MEASURING OF SURFACE PROFILE

PURPOSE:To reduce the cumulation of a measuring error possessed by each distance sensor, by solving a simultaneous linear equation containing the displacement amount and oscillation amount of each distance sensor and the profile value based on the temporary line at the measuring point of an object to be measured as unknown numbers. CONSTITUTION:Distance sensors 31, 32, 33 measure the spaced-apart distances between the surface of a rolling roll 1 and sensor main bodies 31b, 32b, 33b and the measured result is inputted to an operation apparatus 10. When the operation apparatus 10 counts the pulse from a rotary encoder 6 and detects that a measuring unit 3 was moved over the distance L between the adjacent distance sensor arrangements, said operation apparatus 10 successively reads the outputs of the distance sensors 31, 32, 33 to accumulate the same. The displacement amount, the oscillation amount and the surface profile value during the movement of each distance sensor are calculated on the basis of the accumulated data to obtain a simultaneous linear equation containing said values as unknown numbers and this equation is solved to calculate the surface profile of the object to be measured.