Polydynamometer

A polydynamometer is a technical device that can be used to measure traction force and tension at the terminals of an electric motor. Polydynamometers are used in the field of electrical power engineering, when diagnosing generators in operation, and are also used for testing internal combustion engines, pumps, and many elements in which the movement and attraction of a power load occurs. The device structurally consists of two frames with different friction force values. This allows the use of a different range of measured loads on their terminals. An important advantage is the ability to account for differences between thrusts. The device can be assembled and adjusted by itself: sometimes two walls need to be expanded, while the third needs to be removed. Then the differential pressure gauge readings will be distorted. Another important advantage of the differential device is its light and simple assembly.

The device consists of a frame with threaded holes and three pins called sliders. This device serves as a fulcrum for a moving rod, which has a support at one end. On the other side of it there is a dynamometer device, calibrated in kg. The models used can measure values ​​of 20-300 kg, and the accuracy of the device is up to 1%. The device is supplied in a special box that allows it to be transported. An indicator mounted on the clamp informs the user about the current loads.

The principle of operation of a polydynamometer is that the dynamometer system has two zeros without a click. The mechanical roller can rotate freely along with the shaft, held only by the scrolling resistance. To start measuring, the user must pull on the shaft. The clamp displays the current load it can withstand. When the traction force reaches a certain value, the pendulum takes the form of a weight and the load is recorded using an indicator. At this moment the reading jumps. However, the device does not always stop at this stage. The system can fail if there are a large number of rubber inserts, which are a support that creates false static voltage. Dynamometers that use friction force allow one to achieve significantly greater accuracy and sensitivity when exposed to a small (compared to a pneumodynamometer) load.