Pay attention to the following eight points when measuring thickness:
When conducting testing, it is important to note that the metal magnetism and surface roughness of the standard specimen should be similar to those of the test piece.
2. When measuring, it is important to ensure that the side head is perpendicular to the surface of the sample.
When conducting tests, attention should be paid to the critical thickness of the base metal. If the thickness is greater than this, the measurement will not be affected by the thickness of the base metal.
4. When measuring, attention should be paid to the influence of the curvature of the specimen on the measurement. Therefore, it is unreliable to measure on curved specimen surfaces.
5. Before measurement, pay attention to whether other electrical equipment around will generate a magnetic field, as it may interfere with the magnetic thickness measurement method.
6. When measuring, be careful not to measure at the inner corner or near the edge of the specimen, as sudden changes in the surface shape of a typical thickness gauge specimen are very sensitive.
7. Keep the pressure constant during measurement, otherwise it will affect the reading of the measurement.
8. During testing, it is important to ensure that the measuring head of the instrument is in direct contact with the tested object. Therefore, the ultrasonic thickness gauge should be used to remove any attached substances on the opposite side of the head.
Tips for calibrating thickness gauges
1. Using step test blocks, calibrate at the maximum and minimum values (or 1/2 of the maximum value of the thickness to be measured) when the thickness is close to the thickness to be measured;
2. Place the probe on a thicker test block and adjust the "sound speed correction" knob to make the thickness gauge display a reading close to the known value;
3. Place the probe on a thinner test block and adjust the "zero position correction" knob to make the thickness gauge display a reading close to the known value;
4. Repeatedly adjust to obtain correct readings at both ends of the measuring range, and the instrument is considered to have been debugged;
5. If the sound velocity of the material is known, the sound velocity value can be adjusted in advance, and then the "zero position correction" knob can be adjusted on the test block attached to the instrument to display the thickness of the test block, and the instrument will be debugged.
