| 摘要 |
A measurement device comprises a carrier 20 adapted to be supported, in use, at least partially within a tubular body, a laser metrology unit 28 including means mounted on the carrier 20 whereby a laser beam 32 can be transmitted radially from the carrier 20 and whereby reflected light can be received, the carrier 20 being movable relative to the tubular body to adjust the position of the said means relative to the body, and a scale arrangement whereby the position of the carrier can be determined. |
