Automobile paint thickness measuring apparatus and method

Abstract

The invention relates to an automobile paint thickness measuring apparatus and method. The apparatus comprises a U-shaped iron core, a phase lock amplification circuit and an A / D conversion module. The U-shaped iron core is embedded by a tunnel junction magnetic sensor, and is winded by a plurality of turns of field coils which are in connection with a constant current source; the output terminal of the tunnel junction magnetic sensor is in connection with the phase lock amplification circuit; the phase lock amplification circuit is in connection with the A / D conversion module; the A / D conversion module is in connection with a single chip microcomputer. The tunnel junction magnetic sensor samples signals; the field coils are in connection with constant current signals of 1KHz square waves; the output terminal of the tunnel junction magnetic sensor outputs voltage signals of the 1KHz square waves; the voltage signals are inputted into the phase lock amplification circuit to be converted into volt level signals, which are then converted by the A / D conversion module and are finally calculated by the single chip microcomputer. The apparatus and method employ the nanometer level tunnel junction magnetic sensor and weak signal phase lock treatment technologies to realize a plurality of functions such as paint thickness measurement and data transmission, and have the advantages of small size, high precision, low energy dissipation, etc.

Description

technical field [0001] The invention relates to an automobile paint surface thickness measuring device and a method thereof, belonging to the technical field of paint surface thickness measurement. Background technique [0002] The thickness and uniformity of automobile paint surface are the main factors affecting the visual effect of vehicle appearance and vehicle maintenance. Measuring the thickness and uniformity of automobile paint surface is beneficial to control the quality of vehicle painting. [0003] At present, the methods for measuring the thickness of automobile paint surface are: lever micrometer method, light transmission method, ultrasonic method and magnetic measurement method. [0004] The above measurement method has the following disadvantages: the current transformer has an iron core, and the output current is non-linear; the measurement error is large, and the phase deviation is an inherent defect of the traditional transformer; the measurement range is ...

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Problems solved by technology

[0004] The above measurement method has the following disadvantages: the current transformer has an iron core, and the output current is non-linear; the measurement error is large, and the phase deviation is an inherent defect of the traditional transformer; the measurement range is small, the frequency band used is narrow, and there are many varieties and specifications; the volume is large , heavy weight, high price

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