The JF 1208-2008 standard provides guidance on the calibrating of asphalt penetrators. The specification applies to manual and automatic asphalt penetrators. The penetration index is obtained by measuring the depth of indentation of asphalt samples by pressing them using standard needles at specified temperature conditions. The specification cites relevant standards and technical literature, including "Asphalt Penetration Determination Method" and "Road Oil Asphalt Penetration Tester", and describes in detail the instrument's calibrating procedure, measurement uncertainty assessment, and instrument characterization. The standard ensures the accuracy and conformity of asphalt penetrators, providing a reliable benchmark for testing the physical properties of asphalt.