ULTRASONIC INSPECTION SYSTEM

• US 3,766,775 A
• Filed: 02/22/1971
• Issued: 10/23/1973
• Est. Priority Date: 02/22/1971
• Status: Expired due to Term

• Current Assignee: Walter A. Gunkel
• Original Assignee: Walter A. Gunkel
• Inventors: Gunkel, Walter A.
• Primary Examiner(s): Queisser, Richard C.
• Assistant Examiner(s): Beauchamp, John P.
• Application Number:
  US05/117,676
• Time in Patent Office: 974 Days
• Field of Search: 73/67.7,67.8,67.9,71.5
• US Class Current: 73/623
• CPC Class Codes: G01N 2291/044 Internal reflections (echoes), e.g. on walls or defects
• CPC Class Codes: G01N 2291/2636 cylindrical from inside
• CPC Class Codes: G01N 29/0618 synchronised with scanning, e.g. in real-time
• CPC Class Codes: G01N 29/07 by measuring propagation velocity or propagation time of acoustic waves
• CPC Class Codes: G01N 29/11 by measuring attenuation of acoustic waves
• CPC Class Codes: G01N 29/30 Arrangements for calibrating or comparing, e.g. with standard objects

Abstract

A system for the ultrasonic inspection of metal objects is disclosed in which an object such as a pipe end is inspected simultaneously in adjacent parallel sections by a plurality of ultrasonic transducers, and the output of each of these transducers is converted to an electric signal proportional to the thickness of the object being tested adjacent the transducer. The outputs of all the transducers are combined in one instance to provide a recordable indication, such as on a chart recorder, of the electrical signal relating to the output of the transducer adjacent the thinnest wall of the member being inspected. The outputs of each of the transducers are also conducted to a second recording mechanism, which also is preferably a chart recorder. The recorder has one channel for each transducer, and each channel indicates the presence of a discontinuity of a predetermined magnitude. Means are provided for correlating the information concerning the wall thickness of the object being inspected and the information concerning the presence of a discontinuity of any one channel to provide information concerning location, depth and size of a flaw. The whole system may be provided on a portable stand for insertion into a pipe end to be inspected and a portable console to facilitate the inspection of large diameter pipe.

Claims

1. An ultrasonic inspection system comprising in combination:

a plurality of ultrasonic transducers for transmitting and receiving ultrasonic energy signals;

means mounting said transducers adjacent an object to be inspected to permit simultaneous inspection of adjacent sections of such an object;

impulse means connected to drive said transducers to provide transmitted ultrasonic energy signals to such an object being inspected;

a plurality of time measurement means each connected to said inpulse means and to one of said transducers to provide a plurality of electrical signals each proportional to a thickness of the object being inspected at one of said adjacent sections; and

indicating means connected to each of said time measurement means and including a plurality of event indicating means each responding to only one of said electrical signals to indicate the presence of discontinuities in any separate adjacent section, each such event indicating means providing such an indication when the level of its respective only one of said electrical signals deviates a predetermined amount from the level of such a signal representing normal wall thickness in the respective adjacent section, and thickness indicating means responding to each of said electrical signals to provide an indication of a thickness in at least one of said adjacent sections.

2. The system of 1 further including means for synchronizing said event indicating means and said thickness indicating means to permit each to be compared with a relative position on the object being inspected.

3. The system of claim 1 wherein said thickness indicating means is an analog chart recorder.

4. The system of claim 3 wherein said event indicating means further is an event chart recorder including a plurality of recording channels each connected to one of said time measurement means, each channel responding to one of said electrical signals of predetermined magnitude to provide a graphical display of discontinuities in one of said adjacent sections.

5. The system of claim 4 further including means for synchronizing the operation of said analog recorder and said event recorder to permit comparison on a time base of the presence of discontinuities with relative thickness.

6. The system of claim 5 wherein said analog recorder and said event recorder comprise one chart recorder having a plurality of recording channels, one of said channels being used as an analog recorder.

7. An ultrasonic inspection system for inspecting tubular members comprising, in combination:

portable means insertable into a tubular member to be inspected and supporting a rotatable shaft along the longitudinal axis of such a tubular member;

an ultrasonic inspection apparatus connected to said shaft to rotate about the inside diameter of such a tubular member, said inspection apparatus including a plurality of ultrasonic transducers for simultaneously inspecting adjacent circumferential bands of such a tubular member as the apparatus is rotated by said shaft;

means responding to the output of each of said transducers to provide a plurality of electrical signals each being proportional to a thickness in the wall of one of said circumferential bands; and

recording means responding to each of said electrical signals to provide a recordable indication of the condition of the tubular member in the circumferential bands being inspected, said recording means including thickness recording means; and

means for combining and responding to each of said electrical signals and connected to said thickness recording means to provide a recordable indication proportional to the smallest of said electrical signals.

8. The system of claim 7 wherein said recording means further includes a plurality of event recording means;

and further including level detector means responding to each one of said electrical signals when greater than a predetermined difference from the value of such an electrical signal representing substantially normal wall thickness of the member being inspected, to provide a distinctive recordable indication.

9. The system of claim 8 further including means for synchronizing the operation of said thickness recording means and said event recording means to permit the indications from each to be correlated with a circumferential position at which they occur on said tubular member.