Deflection Tester

Deflection Tester

The 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 test

IS 867 - 1963 Methods of Test for Phenolic Moulding Materials
ISO 75 ? 1 ? 1993 Plastics - Determination of Temperature of Deflection under Load

Technical Details

• Dimensions of the test specimen 3 to 4.2 mm wide 9.8 to15 mm thick 120 ? 10 mm long
• Distance between supporting edges 100 ? 2 mm
• Radius of supporting and loading edges 3.0 ? 0.2 mm
• Temperature Up to 300?C (least count 1?C)
• Deflection measurement 0 - 10 mm (least count 0.01 mm)