Deflection Tester

Deflection TesterThe heat deflection temperature of plastic materials is the temperature at which the material deflects by a specified amount under the action of a specified stress. It is determined by supporting a rectangular test specimen over two cylindrical edged blocks and pressing it at the center of the supported span through a cylindrical edged loading tip. The test specimen, along with the supports and the loading frame, is kept in a high temperature bath whose temperature is slowly raised. The temperature at which the test specimen deflects through a predetermined distance is the heat deflection temperature of the material under testIS 867 - 1963 Methods of Test for Phenolic Moulding MaterialsISO 75 ? 1 ? 1993 Plastics - Determination of Temperature of Deflection under LoadTechnical DetailsDimensions of the test specimen 3 to 4.2 mm wide 9.8 to15 mm thick 120 ? 10 mm longDistance between supporting edges 100 ? 2 mmRadius of supporting and loading edges 3.0 ? 0.2 mmTemperature Up to 300?C (least count 1?C)Deflection measurement 0 - 10 mm (least count 0.01 mm)