Roundness measurement device and control method

A method for controlling a roundness measurement device providing a rotation table on a base and measuring roundness of a measured object placed on the rotation table while rotating the rotation table wherein the method utilizes a roundness measurement device, the roundness measurement device including a detector main body;

• a displacer configured to displace the detector main body with respect to the base;
• a stylus having a base end rotatably supported on the detector main body and configured to change an angle position with respect to the detector main body using an external force;
• a contacter provided at a position so as to be contactable with the stylus due to displacement of the detector main body by the displacer;
• and a driving controller configured to control driving of the displacer, the method comprising:
• displacing the stylus to be proximate to the contacter;
• bringing the stylus into contact with the contacter;
• and
• rotating the stylus to a predetermined angle with respect to the detector main body.