This test method deals with the standards for the measurement of apparent viscosity of roofing bitumen by mean of a parallel plate plastometer. This method involves measuring viscosity using pre-determined arbitrary shear stress levels. The method involves molding the sample into a disc of specified dimensions, heating it to a selected temperature and placing it between the plates of a pre-heated apparatus and pressing under the standard conditions for a measured time.

1.1 This test method covers the measurement of apparent viscosity of roofing bitumen by means of a parallel plate plastometer. This test method is applicable for a viscosity range from 10² to 10⁹ Pa·s (10³ to 10¹⁰ poises). See Note 1.

Note 1—This relatively simple test method of measuring viscosity uses pre-determined arbitrary shear stress levels. Since roofing bitumens are non-Newtonian, other viscosity test methods may give different results.

1.2 The values stated in SI units are regarded as standard. The inch-pound units given in parentheses are for information only.

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.