Load is applied by a hydrostatically lubricated ram. Main cylinder pressure is transmitted to the cylinder of the pendulum dynamometer system housed in the control panel. The cylinder of the dynamometer is also of self - lubricating design. The load transmitted to the cylinder of the dynamometer is transferred through a lever system to the pendulum. Displacement of the pendulum actuates the rack and pinion mechanism which operates the load indicator pointer and the autographic recorder. The deflection of the pendulum represent the absolute load applied on the test specimen. Return movement of the pendulum is effectively damped to absorb energy in the event of sudden breakage of the specimen.
Machine consists of Straining Unit
This consists of a hydraulic cylinder motor with chain sprocket drive and a table coupled with the ram of the hydraulic cylinder. mounted on to a robust base. The cylinder and the ram are individually lapped to eliminate friction. The upper cross-head is rigidly fixed to the table by two straight columns.
The lower cross-head is connected to two screwed columns which are driven by a motor. Axial loading of the ram is ensured by relieving the cylinder and ram of any possible side loading by the provision of ball setting. An displacement elongation scale, with a minimum graduation of 1 mm. is provided to measure the deformation of the specimen.
Tension test is conducted by gripping the test specimen between the upper and lower cross heads. Compression. transverse, bending. shear and hardness tests are conducted between the lower crosshead and the table.
The lower cross-head can be raised or lowered rapidly by operating the screwed columns, thus facilitating ease of fixing of the test specimen.
Control Panel :
The control panel consists of a power pack complete with drive motor and al1 oil tank, control valves, a pendulum dynamometer. a load indicator system and an autographic recorder.
The power pack generates the 2 maximum pressure of 200 kgf/cm . The hydraulic pump provides continuously non- pulsating oil flow. Hence the load application is very smooth.
Hand operated wheels are used to control the flow to and from the hydraulic cylinder. The regulation of oil flow is infinitely variable. Incorporated in hydraulic system is a regulating valve, which maintains a practically constant rate of piston movement. Control by this valve allows extensometer readings to be taken.