Surface texture measuring apparatus and method

A surface texture measuring apparatus comprising:

• a measurement sensor configured to measure, without contact, a surface texture of an interior wall of a cylinder portion of a measurable object, while displacing in a normal direction of the interior wall at each measurement region into which the interior wall is divided in the circumferential direction of the cylinder portion;
• a normal direction displacer configured to displace, in the normal direction, the measurement sensor such that the measurement sensor measures the surface texture of a first measurement region;
• a circumferential direction displacer configured to displace the measurement sensor in the circumferential direction, after measurement of the surface texture of the first measurement region, such that the measurement sensor faces a second measurement region adjacent to the first measurement region in the circumferential direction;
• and
• a controller configured to adjust a normal direction measurement position for measuring the surface texture of the second measurement region while displacing the measurement sensor in the normal direction, the controller further configured to adjust the measurement position based on measurement results of the surface texture of the first measurement region.