After the test rod is automatically wound, it can accurately stop on the zero position of the dial.
When the rebound degree stops counting, the dial stops rotating, so that the LED display and the dial reading are consistent;
When the instrument is used, it is not necessary to adjust the sensor for various specifications of samples;
The coil should be slowly loosened during rebound, without sudden rebound or sudden beating phenomenon;

Using single chip microcomputer control, simple operation, high sensitivity, good repeatability;