How to Use the Shore Tester

Shore tester is divided into mechanical and digital types. Type A is suitable for general rubber, synthetic rubber, soft rubber, polyester, leather, wax and other materials. Type C is suitable for microporous materials made of foaming agents in rubber-plastic co-extrusion and plastics. Type D is suitable for general hard rubber, resin, acrylic, glass, thermoplastic rubber, printing boards, fibers, etc.

Requirements for preparing test samples for Shore tester

The thickness of the rubber sample should not be less than 6mm, the width should not be less than 15mm, and the length should not be less than 35mm. When the sample thickness is less than 6mm, the same film can be used for overlapping measurement, but no more than 3 layers. The film should be parallel to the top and bottom during calibration. The durometer should be stored at a temperature of 23℃±5℃ for at least 1 hour before calibration. Requirements for plastic samples and test temperature: plastic samples should be square with a side length of 50mm and a thickness of 6mm. It is also allowed to use samples of 50×15mm. If possible, the sample should be adjusted at the laboratory standard temperature before testing. Comparative or series tests must be carried out at the same temperature; the surface of rubber and plastic samples should be smooth, flat, and free from defects such as mechanical damage and impurities.

Precautions before measuring with Shore tester

Before using the Shore tester, the pointer of the durometer should point to zero in the free state. If the pointer deviates from the zero position, you can loosen the upper right corner clamping screw, rotate the surface, and align it with the zero position. Then press the durometer on the glass plate. When the needle end of the pressure needle and the bottom surface of the presser foot are in close contact with the glass plate, the pointer should point to 100+/-0.5HA. If it does not point to 100+/-0.5HA, the pressure needle can be slightly pressed several times. If it still does not point to 100+/-0.5HA, the durometer cannot be used. If using it on the Shore tester test stand, you can move the handle to make the workbench rise to a fixed load weight, so that the pressure needle end and the pressure foot plane are in close contact with the glass workbench, and the pointer should point to 100+/-0.5HA. If it does not point to 100+/-0.5HA, you can adjust the adjustment screw on the workbench plane. If the pointer still does not point to 100+/-0.5HA after adjustment, it is best to send it to the production unit for adjustment.

Correct testing method for Shore tester

Place the sample on a sturdy flat surface, hold the durometer, and press the pressure foot of the mid-hole distance from the edge of the test block at least 12mm. Smoothly press the pressure foot on the sample without any vibration and keep the pressure foot parallel to the surface of the sample, so that the pressure needle can vertically penetrate the sample. The applied force must be sufficient to make the pressure foot and the sample fully contact. Unless otherwise specified, the reading must be taken within 1 second after the pressure foot and the sample are fully in contact. If reading at different intervals, it must be stated. Measure the hardness value at least 5 times at different positions at least 6mm apart from the sample, and take the average value.

Maintenance Common Sense of Shore tester and related accessories

Pay attention to frequently wipe and apply a small amount of anti-rust oil on the lifting shaft on the fixed load measuring stand and the bottom of the workbench to prevent rust. After the durometer is used, put it in the instrument box or instrument case and place it in a dry place to prevent dampness. After the durometer has been used for 35,000 times, it is recommended to check the relationship between the spring pressure and the pointer scale and the shape and size of the tip of the pressure needle after using it for about 10,000 times according to the regulations.

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