Patent ID: 9027255
Filing Date: 2015-05-12
Classification: G01B

Abstract:
1. A micrometer comprising: a U-shaped frame; an anvil fixed to one end of the frame; a spindle that is screwed to the other end of the frame and is advanced and retracted relative to the anvil; an encoder that detects a displacement of the spindle; a display that displays a measurement value obtained by processing a detection value detected by the encoder; a deformation detecting section that detects a deformation of the frame; a storage that stores as a compensation factor a change amount of the detection value per a unit deformation detected by the deformation detecting section; a compensation factor setting section that, while the spindle is in contact with the anvil or an object to be measured by different first and second measurement forces, retrieves a first detection value and a second detection value which are detected by the encoder and a first deformation and a second deformation which are detected by the deformation detecting section, calculates a value obtained by dividing a difference between the first and second detection values by a difference between the first and second deformations as the compensation factor, and stores the compensation factor in the storage; and a compensator that compensates the detection value based on a difference between a zeroset-time deformation that is detected by the deformation detecting section when a command for zeroset is given and a measurement-time deformation that is detected by the deformation detecting section in measurement, and based on the compensation factor stored in the storage.