| 摘要 |
<p>A method of determining the centreline of a tube (10) by using a probe (30) that projects light towards light sensors (46,48) through a probe sensitive area at which a tube to be measured is positioned, the method comprising the steps of moving the probe to at least two positions mutually spaced along and in proximity to a length of tube to be measured; and positioning at least a part of the tube in the probe sensitive area at each of the positions; characterized by the steps of employing the probe at each of the positions to measure slopes of first and second tangents to the tube from points on the probe; and calculating from the measured slopes, and for each of the positions, sets of offsets of first and second points on the tube centreline relative to the probe.</p> |
