Suitable for Charpy & Izod Impact tests on various materials. Works on Pendulum principle
Working of Impact Testing Machine:
The Pendulum is mounted on antifriction bearings. It has two starting positions, the upper one for Charpy and the lower one for Izod testing. On release, the pendulum swings down to break the specimen and the energy absorbed in doing so is measured as the difference between the height of drop before rupture & height of raise after rupture of the test specimen; the measurement is read from the maximum pointer on the dial scale.
Control of Pendulum:
The Pendulum is supported in the starting position is by a self resetting latch. The release mechanism is operated by lever. The pendulum release latch moves only when this lever is operated.
Strikers & Supports
There are two strikers & one combined support available for fitting into the pendulum & on to the base of the machine for Izod, or Charpy test. Changing from one striker to another is achieved simply by fixing the new striker into its position.
The sample to be tested is kept on support anvils that are typically made from Alloy Steel. These anvils are fitted on the base of the machine. There is also an end stopper that holds the sample in a central position between the support anvils.
The Izod test piece is clamped vertically in Izod support anvils, fitted at the foot of the machine. The support is provided with a machined vertical groove to suit the test piece size. The front clamp piece & allen screw enable clamping of the test piece at correct height with the help of Izod setting gauge.
The highly strained & wearing parts like support blocks & strikers are of special alloy steels duly heat treated. Safety guard for the user is provided.
Initial potential energy for Charpy is 300 Joules & for Izod is 170 Joules with a Least Count of 2 Joules (for Analogue models) & resolution of 0.5 Joules (for Digital Model).
Related Standards: IS:3766-2003, IS:1598-1977, IS:1757-1999, IS:1499-2003, BS:131-Part-I,II,III,IV & BS EN-10045-1993 (for Charpy).