| 摘要 |
<p>A metrological instrument determines a surface profile or form of a surface (61) of a workpiece (60) by effecting relative movement between a probe (11, 12) and the surface (61) so that the probe follows and is displaced by changes in the surface topography. A measure of the displacement of the probe as it follows the surface is obtained by a displacement provider which may be an interferometric gauge (35). Instead of making a measurement along a single measurement path over the surface (61), respective measurements are made on sections (61d and 61e or 61g and 61h) of that measurement path to obtain corresponding measurement data sets and these measurement data sets are independently positioned or aligned to a reference data set. The reference data set may be obtained by a measurement made on another section (61c) of the measurement path (61), on another measurement path (61f) over another surface (62a and 62b) of the component or on another measurement path over a surface on which the component is located. The aligned measurement data sets are then merged together to form a profile of the surface.</p> |
