Why are instruments sometimes inaccurate?
This is a rather general question. Because there are various reasons for the inaccuracy of instruments. For a single coating thickness gauge, there are mainly the following reasons that cause inaccurate measurement.
(1) Interference of strong magnetic field. We have done a simple experiment, when the instrument works near the electromagnetic field of about 10 thousand V, the measurement will be seriously disturbed. If you are very close to the electromagnetic field, there may be a crash.
(2) Human factors. This often happens to new users. The reason why the coating thickness gauge can measure micron level is that it can take small changes in magnetic flux and convert it into digital signals. If the user is not familiar with the instrument in the process of measuring, the probe may deviate from the measured body, which will change the magnetic flux and cause wrong measurement. Therefore, it is suggested that users and friends should master the measurement method first when using this instrument for the first time. The placement of the probe has a great influence on the measurement, and the probe should be kept perpendicular to the surface of the sample during the measurement. And the probe should not be placed for too long, so as to avoid the interference of the magnetic field of the matrix itself.
(3) No suitable matrix was selected during system correction. The minimum plane of the matrix is 7mm, and the minimum thickness is 0.2 mm. Below this critical condition, the measurement is unreliable.
(4) The influence of attached substances. This instrument is sensitive to the attached substances that prevent the probe from contacting closely with the surface of the coating. Therefore, the attached substances must be removed to ensure that the probe is in direct contact with the surface of the coating. When carrying out systematic correction, the surface of the selected matrix must also be bare and smooth.
(5) The instrument is out of order. At this time, you can communicate with technicians or return to the factory for maintenance.
