Paint thickness gauges are professionally used for detecting the paint thickness of second-hand cars. Second-hand car dealers can roughly understand the painting and sheet metal conditions of the car by testing the thickness of the car paint with a paint thickness gauge, and can indirectly judge the damage degree of the vehicle after an accident, providing quantifiable paint thickness data for car sellers and buyers. Linshang has 5 models of paint thickness gauges that support connecting to WeChat mini-programs and mobile phone APPs, which can generate test reports from test data and save or share the reports. They are small and portable, and easy to operate. There is also a three-color backlight display function: when the detected paint thickness is less than 170μm or the car material is non-metallic, the screen displays a white backlight; when the detected paint thickness is 170-350μm, the screen turns yellow; when the detected paint thickness is 350μm--3500μm or there is iron powder putty, the screen turns red.