Paint film hardness tester

There are mainly the following common working principles:
Pencil hardness method: Use pencils of different hardness to perform scratch tests on the surface of the paint film to determine the pencil hardness level that the paint film can withstand. The hardness of pencils is divided into multiple levels from soft to hard, such as 6B, 5B, 4B...H, 2H, 3H, etc. During the test, fix the pencil at a certain angle and pressure, and scratch it at a uniform speed on the surface of the paint film to observe whether the paint film is scratched or leaves marks, so as to determine which pencil hardness level the hardness of the paint film is equivalent to.
Pendulum hardness method: The damping time of the pendulum swinging on the surface of the paint film is used to measure the hardness of the paint film. The swing of the pendulum is subject to the resistance of the paint film. A paint film with higher hardness will make the swing damping time of the pendulum shorter, and vice versa. By measuring the pendulum damping time of different hardness standard plates and the tested paint film, and comparing them, the hardness value of the paint film is obtained.