| 摘要 |
A micrometer 3 which comprises: two contact surfaces 10, 11 such as contact surfaces of respective pins/ feeler pins, adapted to be abutted against an object. The contact surfaces are disposed a known distance 2C apart. The micrometer is arranged to measure a distance between a location on a surface of the object and a point whose location relative to the contact surfaces is known. The micrometer can output information from which the distance of the location on the surface of the object from a vector connecting points at which the two contact points 10, 11 abut the surface is determined. A wave emitter and receiver such as a laser head (1, fig. 2) may be located between the two contact surfaces 10, 11 to emit waves to a location on the surface of the object, and receive the reflected waves from that location. The wave may be a light wave, or a sound wave. A processor, which may be part of the receiver/emitter, may control the emitter. The processor may be a computer that calculates the dimension of the object from the output of the receiver. The object may have a circular cross-section or a cross-section in a shape of an arc whose diameter is to be determined. |
