In 2013, many Vickers hardness testers were gradually upgraded or replaced with newer models. Previously, we covered some common technical knowledge about Rockwell hardness testers. Today, Fangfang Xiaobian is here to provide you with the latest and most up-to-date technical information on Vickers hardness testers for your reference. First, the zero adjustment of a Vickers hardness tester: this device features a memory function that allows it to automatically reset the zero position when power is turned on. However, if the operator changes, the zero must be reset again to ensure accurate results. To adjust the zero, rotate the left and right wheel hubs so that the inner edges of the two lines are as close as possible, minimizing the light gap between them until they reach a critical point without any visible gap. Then press the CLR key to set the zero point. Second, the requirements for the diamond cone head of a Vickers hardness tester: 1. The angle between the two opposite faces of the diamond cone should be 136° ± 30'. 2. The top edge of the diamond pyramid indenter must not exceed 2 microns. 3. Within 0.3 mm from the top of the indenter, there should be no defects such as cracks, blisters, chipping, or scratches when viewed under 50x magnification. The surface finish should not be lower than 12. 4. The axis of the diamond cone must align with the stem of the pressure head, with a deviation not exceeding 0.03 mm and a skew not more than 30'. Third, general requirements for using a Vickers hardness tester: 1. The test surface of the sample must be smooth, free of oxides and foreign contaminants. The surface roughness (Ra) should generally not exceed 0.2 microns to ensure accurate measurement of the indentation diagonal. 2. During sample preparation, avoid the effects of cold or hot processing on the surface. 3. The thickness of the sample or test layer should be at least 1.5 times the average diagonal length of the indentation. Select an appropriate test force accordingly. Fourth, correct measurement procedure: Use the micrometer eyepiece to observe the rotating left line positioning wheel, and move the left line so that it just touches the left corner of the indentation diagonal. Rotate the measuring wheel vertically until the right moving line is tangent to the right corner. Press the micro-input button on the right side of the diagonal, and the LCD will display D1. Wait for D2 to be input. Move the micrometer to measure the distance between the observation line and the indentation corner, then reposition the left line to be perpendicular to the diagonal. Rotate the measuring wheel so that the lower moving line touches the bottom right corner of the indentation. Press the input button, and the data will be entered into the tester to display the hardness value. If needed, repeat the process for further tests. Fifth, the difference between a Vickers hardness tester and a micro Vickers hardness tester: A standard Vickers hardness tester measures materials with test forces ≥ 49.03 N (or HV5). A small load Vickers hardness tester operates with forces between 1.961 N and 49.03 N (or HV0.2 to HV5). A micro Vickers hardness tester uses forces between 0.09807 N and 1.96 N (or HV0.01 to HV0.2). These instruments are used for different levels of hardness testing, with micro Vickers being ideal for thin layers or small samples. Sixth, working precautions: Do not move the test piece while the motor is running. Wait until the unloading process is complete before moving the sample, as doing so can damage the instrument. Seventh, testing irregular workpieces: When testing irregularly shaped samples, be cautious to avoid the indenter hitting the sample, which could damage the press head. Eighth, calibration before use: Calibration is typically done using a standard block. If the measured value differs slightly from the standard block’s value, it is usually within acceptable error limits. The official certificate for the Vickers hardness tester is issued by metrology authorities. If necessary, you can also calibrate the machine using your own standard blocks. Ninth, checking the perpendicularity between the spindle and the work surface: Mount the test rod firmly on the main shaft and check it with a square and feeler gauge in two perpendicular directions. Remove and reinstall the rod, then measure again. The maximum deviation should not exceed the specified limit. Tenth, adjusting the lifting shaft elasticity: Adjust the screws at both ends of the lifting shaft sleeve, turn the handwheel to allow the lifting shaft to move freely up and down without sticking, ensuring proper lifting and loosening functionality. By following these guidelines, users can ensure accurate and reliable measurements while maintaining the longevity of their Vickers hardness testing equipment.
Led Running Light,Led Running Bulb String Lights,Decoration Running Bulb String Lights,Waterproof Running Bulb String Lights
Tianjin Jinji Optoelectronic Technology Co., Ltd. , https://www.tjjjgd.com