Measuring head for air micrometer

A measuring head for an air micrometer, the measuring head configured to be mounted on a main spindle of a machine tool at the time of measurement and inserted into a bush hole of a bush attached to a work table of the machine tool, for measuring an amount of eccentricity between the bush hole and the main spindle,

• the measuring head characterized by comprising:
• a measuring-head body portion;
• and
• a measuring-head tip portion provided on a distal end of the measuring-head body portion, and configured to be inserted into the bush hole at the time of the measurement,
• the measuring head characterized in that
• one or a plurality of measurement air nozzles are formed in the measuring-head tip portion, the measurement air nozzles configured to blow measurement air to a gap between an outer peripheral surface of the measuring-head tip portion and an inner peripheral surface of the bush hole respectively through jetting openings in the outer peripheral surface at the time of measurement,
• individual measurement air supply passages corresponding to the respective measurement air nozzles are formed in the measurement-head body portion, and
• the measurement air is supplied to the measurement air nozzles respectively through the individual measurement air supply passages.