In life,the corrosion of the steel structure like a van is often due to the insufficient thickness of the paint layer, so many people would like to check whether the coating thickness reaches the standard with the help of a paint thickness meter.As a measuring tool,the paint thickness meter is flexible and convenient.Therefore,it is widely used in metal processing, chemistry,processing,commercial inspection and other fields.
Don't underestimate such a seemingly simple measuring tool,there are very rich scientific principles behind the paint thickness meter.The paint thickness meter has probes with different frequencies and chip sizes inside,which can realize the measurement of different materials surface coating thickness.Through the probe,the instrument can make zero adjustment and two-point calibration,the automatic error adjustment can be performed.Different measurement methods are used. Among them,the two most commonly used measurement methods are magnetic induction measurement and eddy current measurement.
Magnetic induction thickness measurement method.This measurement method has high accuracy.When the probe of the paint thickness meter is in contact with the coating,the probe will form a closed magnetic circuit with the magnetic metal substrate,but the non-magnetic coating on the surface of the magnetic metal will obstruct the magnetic circuit,so that the change of the magnetoresistance occurs.By measuring the amount of change in the magnetoresistance,the thickness of the surface covering layer can be obtained.And eddy current thickness measurement method:this measurement method is less accurate than the magnetic measurement thickness method,mainly used to measure the thickness of non-conductive coatings on conductive materials.
The paint thickness meter can facilitate the rapid detection of paint film thickness in our daily work,but improper use will lead to inaccurate measurement results.Therefore,some requirements in the use of the paint thickness meter require attention:
1.Measure after calibration according to the measurement thickness of the test substrate.Before using the tool to measure,check whether the thickness of the base metal exceeds the critical thickness.If it does not,the paint thickness meter is calibrated before measurement.For some paint thickness meters that use the Hall principle,no calibration is required just simple zero adjustment can be used, such as Linshang paint thickness meters.
2.Select the measurement position.When using the instrument for measurement,try to avoid the upper part of the curved surface of the test piece and do not measure at positions such as edges, holes and inner corners.
3.Multiple readings are more accurate.During the measurement process, each reading of the instrument is not exactly the same,the reason may be that there are local differences in the film thickness of the test piece.Therefore,multiple measurements can be made in any given area.
4.Surface cleanliness:The paint thickness meter will be more sensitive to the attachments that hinder the probe and the surface of the cover layer.Therefore, remove the attachments on the surface before measuring to ensure that the measurement results are not affected by it.
5.Avoid magnetic field interference:The magnetic field generated by the surrounding environment will also seriously interfere with the magnetic thickness measurement, so try to avoid various electrical equipment and other environments when measuring again.
6.The probe keeps vertical measurement: The way the probe is placed also has a great impact on the measurement result. During the measurement, the probe should always remain perpendicular to the workpiece.
In short, after knowing the basic principle of the paint thickness meter and mastering its use and precautions, you can be at ease during use, making the paint thickness meter serve us better!