Research Of Coating Thickness Gauge Based On LDC1000

In modern industry,the application of coating on metal parts is more and more extensive.The thickness of the coating has a great influence on the performance and life of the workpiece.Therefore,it is beneficial to study the measurement of thickness of the coating in engineering.In the production,due to eddy current detection being simple,quick and high sensitivity,eddy current coating thickness gauge is widely used.In this paper,a new coating thickness gauge is designed using the LDC1000 chip.It makes measuring according to the relationship between the thickness and the parallel resonant impedance.The thickness gauge can establish different measurement functions basing on the different metal substrates,and then achieve the measurement of the thickness of coating on different substrates.In the same time,the thickness gauge can communicate with the PC side.Therefore,through the use of the computer,the measurement information can be displayed and applicated and this thickness gauge can be conveniently calibrated.In addition,the thickness gauge is low cost,easy to operate.This paper first introduces the principle of thickness measurement of coating,and obtains the basic law between the parallel resonance impedance and the lift-off(thickness).According to the law,this paper establishes a model of lift-off and the parallel resonance impedance,and designed a program to demonstrate the model.By this model,the detection probe being suitable for LDC1000’s measurement is designed,and the effect of metal substrate thickness on the measurement accuracy is studied.Then,in the paper the circuit of the thickness gauge was designed,and the construction of the relevant hardware is completed.In the software system,through the realization of the information read,smooth processing and other functions,the calculation and display of the thickness information are achieved.Then the experiment was carried out using this thickness gauge and the acquired data were analyzed.According to the experiment and analysis,the relationship between the thickness and parallel resonance impedance is established.After the temperature compensation,this function is simulated and experimentally verified,and the reliability of the function is proved.Finally,through experiments on other metal substrates,it is verified that the thickness gauge can be used for measurement on more than one metal substrate.