METHOD AND INSTRUMENT FOR MEASURING THICKNESS OF SHEET MEMBER

摘要

PROBLEM TO BE SOLVED: To provide a method by which the measurement of the thickness of a sheet member made of a new material can be started quickly even when the material of the sheet member to be measured is changed to the new material. SOLUTION: In a method for measuring thickness of sheet member, a measuring reference value is measured by holding a first reference gauge 3 at the projecting position of the measuring light 1a of each optical displacement gauge 1 and projecting the measuring light 1a of each gauge 1 upon the reference gauge 3 and another measured value is obtained by holding a second reference gauge 4 at the projecting position of the measuring light 1a instead of the first reference gauge 3 and projecting the light 1a upon the gauge 4. Then a computing element 2 is set so that the difference between the measured reference value and the measured value may become the difference between the thickness of the first and second gauges 3 and 4. When the thickness of another sheet member made of a different kind of material is measured after completing the measurement of the thickness of a sheet member A, the computing element 2 is set in the way by using a reference gauge of the same material as that of the hew sheet member or a material having the same optical characteristic as that the material of the sheet member A has.