Eddy Current Thickness Gauge Principles and Characteristics

From:Linshang Time:2019/10/24 14:33:00 Browse:148
The eddy current thickness gauge can non-destructively measure the non-conductive coating thickness on non-magnetic metal substrates, such as paint, rubber, etc. We will introduce the principles and characteristics of the eddy current thickness gauges in this article.

Common coating thickness gauges can be divided into magnetic thickness gauges, eddy current thickness gauges, ultrasonic thickness gauges according to different measurement principles.The detailed principles and characteristics of the eddy current coating thickness gauge will be introduced here. 
   1.Principle of eddy current coating thickness gauge
    The coil core in the eddy current coating thickness gauge probe is usually made of a high-frequency material such as platinum-nickel alloy, which generates a high-frequency electromagnetic field in the coil by the current. After contacting of the conductor (metal substrate) at the probe and the bottom, eddy currents are formed on the metal substrate. The closer the probe is to the conductor (metal substrate),the larger the eddy current and vice versa. This eddy current will have a feedback effect on the coils in the probe. The magnitude of the feedback action can represent the distance between the probe and the conductor (metal substrate),that is,the non-conductive coating on the conductive metal substrate.Thickness.
    2.Characteristics of eddy current coating thickness gauge

The eddy current thickness measurement method is one of many measurement principles of the coating thickness gauge.The eddy current coating thickness gauge using a single eddy current method can realize nondestructive measurement of various non-conductive coating layers on a non-magnetic metal substrate.Thickness,such as paint,rubber,plastic,anodized film,etc.,It is often used to measure the coating on aircraft,ships,automobiles, doors and windows as well as various aluminum products.The anodized layer also has the thickness of the paint.
    The eddy current thickness measurement method can theoretically measure the thickness of the coating on the magnetic metal substrate.The calibrated instrument can measure the coating thickness with certain conductivity,but the requirements of this type of test on the substrate and the cover layer. Very high,so it is not recommended.If it is necessary to measure the thickness of the coating on the magnetic metal,it is recommended to use the instrument of magnetic thickness measurement principle.

eddy current coating thickness gauge

The instrument using a single eddy current thickness measurement method is not very wide, so gradually coating thickness gauges using both principles at the same time appears.This instrument uses both eddy current thickness measurement method and magnetic thickness measurement method to cover the measurement range of the eddy current coating thickness gauge and the magnetic thickness gauge.The common non-magnetic metal is aluminum and the common magnetic metal is iron.Therefore,this dual-principal instrument is the coating test of iron and aluminum.Common iron-aluminum dual-purpose thickness gauges are QNix, TQC and Linshang coating thickness gauges.The appearance of these instruments also makes the thickness measurement of the coating become simpler and more efficient.
     For more information about the coating thickness gauge, please refer to https://www.linshangtech.com/tech/tech600.html

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