Standard tension of test machine

The jaws equipped with the machine should be coated with anti-rust oil for storage; since the jaws of the impact test machine are often used, they are prone to wear. When there is too much oxide scale, it is easy to cause damage to small pistons and oil leakage, so the jaws should be cleaned frequently and kept clean (cleaned after each test); the sliding surfaces of the inlay plate and the dovetail grooves on the lining plate should be kept clean, and a thin layer of MoS2 (molybdenum disulfide) grease should be applied regularly; regularly check the screws in the jaws, if they are loose, tighten them in time; regularly check the transmission status of the sprocket, if they are loose, please re-tension the tensioner. When the pointer of the impact tester swings slightly, the stretching immediately stops, that is, the standard tensile sample is in a tensile state. At this time, an extensometer or a strain gauge is installed on the standard tensile sample. The impact tester continues to stretch the standard tensile sample according to the speed specified in GB/T228-2002 standard. The extensometer or strain gauge displays the elongation of the standard tensile sample. According to Hooke's law, the elongation is converted into the tensile value, and then compared with the same force value point as the standard sample on the impact tester dial. The technical status and accuracy of the tester are determined based on the difference in the comparison value. The test speed and height of the test machine should be selected based on the performance of the product to be measured, and the test speed of the test machine should be roughly determined (a test model that can be purchased that can set the speed).

Understand the test space required for the test. The beam displacement and vertical test space required for the test (generally, the beam displacement is 898mm, and the vertical test space is 1067mm). If it is an elastomer test, the beam displacement and vertical test space will be higher. The specific situation needs to be determined according to the experimental requirements. According to the force value of the impact tester in the range to be tested, the standard tensile sample is selected. The force value of the standard tensile sample is between 60% and 90% of the full-scale force value of the range. The standard tensile sample is clamped on the impact tester and the impact tester is allowed to stretch the standard tensile sample according to the speed specified in the GB/T228-2002 standard.