The universal material testing machine adopts the microcomputer control full digital broadband electro-hydraulic servo valve to drive the precision hydraulic cylinder. The microcomputer control system can automatically control the test force, displacement and deformation in a variety of modes to complete the tensile, compression and bending tests of the samples. It meets the requirements of the national standard GB / T228-2002 tensile test method for metallic materials at room temperature and other standards. This is the introduction of universal material testing machine maintenance precautions and purchase skills

1、 Precautions for maintenance of universal material testing machine

1. Universal material testing machine as a high-tech testing equipment, we can find that it has a different structure. In the process of quarterly maintenance, the relevant staff need to carry out the corresponding inspection for each structure of the equipment to ensure that the lubrication parts have done enough lubrication measures.

2. We need to thoroughly check the main part of the testing machine to ensure that there will be no abnormal noise during use. In addition, there are different buttons and control keys in the universal testing machine, which must be checked in the quarterly maintenance plan to see if they can be flexibly controlled.

3. At this stage, different manufacturers will be equipped with the corresponding protection device and equipment control device system, we need to check these two key points to ensure that the overall performance of the equipment is better protected.

4. Universal material testing machine some dead space also need to be maintained, and to check the relevant performance of the equipment, test whether the test can be done.

5. Always check the cables and wires of the equipment to see if they are aging or damaged. Once found, they must be replaced in time.

6. Universal material testing machine has many different fixed screws, pay attention to each part of the screw nut is loose, rust and other problems, found that any parts of the testing machine have problems, need to be replaced in time.

7. It is necessary to check the circuit of universal testing machine to ensure that it has a good grounding state and there are no missing or damaged components. Once any missing or damaged components are found, the components of the original manufacturer must be ordered for replacement, so as to avoid the distortion caused by the influence of later detection test data.

2、 Purchasing skills of universal material testing machine

1. Range selection of universal material testing machine:

According to the load of the test material, the required load of the testing machine (i.e. range) is selected. It is recommended that the material test load should be about 50% - 80% of the range of the testing machine, which can not only ensure the resolution of the test, but also prolong the service life of the testing machine.

2. Precision grade selection of universal material testing machine:

At present, the accuracy of domestic testing machines generally use level 1 and level 0.5. For general material test, level 1 testing machine is enough, so it is unnecessary to spend more money to improve the accuracy. For scientific research and material analysis, level 0.5 testing machine is needed; In fact, there is no obvious technical difference between level 0.5 and level 1 precision testing machines. The calibration methods and means are basically the same, which is the difference of correction points. With the development of sensor technology, the linearity of sensor elements has reached a very high level. If the measuring circuit has no defects and the anti-interference performance is good, all testing machines will reach level 0.5 Accuracy is no problem, for electrical measurement has far exceeded the limit of 0.5 level, the relative error of national standard definition needs to be discussed.

3. Selection of resolution and dynamic performance (bandwidth) of universal material testing machine:

Resolution is an important parameter of the testing machine, the appropriate resolution will be conducive to the resolution of the measurement, measuring a small division, effective resolution and dynamic performance is a pair of contradictions, blindly improve the effective resolution is at the expense of dynamic performance (bandwidth), the reduction of bandwidth directly leads to the material yield fluctuation is not obvious, even yield is a flat Therefore, this pair of parameters should also be considered effectively in the selection.

4. Synchronous performance selection of universal material testing machine:

The data collected in material test is the load and deformation of the material at the same time. If the two are not synchronized, the load will appear forward to the deformation or the deformation will appear forward to the load. For the problem that the same load corresponds to two deformations when measuring elastic material in the forward and backward travel, the forward and backward travel curves do not coincide.