Light leakage and closed gap are the two main indicators of piston rings. At present, the detection of light leakage and closed gap of piston rings in China. The performance of the automobile piston ring has a decisive influence on the quality and working efficiency of the engine, because the piston ring is one of the important parts of the engine. To sum up, the importance and decisiveness of light leakage and closed gap detection of automobile piston rings. Automobile piston rings are mass-produced, requiring high efficiency, accuracy and reliability in piston ring testing. The working surface of the piston ring shall not have nicks, scratches, or peeling. The outer cylindrical surface and upper and lower end surfaces shall have a certain smoothness, the curvature deviation shall not be greater than 0.02-0.04 mm, and the standard sinking amount of the ring in the groove shall not exceed 0.15-0.25 mm, the elasticity and clearance of the piston ring meet the requirements. In addition, check the light leakage of the piston ring, that is, place the piston ring flat in the cylinder, place a small light bulb under the piston ring, and put a light shield on it, and then observe the light leakage gap between the piston ring and the cylinder wall. This shows whether the contact between the piston ring and the cylinder wall is good. 　　

If the piston ring is to be inspected manually: 　　 

1. The quality of manual inspection is unreliable; 　　 

2. Low work efficiency; 　　 

3. The labor intensity is too high for the laborers to bear.