Method and a device for determining the cross-sectional dimensions of the inner space of elongated, tubular bodies

• US RE30,088 E
• Filed: 01/04/1977
• Issued: 09/04/1979
• Est. Priority Date: 10/06/1970
• Status: Expired due to Term

• Current Assignee: Forsogsanlaeg Riso
• Original Assignee: Forsogsanlaeg Riso
• Inventors: Northeved, Allan, Lund, Svend A., Hansen, Hans N., Holst, Helge A.
• Primary Examiner(s): Ruehl, Charles A.
• Application Number:
  US05/756,674
• Time in Patent Office: 973 Days
• Field of Search: 73/67.5, 73/67.7, 73/67.8 R, 73/67.8 S, 73/622, 73/625
• US Class Current: 73/622
• CPC Class Codes: G01B 21/08 for measuring thickness
• CPC Class Codes: G01B 21/10 for measuring diameters
• CPC Class Codes: G01B 21/14 internal diameters of boreholes or wells E21B47/08
• CPC Class Codes: G01B 7/06 for measuring thickness measuring during the manufacture of coatings C23C14/54
• CPC Class Codes: G01B 7/312 for measuring eccentricity, i.e. lateral shift between two parallel axes

Abstract

When mapping out the internal cross-sectional dimensions of elongated, tubular bodies, correlated values of the external cross-sectional dimensions and wall thicknesses are measured along measuring lines from the outside of the body and the sum of the wall thicknesses measured along each measuring line is subtracted from the external cross-sectional dimension measured along the same or substantially the same measuring line. This avoids the use of measuring means in the interior of the tubular bodies, whereby the measuring can be carried out much faster and without the danger of injuring the internal surface of the bodies.

Claims

1. A method of mapping the cross-sectional dimensions of elongated tubular bodies by the use of measuring means along a measuring line fixed in relation to the measuring means and extending tranversely of the longitudinal axis of a tubular body, the method comprising the steps of:

providing relative movement between the tubular body and the measuring means to successively bring the measuring means into positions corresponding to the cross-sectional dimensions to be measured, activating the measuring means to measure along the measuring line the distances from points fixed in relation to the measuring means to the external surface of the tubular body, activating the measuring means to measure the wall thicknesses of the tubular body corresponding to the points of external surface to which the distances were measured, calculating from the measured values thus determined the external cross-dimension of the tubular body by subtracting the distances from said points fixed in relation to said measuring means to said external surface from the distance between said two fixed points, calculating from the measured values thus determined the internal cross-dimension of the tubular body by subtracting the distances from said points fixed in relation to said measuring means to said external surfaces and said wall thicknesses from the distance between said two fixed points, and registering the values thus calculated.

2. A device for mapping the cross-sectional dimensions of elongated tubular bodies, comprising measuring means for the external non-contact measuring of dimensions, said measuring means positioned to measure, along a measuring line which is fixed in relation to the measuring means, the distances from fixed points on said measuring line to the surface of a tubular member intersecting said measuring line as well as the wall thickness of the tubular body in close proximity to the points of intersection, means for providing a relative movement of the tubular body and the measuring means such that the measuring line extends transversely of the longitudinal axis of the tubular body and is successively brought into positions corresponding to the cross-sectional dimensions to be measured, means to activate the measuring means to measure the distance from each of said measuring means to the surface of the tubular body and the wall thicknesses at the positions desired to be measured, means to calculate from the measured values thus obtained .[.from.].the external and internal cross-dimensions of the tubular body, and means to register the values thus calculated.

3. A device as claimed in claim 2, wherein the measuring means are positioned to measure the correlated values of the distances from the fixed points to the surface of the tubular body and the wall thicknesses simultaneously along substantially the same measuring line.

4. A device as claimed in claim 2, further comprising means for briefly storing the measuring values first measured.

5. A device as claimed in claim 2, further comprising means for detecting the mutual angular position of the measuring means and the tubular body. .Iadd.

6. A method of mapping the cross-sectional dimensions of elongated tubular bodies by the use of ultrasonic measuring means located externally of and on diametrically opposite sides of a tubular body and along a measuring line fixed in relation to the measuring means and extending transversely of the longitudinal axis of a tubular body, the method comprising the steps of:

providing an energy coupling medium capable of transferring ultrasonic energy;

providing relative movement between the tubular body and the measuring means to successively bring the measuring means into positions corresponding to the cross-sectional dimensions to be measured with there being a helical path of relative movement between the tubular body and measuring means;

activating the measuring means to impinge ultrasonic energy through said medium in a normal direction on the exterior surface of the tubular member, whereby said energy is reflected back from that exterior surface to the energy producing means to measure along the measuring line the distances from points fixed in relation to the measuring means to the external surface of the tubular body;

activating the measuring means to impinge ultrasonic energy through said medium in a normal direction on the interior surface of the tubular member, whereby said energy is reflected back from the interior surface to the energy producing means to measure the wall thicknesses of the tubular body corresponding to the points of external surface to which the distances were measured; and

converting the reflected energy into electrical signals, processing said electrical signals into signals proportional to the outside diameter and wall thickness of the tubular member including calculating from the measured values thus determined the external cross-dimension of the tubular body by subtracting the distances from said points fixed in relation to said measuring means to said external surface from the distance between said two fixed points, calculating from the measured values thus determined the internal cross-dimension of the tubular body by subtracting the distances from said points fixed in relation to said measuring means to said external surfaces and said wall thicknesses from the distance between said two fixed points and registering the values thus calculated.