There are several major sources of measurement error in coating thickness gauges
Coating thickness gauge adopts new magnetic sense technology, which is Hall effect, by studying the relationship between Hall voltage and working current, measuring the magnetic field of electromagnet, magnetic permeability, studying the relationship between Hall voltage and magnetic field. This magnetic field is then becomes regular. The principle is used in the coating thickness gauge above there is no need to adjust the test piece. Especially when measuring the arc or concave surface of the product is more simple and convenient to use.
Coating thickness gauges use electromagnetic induction to measure the thickness of coatings. The probe located on the surface of the part generates a closed magnetic circuit, which changes to varying degrees as the distance between the probe and the ferromagnetic material changes, causing changes in the magnetoresistance and inductance of the probe coil. This principle can be used to accurately measure the distance between the probe and the ferromagnetic material, i.e. the coating thickness.
Coating thickness gauge is not used for a long time to be regularly charged and discharged to prevent the battery lock up, for some small workpiece or special cover layer thin workpiece is recommended to use continuous measurement.
Coating thickness gauge measurement error caused by several major reasons:
1. Thickness gauge is measured by the structure of different materials, different shapes. In the different structure of the workpiece, the magnetic field distribution will be different with the structure, shape, will produce measurement error.
2. The measured material itself contains magnetism. Some materials in the processing or certain process requirements, so that the measured material has a residual magnetic field. Because of its uneven distribution, so the resulting measurement error is not consistent, there will be in the same workpiece on some parts of the measurement value suddenly become larger or smaller.
3. Different parts of the same material may also produce changes in the magnetic field, such as the edge of the material and the middle of the region, the distribution of the magnetic field is not the same, will produce measurement errors.
4. Different nature of the measured material, its magnetic flux will be different, which is also one of the reasons for the error.
5. Different size and thickness of the material can also lead to measurement errors.
6. The surface of the measured material is not smooth enough, which is also a cause of error.
