Questions about the use of coating thickness gauges
1. Why is the coating thickness gauge sometimes inaccurate?
This is a rather general question. Because there are various reasons for the inaccuracy of the instrument. For the coating thickness gauge alone, 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 10,000 V, the measurement will be seriously disturbed. If it is very close to the electromagnetic field, there may be a crash phenomenon.
(2) Human factors. This often happens to new users. The reason why the coating thickness gauge can measure to the micron level is that it can take the small change of magnetic flux and convert it into a digital signal. If the user is not familiar with the instrument during the measurement of the instrument, the probe may deviate from the body under test, causing the magnetic flux to change and cause wrong measurement. Therefore, it is recommended that users and friends first master the measurement method when using the instrument for the first time. The placement of the probe has a great influence on the measurement. During the measurement, the probe should be kept perpendicular to the surface of the sample. And the probe should not be placed for too long, so as not to cause the interference of the magnetic field of the matrix itself.
(3) An appropriate substrate was not selected during system correction. The minimum plane of the substrate is 7mm, and the minimum thickness is 0.2mm. Measurements below this critical condition are unreliable.
(4) The influence of attached substances. The instrument is sensitive to adhering substances that prevent the probe from making intimate contact with the overlay surface. It is therefore necessary to secure the attachment substance to ensure direct contact between the probe and the overlay surface. When performing systematic correction, the surface of the selected substrate must also be bare and smooth.
(5) The instrument fails. At this time, you can communicate with technicians or return to the factory for repair.
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2. During the measurement process, why sometimes there are obvious deviations in the measurement data?
During the measurement process, due to the incorrect placement of the probe or the influence of external interference factors, the measurement data may be significantly larger. At this time, you can press and hold the CAL key to save the data from entering the data statistics.
3. How to calibrate the system?
The method and type of calibration are common problems for new users. System calibration, zero point calibration, and two-point calibration have actually been written in the manual, and users only need to read it carefully. It should be noted that when calibrating the iron base, it is best to measure several times to prevent wrong operations; the samples for system calibration should be carried out in order from small to large. If individual standard pieces are lost, you can find samples with similar values to replace them.
4. What is the cause of interference when booting up sometimes?
After the instrument is turned on, the measurement status arrow appears on the screen of the instrument and the measurement cannot be performed again, which means that the instrument has been interfered. There are two main reasons:
(1) When starting up, the probe is too close to the iron base, which is interfered by the magnetic field of the iron base.
(2) The probe is not inserted properly or the probe line is damaged.
