ISO 48:2010 pdf download – Rubber, vulcanized or thermoplastic — Determination of hardness (hardness between 10 IRHD and 100 IRHD).
6.3 Methods CN, CH, CL and CM The test piece shall be either a complete article or a piece cut therefrom. The underside of a cut piece shall be such that it can be properly supported during the hardness test. If the surface on which the test is to be made is cloth-marked, it shall be buffed prior to testing. Test pieces shall be allowed to recover at a standard laboratory temperature (see ISO 23529) for at least 16 h after buffing and shall be conditioned in accordance with Clause 8. The conditioning period may form part of the recovery period. 7 Time interval between vulcanization and testing Unless otherwise specified for technical reasons, the following requirements shall be observed (see ISO 23529): ⎯ For all normal test purposes, the minimum time between vulcanization and testing shall be 16 h. In cases of arbitration, the minimum time shall be 72 h. ⎯ For non-product tests, the maximum time between vulcanization and testing shall be 4 weeks and, for evaluations intended to be comparable, the tests, as far as possible, shall be carried out after the same time interval. ⎯ For product tests, whenever possible, the time between vulcanization and testing shall not exceed 3 months. In other cases, tests shall be made within 2 months of the date of receipt by the purchaser of the product. 8 Conditioning of test pieces 8.1 When a test is made at a standard laboratory temperature (see ISO 23529), the test pieces shall be maintained at the conditions of test for at least 3 h immediately before testing. 8.2 When tests are made at higher or lower temperatures, the test pieces shall be maintained at the conditions of test for a period of time sufficient to reach temperature equilibrium with the testing environment, or for the period of time required by the specification covering the material or product being tested, and then immediately tested.