Patent ID: 8504316
Filing Date: 2013-08-06
Classification: G01B

Abstract:
1. A method of calibrating a form measuring instrument for calibrating a position of a contact tip of the form measuring instrument in a direction along a Y-axis, the form measuring instrument including: a table for placement of a workpiece thereon, the table being rotatable about a Z-axis; the contact tip capable of contacting with the workpiece; and contact tip driving means configured to drive the contact tip in directions along at least an X-axis and the Z-axis among the X-axis, the Y-axis, and the Z-axis perpendicular to one another, the method comprising: performing tracing measurement of an inclined flat surface, a side surface of an inclined cylinder, or a side surface of an off-centered cylinder by rotating the surface to obtain a measurement value at each angular position of rotation of the table, the inclined surface and the side surface of the inclined cylinder each being a part of the workpiece obtained by inclining the workpiece placed on the table about the Y-axis, the off-centered cylinder having a center axis off-centered in the direction along the X-axis; obtaining an angular position of rotation of the table at which a smallest value among the measurement values obtained by the tracing measurement is detected, as an angular position of rotation with smallest detected value; and adjusting the position of the contact tip in the direction along the Y-axis based on the angular position of rotation with smallest detected value, wherein the contact tip driving means includes: