The electro-hydraulic servo fatigue testing machine, as a high-precision and high reliability testing equipment, is widely used in fields such as materials science and mechanical engineering to evaluate the fatigue performance of materials or components under cyclic loading. Regular calibration of the loading accuracy of the electro-hydraulic servo fatigue testing machine is essential to ensure the accuracy and reliability of the test results. This article will provide a detailed introduction to the steps and precautions for calibrating the loading accuracy of an electro-hydraulic servo fatigue testing machine.
1、 Preparation before calibration
Equipment inspection: Ensure that all components of the testing machine are intact and undamaged, especially the hydraulic system, servo control system, and data acquisition system. The normal operation of these systems is the foundation for ensuring loading accuracy.
Environmental conditions: Calibration should be carried out under stable environmental conditions to avoid the influence of external factors such as temperature and humidity on the calibration results. Generally speaking, the ambient temperature should be controlled at 20 ± 5 ℃, and the relative humidity should not exceed 80%.
Tool preparation: Prepare the standard instruments required for calibration, such as standard weights, force sensors, etc. These standard instruments should be verified by institutions to ensure their accuracy.
2、 Calibration steps
Turn on the equipment: According to the operating procedures of the testing machine, first turn on the hydraulic source, and then turn on the control system and cooling system. During the startup process, pay attention to observing the operation of each system to ensure that there are no abnormalities.
Force sensor calibration: Place the standard weight on the loading platform of the testing machine, read the output value of the force sensor through the control system, and compare it with the actual weight of the standard weight. If the deviation exceeds the allowable range (usually ± 0.5% FS), the force sensor needs to be adjusted or replaced.
Displacement sensor calibration: Use a micrometer or other high-precision measuring tool to measure the actual displacement of the loading platform of the testing machine, and compare it with the displayed value of the control system. If the deviation exceeds the allowable range (usually ± 0.5% FS), the displacement sensor needs to be adjusted or replaced.
Loading system calibration: After the calibration of the force sensor and displacement sensor is completed, perform overall calibration of the loading system. By setting different loading forces or displacement values through the control system, observe whether the actual output of the testing machine is consistent with the set values. If the deviation exceeds the allowable range, further adjustments and optimizations need to be made to the loading system.
Record and report: During the calibration process, detailed records of each step's operation and measurement results should be kept. After calibration is completed, a calibration report should be prepared, including the calibration date, calibration personnel, calibration results, and recommendations.
3、 Precautions
Safe operation: During the calibration process, the operating procedures and safety regulations of the testing machine should be strictly followed to ensure the safety of personnel and equipment.
Selection of standard instruments: The selected standard instruments should have sufficient accuracy and stability to ensure the accuracy of calibration results.
Calibration cycle: Develop a reasonable calibration cycle based on the frequency of use and working environment of the testing machine. Generally speaking, it is recommended to conduct a comprehensive calibration at least once a year.
Maintenance and upkeep: Regularly maintain and upkeep the testing machine, such as replacing hydraulic oil, cleaning filter screens, etc., to ensure its long-term stable operation and maintenance of loading accuracy.
Professional operation: Calibration work should be carried out by personnel with professional knowledge and experience to ensure the standardization of the calibration process and the accuracy of the results.
The loading accuracy of the electro-hydraulic servo fatigue testing machine is one of the key factors affecting the accuracy and reliability of the test results. Through regular calibration and careful maintenance, the loading accuracy of the testing machine can be ensured to remain at a high level, providing strong support for research in fields such as materials science and mechanical engineering. At the same time, attention should also be paid to strictly following the operating procedures and safety regulations during the calibration process to ensure the safety of personnel and equipment.