Specifications: The measured thickness 20mm, the speed of sound measurement accuracy of ± 5%Power: 3 * 1.5V, AA alkaline batteries (not included)Relative humidity: <90% RHStorage temperature: - 10 ~ 50 ℃Workpiece temperature: <60℃Operating current: <100mAWeight: 784g Package Included: 1 x Ultrasonic Thickness Meter (batteries not included)1 x Probe1 x User Manual1 x Carry Case Features: 100% brand new and high quality.This is a type of smart ultrasonic thickness meter and can measure thickness.It can measure sound speed of many type of materials, such as metal,plastic,ceramic,glass and other good conductors of ultrasonic wave.This ultrasonic thickness meter features high accuracy and high stability.The measuring range is 2-300mm, and sample to operate. Probe operating frequency: 2MHz Probe operating frequency: 2MHz Range: 2-300mm (steel) Resolution: 0.1mm Measurement accuracy: ± (l% H + 0.1) mm, H is the thickness of the object Pipe measurement lower limit: Dia. 20x3mm Sound speed adjustment range: 1000 ~ 9999m/s Known thickness of the measured speed of sound: measuring range of 1000 ~ 9999m/s Key Description: Prompt: If a measurement is carried out, another button operation except the power button is invalid. 1. On/off: Press the "Power on/off key" button to turn on the device. The backlight is automatically switched on. Press and hold the "" button for three seconds to turn off the device. 2. Calibration process: The device is properly calibrated before delivery. Users can re-calibrate if necessary. After turning on, press the "Cal" button to enter the calibration interface. Apply the ultrasonic coupling agent to the calibration block of the instrument and place the probe in the middle of the standard block. Record the probe after the measurement value is stable, and press the "VEL / Enter" button to complete the calibration. 3. Selection and adjustment of sound speed: The sound speed of the objects to be measured should be selected before measuring the thickness. Press the "VEL / Enter" button to display the sound speed. Press the "Plus button" or "Shift button" button to select the sound speed value of the material. If the sound speed value needs to be changed, press the "VEL / Enter" button to enter the sound speed setting status, and press the "Plus button" button or "Shift button" button to set the desired value. 4. Memory of the thickness value: Press the "memory" button and the display will start flashing. Press the "Plus button" or "Switch button" button to select the storage unit (1-10). After selection, press the "memory" button again. The thickness value at the following measurement is automatically stored in the unit. Each new value overwrites the previous one. 5. Thickness measurement: The material thickness can be measured using the well-known sound speed of the material. Before measuring, select the sound speed and apply bonding agent to the areas to be measured. Touch the probe lightly and press against the points to be measured. At the moment the screen is displayed. Clutch indicator "clutch indicator". If the icon flashes or is not displayed, it indicates faulty pairing. When removing the probe, the indicator disappears. 6. Measurement of sound speed: The sound speed can be measured using the material speed. Measure the material thickness accurately with a caliper or a micrometre. Apply bonding agent to the areas of the material to be measured and pair the probe with materials. Remove the probe after the measurement value has stabilized.Press the "Shift" button to select the number to be set, and press the "Plus" button to increase the number by 1 (switch between 0 and 9). Then set the displayed values to the known material thickness. Press the "VEL / Enter" button at the moment. The sound speed displayed on the screen is the sound speed of the material. At the same time, the sound speed is automatically stored in the current storage unit. 7. Check the stored thickness value: Press the "Memory" button and the "M" indicator will start flashing. Currently press the "Plus" button or "Shift" button to check the thickness value from unit 1 to unit 10. Press the "Memory" button again to retrieve the current image of thickness readings. Measurement Error Factor: 1. Super thin materials: If the thickness of the material to be measured is close to the lower limit of the probe, sometimes the phenomenon of double fraction may occur. The measurement result is twice the actual material thickness. Another type of phenomenon that causes an error is referred to as "pulse envelope curve and circulation". This makes the measurement result larger than the actual thickness. To obtain reliable readings, measurements and checks for measuring critical materials should be carried out. 2. Rusty materials: The material with rust on the surface and irregular materials can result in repeated measurement changes, even if there are no readings at the time of measurement. 3. Selection and use of bonding agents: Bonding agents are the substances that transmit ultrasonic energy. Improper selection and use of bonding agents increases measurement errors or causes no measurement to be carried out. Before measuring, use a suitable amount of bonding agent to apply evenly to the points of the objects to be measured. If the measuring temperature is too high, it is placed at the bottom of the probe.When measuring materials with a smooth surface, it is convenient to select low viscosity bonding agents. High viscosity bonding agents should be selected for materials with rough surfaces. 4. Errors in selecting sound speed: A failure to match the selected sound speed with the measured materials results in an incorrect measurement result. For abnormal measurements, pay attention to the correct selection of sound speed and adjust the sound speed value if necessary. 5. Wear of the probe: The probe surface is made of acrylic resin. Long-term use can increase coarseness and reduce sensitivity. Users can use 500# sandpaper to polish the probe surface or replace with a new probe. 6. Materials with non-parallel surfaces: If the top and bottom surfaces of the measured materials are not two parallel surfaces, it is impossible to get a correct measurement result or display readings. 7. Temperature influence: The temperature may have a certain influence on the transmission speed of the ultrasonic wave to affect the measurement result of the thickness. The sound speed can be adjusted again to remove the effect. Care and maintenance: 1. How to clean the case: Wipe the body of the instrument with a dry cloth at the time of cleaning. Do not use a wet cloth or corrosive cleaning agents. 2. Probe protection: When measuring on the surface of coarse material, do not push the probe with excessive force to avoid damage to the probe. Do not use the probe to measure objects with a surface temperature above 60 °C. After each use, the bonding agent and dirt on the probe should be removed. 3. Calibration Block Cleaning: Please completely clean the probe from bonding agents and dirt after use. If it is not used for a long time, some rust protection oil can be applied to it. Rust protection oil should be completely removed for next use. 4. Replace the battery: The battery should be replaced in time when the battery level is low. Pay attention to the polarity when inserting new batteries. Do not install in reverse order. If the product is not used for a long time, remove the battery to avoid corrosion on the battery box and terminal shoe due to battery leakage. 5. Do not store the product in humid environments.