The calibration of electronic tensile testing machines is the core link to ensure their measurement accuracy, reliability, and compliance with industry standards, involving multidimensional technical operations and systematic management. The following provides a detailed description of calibration preparation, core steps, software debugging, and maintenance management:

　　1、 Preparation before calibration

·environmental controlIt needs to be conducted in a standard laboratory environment, with a temperature maintained at 20 ± 2 ℃ and a humidity of ≤ 65%, to avoid thermal drift or electrical short circuits. At the same time, it should be kept away from vibration sources (such as compressors) to reduce interference.

·Equipment preheatingPreheat the device for 30 minutes to stabilize the sensor and circuit.

·Cleaning and maintenanceClean fixtures, sensors, and transmission components to avoid oil stains or impurities affecting accuracy; Check the stability of the power supply (voltage fluctuation ≤ 5%) and grounding resistance (<4 Ω).

　　2、 Core calibration steps

·Force calibration

weightLoading methodLoad the standard weight step by step to 10%, 50%, and 100% of the sensor range, record the displayed value, and calculate the error (formula: error=(displayed value - standard value)/standard value x 100%). Adjust the gain or zero point compensation to make the error ≤± 1%.

　　Comparison method of force measuring instrumentsReplace the sensor with a high-precision force gauge to synchronously apply tension, compare the deviation between the two, and apply it to high demand scenarios with an error<0.5% (such as aerospace).

·Displacement calibration

　　static calibrationManually move the crossbeam to a specific position (such as 10mm, 50mm), measure the actual displacement with a dial gauge, and input the correction parameters into the control system.

　　Dynamic verificationStart the testing machine to stretch the specimen at a fixed speed, use a grating ruler to monitor displacement data in real time, adjust the encoder pulse number or transmission ratio to ensure consistency.

·Speed and acceleration calibration

　　speed calibrationSet different speed gears (such as 1mm/min, 100mm/min), measure the actual speed using a photoelectric tachometer, and adjust the PID parameters to ensure an error of ≤± 0.5%.

　　Acceleration calibrationRecord acceleration phase data through acceleration sensors to ensure smooth curves without sudden changes.

·Fixture and centering adjustment

Use a spirit level to adjust the verticality of the fixture (with an error of<0.1 °), and use a laser alignment instrument to check the axis offset of the sample (which should be<0.1mm) to prevent data deviation caused by eccentric loading.

　　3、 Software and System Calibration

·Zero point and range calibration

After unloading all loads, perform the "reset" operation to eliminate sensor zero drift; After loading the full-scale weight, input the actual value to correct the software parameters.

·Filtering and noise suppression

Adjust the signal acquisition frequency (e.g. 1000Hz) and enable the low-pass filter (cut-off frequency 50Hz) to reduce electromagnetic interference.

·Protocol and Unit Settings

Select the calibration protocol (such as ISO 7500-1, ASTM E4), configuration unit system (N/mm ² or MPa), and testing method (tension/compression) according to the requirements.

　　4、 Verification and Record Management

　　verification test

Use standard samples (such as annealed copper sheets) for tensile testing, compare the data differences before and after calibration, and confirm the adjustment effect.

　　documentation

Fill in the "Calibration Record Form" in detail, including environmental conditions, standard number, error value, and adjustment steps, and obtain a CNAS recognized calibration certificate from an authorized institution.

　　5、 Calibration cycle and precautions

　　Cycle suggestionUnder normal circumstances, calibration should be conducted at least once a year, and the frequency of calibration should be increased before high-frequency use or critical testing; Equipment should be recalibrated immediately after maintenance or collision.

　　exception handlingIf the error exceeds the standard, it is necessary to investigate issues such as sensor aging, amplifier failure, or mechanical wear. If necessary, contact the original factory or third-party metrology institution for maintenance.

　　Safety SpecificationsOverloading is strictly prohibited during the calibration process. After completion, unload the weights and disconnect the power supply in a timely manner to avoid sensor overload damage.