The universal material testing machine is also called the tensile machine, and its precision is very important. It affects the accuracy and correctness of the results when we test. However, there are always some factors that affect the testing accuracy of the tensile machine. Today, Xiaobian Let's talk about the factors that affect the accuracy of the rally.
1. The force value sensor of the tensile machine must know that the accuracy and stability of a test machine are determined by the quality of the sensor. The current value of the sensor used in the tensile machine on the market generally uses spoke sensors. The small force value generally uses S-type sensor. The inside of the sensor is generally resistance strain gauge. If the accuracy of the strain gauge is not high or the rubber used for fixing the strain gauge is not good in aging resistance or the material of the sensor is not good, the sensor will be affected. Accuracy and service life.
2. The ball screw of the component that drives the movement of the sensor. If the screw has a gap, the test data made in the future will directly respond to the maximum deformation and elongation after the test. At present, some of the screw rods on the market use T-shaped ordinary screw rods, so that the gap is relatively large, and the second is that the friction force is relatively large and the service life is short.
3. The transmission system of the tension machine. At present, some of the tension machine transmission systems on the market use reducers, and some use ordinary belts. The main drawbacks of these two transmission methods are: the former requires regular lubrication, and the latter cannot be guaranteed. The synchronism of the drive affects the test results.
4, the power source (motor) of the tension machine is also called motor. At present, some tensile machines on the market use ordinary three-phase motor or variable frequency motor. This kind of motor adopts analog signal control, the control response is slow, the positioning is not accurate, and the general speed regulation range Narrow, high speed, no low speed or low speed, no high speed, and speed control is not accurate.
5, universal testing machine tensile machine measurement and control system (that is, software and hardware), the majority of the current rally machine measurement and control system on the market is 8-bit microcontroller control, low sampling rate, and poor anti-interference ability, the other is AD The converter if the number of bits in the AD converter is also low resolution. Then the measurement will not be accurate.