Diameter measuring device

摘要

An apparatus for measuring the diameter of an object is disclosed. A rotatable wheel of known diameter capable of movement in three axes is contacted with an object capable of rotation. The wheel is attached to a shaft encoder which produces pulses as the wheel rotates. As the object is rotated, start and end reference marks are sensed and the pulses produced by the shaft encoder are counted. A microprocessor calculates the diameter of the object knowing the wheel diameter and counts per revolution and the counts per revolution of the object. The apparatus can be adapted to measure the internal or external diameter of smooth objects or the internal or external pitch diameter of threaded objects. The apparatus can also use a calibrated object to measure the diameter of a wheel of unknown diameter to allow the wheel to be used in later measurements.