5.1 This method is based on the penetration of a specific type of indentor when forced into the material under specified conditions. The indentation hardness is inversely related to the penetration and is dependent on the elastic modulus, viscoelastic behavior of the material, geometry of the indentor, the applied force and temperature at test. This test method is empirical and therefore primarily for control purposes. No simple relationship exists between indentation hardness determined by this test method and any fundamental property of the material tested.

1.1 This test method covers Type A Durometer hardness of road marking thermoplastic material at elevated temperatures.

1.2 This test method is similar to Test Method D2240 for hardness with special attention given to keeping the temperature of the test sample and instrument constant. Within the highway materials community, it is sometimes known as “indentation resistance.”

1.3 All materials, instruments or equipment used for the determination of temperature, hardness and time shall be traceable to National Institute of Standards and Technology or other internationally recognized organizations parallel in nature.

1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.

1.5 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.