1、 Preparation before operation

（1） Equipment and accessory inspection

(1) Confirm that the appearance of the AG-500 ultrasonic thickness gauge host is not damaged, the button response is normal, and the display screen has no abnormal display.

(2) Based on the characteristics of the tested material, thickness range, and measurement environment, select an appropriate probe (such as a micro diameter probe for thin-walled measurements and a high-temperature probe for high-temperature environments), and check that the probe cable is not damaged and the connection is firm.

(3) Prepare qualified coupling agents (high-temperature coupling agents should be selected for high-temperature environments) and standard test blocks (equipped with 4mm test blocks or customized calibration test blocks) to ensure that the coupling agents do not deteriorate and the surface of the test blocks is not worn.

(4) Install two No. 5 alkaline batteries, check the remaining battery level indicator after turning on, ensure that the battery is fully charged, and avoid interruption of operation due to insufficient battery during the measurement process.

（2） Environment and Test Item Preparation

(1) Confirm that the measurement environment temperature is between -20 ℃ and 50 ℃, and avoid measuring in environments with strong vibration and electromagnetic interference.

(2) Clean the measuring surface of the tested object of impurities such as oil stains, rust, coatings, etc., to ensure that the surface is smooth, dry, and free of obstacles that affect the propagation of ultrasonic waves.

2、 Instrument setup and calibration

（1） Basic parameter settings

(1) After booting up, enter the settings interface through the menu key and select the language (Chinese/English) and unit system (metric mm/imperial inch) according to your needs.

(2) Refer to the material sound velocity table and input the corresponding sound velocity values for the tested material (such as 5920m/s for ordinary steel and 6340-6400m/s for aluminum); If the speed of sound is unknown, the speed of sound can be measured using a known thickness test block in the future.

(3) Choose the appropriate measurement function. For routine measurements, the default mode can be used. If multiple measurements are required and the average value is taken, the average measurement function can be activated. If it is necessary to determine whether the measurement exceeds the tolerance, a limit measurement can be set.

（2） Instrument calibration

(1) Automatic calibration: Clean the surface of the standard 4mm test block, apply coupling agent, attach the probe to the surface of the test block, press the calibration button to start automatic calibration, and wait for the buzzer to prompt calibration completion to complete the calibration.

(2) Custom calibration: If higher adaptability is required, single point calibration or dual point calibration can be selected. Attach the probes to the corresponding thickness standard test blocks, input the thickness values of the test blocks in sequence, and follow the prompts to complete the calibration process. After successful calibration, the instrument will save the calibration parameters.

3、 On site measurement operation

(1) Apply a thin layer of coupling agent evenly on the cleaned measurement area of the test piece, ensuring that the coupling agent covers the measurement point without any residual bubbles.

(2) Hold the probe and vertically attach the bottom surface of the probe to the measurement point where the coupling agent is applied. Gently press the probe to ensure coupling with the surface of the measured object. The instrument will display a coupling status prompt. After confirming that the coupling is good, take the reading.

(3) Keep the probe stable and record the measurement results after the display screen value stabilizes; If multiple measurements are required, the probe can be moved to different measurement points to repeat the above operation, and the instrument's functions such as reading capture and difference measurement can be used to obtain the required data.

(4) If the sound speed needs to be adjusted during the measurement process, the dynamic sound speed measurement function can be used: input the size of the measured part with a known thickness, and dynamically scan the probe on the measured part. The instrument will automatically calculate and update the sound speed value, improving the accuracy of subsequent measurements.

(5) During the measurement process, if the buzzer emits an over limit prompt, it is necessary to check the measurement parameter settings, probe coupling status, or surface condition of the measured object, eliminate any abnormalities, and then re measure.

4、 Data storage and organization

(1) After each measurement is completed, if data needs to be saved, the measurement values, sound velocity values, and other parameters can be stored in the instrument by pressing the storage button. The instrument supports storing 40 sets of thickness measurement data and 40 sets of parameter datasets.

(2) After all measurement work is completed, the stored data can be viewed through the instrument menu for recording or exporting.

5、 Closing after operation

(1) Press and hold the shutdown button to turn off the instrument, avoiding automatic shutdown caused by idle equipment and power loss.

(2) Clean the residual coupling agent on the surface of the probe, wipe it clean with a clean soft cloth, and avoid the coupling agent solidifying and affecting the next use.

(3) Organize the host, probe, coupling agent, standard test block, battery and other accessories, and store them properly in the ABS instrument box to avoid moisture, pressure or damage to the equipment.

(4) Record the usage of instruments, including measurement objects, measurement time, calibration status, and equipment status, for easy maintenance and traceability in the future.