| 摘要 |
PCT No. PCT/SE96/00084 Sec. 371 Date Aug. 13, 1997 Sec. 102(e) Date Aug. 13, 1997 PCT Filed Feb. 9, 1996 PCT Pub. No. WO96/25584 PCT Pub. Date Aug. 22, 1996Apparatus for determining the curvature of an elongated channel, such as a drill hole in rock for instance, wherein the apparatus includes a probe (1) which may be constructed for movement through the channel and to assume the curvature of the channel at the different positions into which the probe is moved along the channel, wherein the probe (1) includes means (3, 31, 10) for sensing the curvature of the probe, and thus also the curvature of the channel, between at least two longitudinally spaced positions (A, B) on the probe (1), and wherein the apparatus can be connected to means (10) for determining the extension of the channel by registering curvature of the probe, for instance in different positions of the probe along the channel. The probe means include an optical fibre section (31) which is connected to a flexible probe body (3) arranged in the probe (1), wherein the optical fibre section (31) extends parallel with and at a constant distance from the bending neutral axis (44) of the probe body (3), such that strain acting in the fibre section will constitute a measurement of the bending or curvature of the probe body (3) in an axial plane (41) that includes the fibre section (31). The optical fibre section (31) has two partial reflection means(8a, 8b; 22a, 22b), for instance gratings, at said positions (A, B) along the probe. Means (10) are connected to the optical fibre section for interferometric determination of the change in distance between the partial reflection means in the fibre section (31). Means (32, 10) are provided for compensating for the influence of temperature on the change in distance between the partial reflection means. |
