Abstract:The micromorphology of valves of diaphragm gas meter influences the coordination of working surfaces,thereby influences leakproofness of valves.Based on evaluating leakproofness by surface topography,a new leakproofness detector for valves of diaphragm gas meter was designed,which was comprised of computer,laser distance measuring sensor,motion control box,XY motion platform,Z shaft lifting scaffold,and worktable.When detecting,the valve is placed on the XY motion platform and moves with the platform,the computer sets the motion trace and collects the changing height data of measured surface,through the software processing to realize the detection of micromorphology.The experimental result shows that the system is easy to operate and runs smoothly.The qualified rate of two dimensional assessment reaches 85%,the qualified rate of threedimensional assessment reaches 100%,and the shortest evaluation time is 10 s.The system can set threshold of valves,which is suitable for various types of valves,and has the ability to display the surface morphology of graphic and print the results.