Why does the coating thickness gauge produce inaccurate data during measurement
When using a coating thickness gauge for measurement, it is advisable to use the material being measured as the base for zero adjustment, in order to prevent measurement errors caused by different materials leading to different magnetic conductivity. Wait until the same part of the tested material is zeroed, and then perform measurements on the same part, such as zeroing separately at the edge and middle of the side workpiece.
When using a coating thickness gauge for measurement, attention should also be paid to maintaining the probe and the measured material surface perpendicular to avoid significant errors. If the measurement is at the same point, the probe can be moved at least 10 centimeters away each time, and the measurement can be carried out after a few seconds to avoid magnetization of the material being measured and affecting the measurement results.
The outer surface of the coating thickness gauge used for zero adjustment must be kept as smooth as possible. If the outer surface is not smooth, the average value should be taken depending on the situation, as the roughness of the outer surface has a significant impact on the measured values. Different structures should be measured separately by zero adjustment. The plane should be adjusted to zero on the side face, and the concave surface should be measured after zero adjustment. The convex surface should be measured after zero adjustment to prevent measurement errors due to different structures.
Temperature compensation measurement method for coating thickness gauge
The temperature compensation measurement method for coating thickness gauge includes temperature coefficient calibration step, startup zero calibration step, and thickness measurement work step, and finally calculates the actual coating thickness dx value; The correlation between the electromagnetic field changes of the inductor coil and temperature is utilized, that is, to measure the value at infinity once during the measurement process. The temperature change coefficient at infinity is proportional to the temperature change coefficient when the measurement probe is close to the substrate of the object being measured. By utilizing this feature to achieve temperature compensation, temperature measurement errors can be greatly reduced. The measurement error of this method can be basically controlled within 1%, while our national standard currently requires it to be within 3%. Through comparison, the measurement accuracy of this method has reached the measurement accuracy of international brand machines, which is still at a very high level in China.
