Preparation before using the hardness tester

1. The surface of the part to be tested be flat, clean, free of dirt, scale, dents, and obvious machining marks.

2. The thickness of the test piece should not be less than mm, and the size of the test piece should ensure that 5 points are tested on the same surface, with a distance of not less than 10mm between the center edge of each test point.

3. Data from test pieces with cracks in the indentation or marks on the back are invalid.

4. The test piece should placed stably on the test table. During the test, the test piece should not move, and the test force should be applied vertically to the test piece.

5. the test piece is cylindrical, a "V"-shaped test table is required.

6. Select the appropriate test table according to the shape and size of the test piece If the test piece is irregular in shape, a special fixture can be made according to the specific geometry to ensure reliable indications for the hardness test.

7. The surface of ball punch shall be free of dust, oil, and oxides. The ball punch shall not deform during the hardness test and should be undamaged after the test.

Operating sequence of the hardness tester

1. Connect the power supply, turn on the boat switch, and the digital display of the touch screen will be connected.

2. According to the hardness and hardness of the material to be tested, select the scale according to Table 2, and turn the variable load handwheel clockwise to determine the test force. The Rockwell hardness value of plastics should be as close as possible to the range of 50-115, and a few materials should not exceed 25 in this range. If a material is tested with two scales and the resulting values are both within the limit, the smaller scale should be used. The same material should use unified scale.

3. Insert the ball punch into the main shaft hole, close to the bearing surface, facing the handle of the punch, and loosen the screw slightly Place the test piece on the test table.

4. Rotate the screw in the direction to raise and lower the lifting screw, and slowly press the hardness meter punch against test piece, without affecting the hardness indicator on the small dial from the black dot to the red dot, and at the same time, the long pointer rotates three times vertically to to "30". At this time, the initial test force is 98.07N. The long pointer offset should not exceed 5 divisions. If it this range, it cannot be reversed. Change the position of the measuring point and do it again.

5. Turn the hardness meter dial to align the pointer with the "0" position.

6. Press the "Start" key on the touch screen, the motor starts to run, and the main test force is automatically added, with the test force holding time rising.The motor rotates and the main test force is automatically removed.

7. The total test holding time for the Rockwell plastic hardness is 15 seconds, and the length of time is selected by the up and down keys on the touch screen.

8. Wait another 15 seconds, theer sounds, and immediately read the hardness value indicated by the long pointer.

9. The number of times the Rockwell hardness value of the plastic is read and recorded, long pointer is transmitted to the "0" point after adding, and the main test force and the number of times the long pointer is transmitted after the main test force is removed are. The method for reading the hardness indication:

If the difference is zero, the scale reading plus 100 is the hardness value;

If the difference is1, the scale reading is the hardness value;

If the difference is 2, the scale reading is -100 is the hardness value.

10 Rotate the lifting screw in the opposite direction, lower the test table, change the test point, and repeat the above operation.

11. There should be no less 5 test points on each test piece. The inspection and test points of large volume parts can be appropriately reduced.

The above is the correct way to use the hardness t, which I hope will be helpful to everyone.