Adjustable deck flatness detection patent product, Patent Number: 88201288 Technical Requirements: face, flatness of not greater than 0.01 is not parallel to any span of not more than 0.03mm. Type-A adjustable range detection of objects 50-600mm plate , flat foot, table, precision workpiece flatness -1 50-500mm B-flat, flat feet, table, precision flatness of the work of B-type -2 50-50mm features both B-1 can check C630 and other small lathes, grinders and other rail straightness, parallelism is not C-50-300mm flat, flat feet, table, precision workpiece flatness