Method of Bitumen Penetration Test
The penetration value of bitumen is the vertical penetrated measure of the standard needle into the bituminous material under specific weight and temperature.
This distance is measured in one-tenth of a millimeter. A penetration test of bitumen is used to evaluate the consistency of bitumen.
Standard Test Methods
AASHTO T 49, ASTM D 5 and EN1426: Penetration of Bituminous Materials.