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This impact tester uses the force of two pendulums that fall through each other and break a sample oriented in the Charpy manner. The resistance to breakage corresponds to a reading on the analog force scale. This unit also has a precision potentiometer mounted on the main shaft that sends a signal to a digital readout that can display the force reading in either ft-lbs or Pascals. Analog Ft-Lb scale and rotary union (brass unit at bottom of pic) The pendulums are released using an air cylinder that is actuated by simultaneously pressing both release buttons on either side of the control box. Because of the large amounts of inertia of these heavy swinging pendulums a hydraulic disc brake stops the swinging between the two pendulums. The brake is actuated with a hand pumped master cylinder. With the brake being located on one of the pendulums, a rotary union is used. When we pump the master cylinder a little oil leaks out of the union, it needs to be replaced. The sample is mounted with spring loaded clips. Included are two new extra sets of these clips. The sample mounting area has these dimensions: 9"L x 2"W x 5/8" H. The actual size of the specimen is determined by ASTM-E604. The striker on the other pendulum is rounded and replaceable. An extra new one of these is also included. The radius of the pendulum between the shaft and the striking area is about 23". Overall dimensions of whole machine are 68"L x 40W x 67H. Machine Condition: Overall mechanical and structural condition of machine is very good. We plugged in the control panel and the digital display turned on. Once you press the reset button the display shows a number that changes when you turn the potentiometer (the pot turns on the shaft for calibrating purposes, then you lock it down). The shaft on this pot is bent where it goes into the main shaft. It does not affect the operation of the pot itself, but it would affect the operation when the pendulums drop. There is also strain gauge implanted in the striker pictured above. This sensor does not plug anywhere into the control box and is not needed to perform tear testing. Besides the striker sensor there is also another sensor on the arm of one pendulums and the trigger for it is on the other pendulum. This sensor uses a fiber optic gap that broken by a dark plate on the opposing pendulum. The fiber-optic wires go into some sort of light source/transducer that has a two wire canon connector coming out of it that goes to another piece of instrumentation that is not included. This sensor also is not needed for tear testing. In summary, there is no reason why this machine can not be used with the current setup if the potentiometer shaft is straightened or replaced and the unit is calibrated. But, if one wanted they could install an updated transducer and display unit which would make this impact tester a very capable and valuable machine. Call with any questions. Front overall pic (Safety guards on other side included but not installed) (Air cylinder shaft at top of picture pulls square slider block up which releases the two vertical levers. When the levers rotate the catch on the bottom of the lever releases the pendulums) There is a second release button on the opposite side of control box that needs to be depressed at the same time as this one. The bottom left receptacle is labeled "HOIST". There are no controls to operate a hoist on the control box, so it must alway be energized. Keep in mind the pendulums are heavy and you would need a hoist to lift them every time. Extra Striker and Specimen holding clips Call with any questions. |