HG/T 2450-1999 "Determination of apparent hardness of rubber rollers - Rubber International Hardness gauge Law" stipulates the test conditions, instruments and test procedures for the determination of apparent hardness of rubber rollers using the Rubber International Hardness gauge (IRHD). Hardness of rubber rollers is crucial to their use function and is affected by the rubber compound, roller diameter, coating rubber thickness and roller core characteristics. This standard specifies the Measuring method, expressed in the Rubber International Hardness (IRHD) value, which is suitable for all types of rubber rollers. The standard requires that the parking time of samples made or finely ground is not less than 16 hours, and the parking time for determinations as arbitration is not less than 72 hours.