Apparatus for measuring the waviness of a workpiece surface

摘要

An apparatus for measuring the roundness and waviness of workpiece surfaces comprises a first peak-to-peak detector for detecting the absolute peak-to-peak value of the sum of a signal representative of the roundness error of the workpiece and a signal representative of the eccentric center of the workpiece. A low-pass filter passes only the low frequency eccentricity signal which is applied to a second peak-to-peak detector for detecting the absolute peak-to-peak value thereof. The outputs from both detecting devices are fed to an arithmetic means for effecting subtraction of the absolute value of the output signal from the second peak-to-peak detector from that of the first peak-to-peak detector thereby obtaining a signal representative of the peak or maximum amount of waviness of the workpiece surface at or near the point of maximum eccentricity error and unaffected by any eccentricity error.