Ball Pressure Apparatus - IEC For Electrical Lab Training

Ball Pressure Apparatus - IEC - For Electrical Lab Training External parts of thermoplastic insulating materials, deterioration of which might cause the electrical appliance to become unsafe, shall be sufficiently resistant to deformation at elevated temperatures. Compliance is checked by subjecting plastic parts made of insulating materials to the ball pressure test.   In this test the test specimen is placed over a rigid metallic stand with its upper face lying in a horizontal plane. A spherical indentor of 5 mm diameter is pressed against it under a force of 20 N. The assembly is maintained at a specified temperature for a period of one hour. At the end of this time period the diameter of impression produced by the ball on the surface of the material is measured with the help of a traveling microscope. This diameter shall not be greater than 2.0 mm for the material under test to be considered acceptable in this test.   The  Ball Pressure Apparatus consists of a hardened and ground carbon steel ball held in a suitable adopter. The adopter carries a stirrup arrangement to apply the specified load on the test specimen placed on a flat surface.   A metallic stand having a flat horizontal platform for placing the test specimen on is also supplied with the equipment.