How to calibrate the universal tensile test machine?

How to calibrate the universal tensile machine?
The tensile testing machine has been used for a long time, which will make the test of the universal tensile test machine inaccurate.
I. test speed calibration of tensile testing machine
When we calibrate the test speed of the testing machine
(1) First, write down the starting position of the machine beam;
(2) Then select the speed value on the control panel (measure the cross arm stroke with a standard straight steel ruler);
(3) When the machine is started, the electronic stopwatch starts to count for 1 minute. When the stopwatch reaches the time, press the machine stop key;
(4) According to the time of the stopwatch, record the cross arm travel value as the rate per minute (mm / min), observe the difference between the cross arm travel value and the straight steel ruler, and calculate the cross arm travel error value, which shall not exceed ± 1%.
Second, calibration of various force values of tensile testing machine
Open the operation interface of the tensile testing machine and click the calibration program. First, we take a standard weight and hang it lightly on the upper fixture connecting seat, click to start the test, then record the force value displayed by the computer and calculate the difference with the standard weight. The error should not exceed ± 1%. If there is a large error, there should be a problem with the sensor, Try to reset the force value of the software and conduct multiple tests.
Third, displacement calibration of tensile testing machine
This needs to reset the current displacement, and then open the correction interface, which displays the moving distance. This is actually an error. It should be reset, so that the tensile testing machine will be accurate in the next test.
In the process of using the universal tensile machine, pay attention to keep the testing equipment clean, and clean the site after the test; In case of any abnormality during equipment operation, immediately press the emergency stop button. Prevent more dangerous things from happening.