CN2160884Y - Sensors for magnetoelectric parallel non-magnetic plating and coating thickness gauges - Google Patents

Abstract

The utility model provides a sensor of a magnetoelectric parallel non-magnetic plating and coating thickness measuring device, which installs a closely wound coaxial inductance coil and a compensation coil in a shielding electrode made of non-magnetic metal material The measuring electrode is made of soft magnetic material, the two coils are connected in series, the measuring electrode and the shielding electrode are connected by wires, the whole electrode is installed in a stainless steel shell with good electrical conductivity and mechanical strength, and insulating materials or resin are used between the layers filling. It is capable of continuous moving non-contact non-destructive testing. It is suitable for all industries involving the detection of non-magnetic coating thickness and the detection of non-ferromagnetic coating or coating thickness on the surface of magnetic materials. Such as the thickness measurement of anti-corrosion coating in the pipeline, the thickness measurement of automobile spray paint, etc.

Description

The utility model relates to a magnetoelectric parallel non-magnetic plating and coating thickness detection device, which can detect the thickness of non-magnetic material films, non-ferromagnetic metal films and non-metal films on ferromagnetic substrates, and can Continuous movement measurement to non-fixed point contact.

The thickness of the non-magnetic coating or coating on the ferromagnetic substrate, such as zinc, chromium, paint and other coatings on the surface of steel, and the thickness of gold, silver, copper, rubber, plastic and other films, generally ranges from tens of microns to several Between hundreds of microns, it is necessary to use a special coating thickness tester to measure. The currently used coating thickness detection instruments mainly include magnetoresistive and electromagnetic induction. These two instruments use the magnetostatic effect and eddy current effect of the sensor coil respectively to convert the thickness of the coating into electrical quantities for detection. The sensor probes of these two instruments are all contact type with the tested object. There is also a capacitive thickness gauge, which needs to fix the distance between the sensor and the substrate so that it cannot be continuously moved and measured; the thickness of the coating is measured by the acoustic wave backscattering method, which is still in the experimental stage; the high-voltage electric spark coating thickness detection equipment Continuous mobile measurement is possible, but it has the drawback of breaking through the coating. Therefore, the currently used coating thickness measuring instruments cannot perform continuous moving non-contact non-destructive testing.

The purpose of this utility model is to provide a non-ferromagnetic plating and coating thickness detection device with a new structure to realize non-contact continuous mobile measurement and point contact measurement at the same time.

The purpose of this utility model is achieved in that the non-magnetic coating thickness detection device of this novel structure, the key is the improvement of sensor. This sensor adopts magnetoelectric parallel connection, including a measuring electrode made of soft magnetic material, shielding electrode made of non-magnetic metal material and stainless steel shell. A coaxial inductance measurement coil and a compensation coil are closely wound on the measurement electrode. The inductance measurement coil is fixed at the lower end of the measurement electrode and connected in series with the coaxial movable compensation coil. The distance between the two coils is adjusted, and the compensation coil is supported by a spring. The shielding electrode is a cylinder made of non-magnetic metal material. The measuring electrode after the coil is wound is installed in the shielding electrode. The space between the measuring electrode and the shielding electrode is filled with an insulating gasket or resin. It is used for the measuring electrode and the shielding electrode. Wire connection. The installed shielding electrode and measuring electrode are installed in a stainless steel shell, and the space between the shielding electrode and the shell is also filled with insulating gasket or resin to ensure reliable insulation and mechanical properties.

Due to the above structure, a capacitive sensor is formed between the measuring electrode and the substrate, and its output signal is related to the distance d from the sensor to the substrate and the thickness h of the coating. The inductance coil and the compensation coil constitute a magnetoresistive sensor, and its output signal It is related to the distance d from the sensor to the substrate. The two signals are output in parallel, and after being processed by the signal processor, the influence of d is eliminated. In this way, the output signal of the circuit has a linear relationship with the coating thickness h, and has nothing to do with the change of the distance d, so that the coating thickness h can be directly measured, and the non-contact continuous moving measurement is realized.

The accompanying drawing is a schematic diagram of the sensor of this magnetoelectric parallel non-magnetic coating thickness measuring device.

In the figure, 1-measuring electrode, 2-shielding electrode, 3-shell, 4-inductance coil, 5-compensation coil, 6-insulating gasket or resin, 7-coating, 8-substrate.

The detailed structure of the magnetoelectric parallel non-magnetic coating measuring device proposed according to the utility model will be described in detail below in conjunction with the accompanying drawings and embodiments.

The measuring electrode (1) is made of soft magnetic material, and the coaxial inductance coil (4) and compensation coil (5) are closely wound on it. The coil (4) is fixed on the lower end of the measuring electrode (1), and is connected with the coaxial movable coil (5) Connect them in series, adjust the distance between the coil (4) and the coil (5), and use a spring to withstand the compensation coil. The shielding electrode is a cylinder made of non-magnetic metal material. The measuring electrode with a coil around it is put into the shielding electrode (2), and the gap is filled with an insulating gasket or resin (6). The measuring electrode (1) and the shielding electrode (2) Connect with wires. The installed two electrodes are housed in a stainless steel casing (3), and the casing (3) is required to have good electrical conductivity and mechanical strength. The space between the shielding electrode (2) and the shell (3) is also filled with an insulating gasket or resin.

In the actual test, the electrode and the surface of the measured substrate (8) may or may not be in contact, assuming that the distance between them is d, at this time, a capacitive sensor is formed between the measuring electrode (1) and the substrate, assuming the coated The layer thickness is h, and its output signal is related to the distance d from the electrode to the substrate and the coating thickness h; the inductance coil (4) and the compensation coil (5) constitute a magnetoresistive sensor, and its output signal is also related to the distance from the electrode to the substrate ( 8) is related to the distance d, the two signals are output in parallel, after being processed by the signal processor, the influence of d is eliminated, the circuit output signal has a linear relationship with the coating thickness h, and is not affected by the change of the distance d, so it can be directly measured The coating thickness h, therefore, can be measured both contact and non-contact, enabling continuous non-destructive testing.

The circuit of the magnetoelectric parallel non-magnetic plating and coating thickness measuring device provided by the utility model can be completed by measuring the capacitance circuit and the measurement inductance circuit, and there is no need to strictly calibrate the standard value of the capacitance and inductance, as long as the two are equipped with the same, can It is only necessary to compensate each other, so processing is easy. The device can carry out non-contact continuous moving measurement, which is convenient for large-scale automatic detection of the surface of the tested piece, without scratching the tested surface and not wearing the probe. This device is suitable for all industries involving non-magnetic plating and coating thickness detection, such as the thickness of plastic film or paper, and the thickness of anti-corrosion coatings in oil, gas, and water pipelines; it is suitable for all non-magnetic materials on the surface of ferromagnetic materials. Plating or coating thickness detection, such as the detection of car paint thickness.

Claims (4)

1. The sensor of 1, the parallel non magnetic plating of a kind of magnetoelectricity, coating thickness detector is made up of potential electrode, guarded electrode, coil, shell, insulating material etc.It is characterized in that, potential electrode (1) is close around telefault (4) and compensating coil (5), telefault (4) is fixed on the potential electrode (1), two coil coupled in series, install the potential electrode (1) behind the coil, pack in the guarded electrode (2), potential electrode (1) connects with lead with guarded electrode (2).
2. The sensor of 2, the parallel non magnetic plating of magnetoelectricity according to claim 1, coating thickness detector is characterized in that the material of potential electrode (1) is made with soft magnetic material, and the material of guarded electrode (2) is the nonmagnetic metal material.
3. The sensor of 3, the parallel non magnetic plating of magnetoelectricity according to claim 1 and 2, coating thickness detector is characterized in that between potential electrode (1) and the guarded electrode (2) with insulating cell or resin (6) filling and fixing.
4. The sensor of 4, the parallel non magnetic plating of magnetoelectricity according to claim 1, coating thickness detector is characterized in that said potential electrode and guarded electrode are installed in the stainless steel casing (3), and gap location is filled with insulating cell or resin (6).