Automatic Shore hardness tester is an instrument used to measure the hardness of materials, especially for testing the hardness of materials such as rubber and plastic. Shore Hardness has different ranges, with Shore A hardness suitable for soft materials such as rubber, and Shore D hardness suitable for harder materials such as hard plastics.
Testing standard for automatic Shore hardness tester
Standardized testing methods
When testing with an automatic Shore hardness tester, the following standardized methods are usually followed:
Testing standards: Testing shall be conducted in accordance with international standards ISO868 "Shore Hardness Test Method for Plastic Hardness", ISO7619 "Shore Hardness Test Method for Rubber", and the American ASTM D2240 standard. Different materials and applications have different testing methods and hardness ranges.
Testing principle: The hardness tester applies a certain pressure to the surface of the test material through a steel needle or metal cone, and then determines the hardness value by measuring the displacement of the hardness tester pointer. For the Shore A hardness tester, the needle used is smaller and suitable for soft materials; For the Shore D hardness tester, a larger needle is used, which is suitable for hard materials.
Display of hardness value
The Shore hardness value is automatically calculated and displayed through the sensor of the instrument, usually expressed as an integer to indicate the hardness of the material. The higher the hardness value, the harder the material.
test method
Preparation work: During testing, it is necessary to ensure that the surface of the tested material is flat, clean, and free of any impurities to avoid affecting the test results. For softer materials, a stable base can be installed on the hardness tester test bench to avoid result errors caused by instrument instability.
Pressure application method: The hardness tester will automatically apply standard pressure and maintain it for a certain period of time (usually about 10 seconds), allowing the hardness tester tip to press into the surface of the material being tested, and then display the measured hardness value.
Testing environment: Factors such as temperature and humidity can affect the results of hardness testing. Ideally, testing should be conducted under specified environmental conditions. The general standard test temperature is 23 ℃ and the humidity is 50%.
Hardness tester calibration
Automatic Shore hardness testers require regular calibration to ensure the accuracy of test results. Usually, standard hardness blocks (calibration blocks) are used for calibration. The calibration process is usually completed through manual or automatic programs.
test accuracy
According to the testing standards, the accuracy of an automatic Shore hardness tester is generally required to be ± 1 point. To ensure accuracy, external interference, vibration, and improper operation during testing should be avoided.
Types of Shore Hardness:
There are different types of Shore hardness, mainly A and D:
Shore A hardness: suitable for soft rubber, elastic materials, and certain plastics, with a measured hardness range of approximately 0 to 100.
Shore D hardness: suitable for hard plastics, hard rubber, and other harder materials, with a measured hardness range of approximately 20 to 100.
The key steps of Shore hardness tester testing are:
Test preparation:
Install the hardness tester firmly and ensure that the testing surface is clean and flat.
Select the appropriate Shore hardness range (A or D) based on the tested material.
Apply pressure:
Start the automatic hardness tester, press the testing button, and the hardness tester will automatically apply the predetermined pressure and insert it into the testing surface.
Read result:
After the test is completed, the automatic Shore hardness tester will display the hardness value, usually as an integer, indicating the hardness of the material.
Repeated testing:
To ensure measurement accuracy, multiple tests are usually conducted on different locations of the same material, and the average value is calculated.
Notes:
Material surface condition: The material surface should not have any pollutants, such as oil stains, dust, etc., which can affect the measurement results of the hardness tester.
Test depth: It should be ensured that when the hardness tester applies pressure, the probe only makes effective contact on the surface. If the hardness tester fails to fully contact the material surface or has poor tactile sensation, it may result in inaccurate test results.
Interpretation of hardness values: A higher Shore hardness value usually indicates that the material is harder, while a lower value indicates that the material is softer, but the hardness standards and meanings may vary between different materials.
Summary:
Automatic Shore hardness tester is widely used for hardness testing of materials such as rubber and plastic, and can quickly and accurately measure the hardness value of materials. Testing according to international standards such as ISO and ASTM can ensure the reliability of test data. Ensuring the stability of the testing environment, surface cleanliness, and regular calibration of instruments are key to obtaining accurate hardness data.