrical rotational viscometer. A value of the shear thinning index of unity indicates that the material is Newtonian in behavior. A value greater than unity indicates shear thinning behavior.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 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.