The surface plate sitting in your temperature-controlled inspection lab or on the factory floor, is the foundation upon which all of your dimensional measurements stand. Maintaining calibration and proper care for your granite surface plate, is key to ensuring that your products’ dimensional specifications are as accurate as possible. Allow us provide you with both the knowledge and expert calibration service that will enable you to obtain the most accurate measurements possible!

When calibrating a granite surface plate, the Repeat-O-Meter, Planekator, and Autocollimator are the precision instruments used in conjunction to define a surface plates accuracy . The repeat-o-meter is the instrument used to check the small wear spots that occur from normal everyday use such as the constant sliding of your parts and/or measuring gages on your granite plate. Both the planekator and autocollimator are used to check the corner to corner or overall flatness of a surface plate. According to Federal Specifications GGG-P-463c, each surface plate must pass both the repeatability and overall flatness test in order to be legally certified as "within tolerance". This tolerance is defined by the grade (AA-Laboratory, A-Inspection, B-Toolroom) and size of a given surface plate. To check and see what tolerance you are allowed on your plate, use the following formula: Grade AA (40 + diagonal [in inches] of surface plate squared/25) x 0.000001 in. Grade A is Laboratory Grade AA x 2 Grade B is Laboratory Grade AA x 4.