Abstract:
A method and apparatus for utilizing flexural excitations to characterize and/or image a cased well is disclosed. Various applications of the method and apparatus are also discussed.
Abstract:
A new ultrasonic method for measuring wall thickness and detecting material flaws in natural-gas pipelines (30), risers, and similar structures. The method is inherently suitable for the task, because it relies on the use of the natural gas (G) as the coupling fluid for transmitting the probing ultrasonic signals into and out of the pipe wall. Furthermore, the method facilitates the operation of the inspecting from the inside of the pipe (30). An experimental apparatus is also described. Significantly, it is shown that by the use of a diplexer (18), the same transducer (15) can be used to generate and detect the probing ultrasonic signals. The same configuration is used in commercial ultrasonic inspecting of oil pipelines where oil is the coupling fluid; but until now this method could not be used in natural gas pipelines due to the low specific acoustic impedance of natural gas.
Abstract:
Die Erfindung betrifft eine Vorrichtung und ein Verfahren zur zerstörungsfreien Prüfung eines Prüfobjektes mittels Ultraschall, wobei Prüfkopfe als phasengesteuerte Gruppenschwinger ausgebildet sind und eine Mehrzahl verschiedene Größen aufweisende Schwinger (1) aufweisen, die derart angeordnet sind, dass große Schwinger für große Schallweglängen und kleine Schwinger für kleine Schallweglängen verwendet werden.
Abstract:
A device for acoustic measuring in a medium in a borehole such as velocity of sound in the medium or velocity of the medium, includes at least a first acoustic array situated in a first, slanted sidewall of a measuring area and operating to emit a series of acoustic waveforms across a measuring area. In one form, the device includes a second acoustic array situated in a second, slanted sidewall of the measuring area and operating to receive an acoustic signal resulting from the emitted series of acoustic waveforms or to receive said acoustic signal and emit a second series of acoustic waveforms. A the processor measures a time between when a predefined portion of one of the series of acoustic waveforms was emitted and when a predefined portion of the received acoustic signal corresponding to the predefined portion of one of the series of acoustic waveforms is received by the acoustic receiver, and correlates the measured time to a reference time, then outputs a correlation factor for determining the velocity of sound in the medium in the measuring area. The processor may also calculate transit time for the two emitted acoustic signals or echoes from the first emitted acoustic signals to determine medium flow velocity.
Abstract:
The invention relates to a test probe 10 for the non-destructive testing of a workpiece by means of ultrasonic sound. The test probe has an ultrasonic transducer 20 for the generation of an ultrasonic field, which is coupled acoustically to a delay line body 12, which is provided to be attached for a coupling of the ultrasonic field into the workpiece on a surface of the workpiece. Furthermore, the invention relates to a family of test probes as well as to a testing device for the non-destructive testing of a workpiece by means of ultrasonic sound, with a test probe 10, whose ultrasonic transducer 20 has a majority of independently controllable individual oscillators. Furthermore, a control unit 50 is provided, which is equipped to control the individual oscillators of the ultrasonic transducer 20 with phase accuracy in such a way, that a sound field rotationally symmetrical to the central beam is generated. The test probe or the family of test probes and the testing device are suitable in particular for the angular intromission of sound or for a utilization on curved workpiece surface areas.
Abstract:
Die Erfindung betrifft ein Verfahren und eine nach dem Verfahren arbeitende Vorrichtung zur Bestimmung eines Dichteprofils eines in einem Volumen (10) befindlichen Mediums (12), mit folgenden Schritten: als Signal wird ein Impuls definierter Bandbreite, insbesondere ein Ultraschallimpuls (18), durch das Medium (12) gesendet, wobei sich eine spektrale Zusammensetzung des Signals zumindest mit einer lokalen Dichte ρ(x) des Mediums (12) ändert, wobei sich die lokale Dichte ρ(x) als Quotient zweier frequenz- und ortsabhängiger Größen, nämlich akustische Impedanz Z(ω, x) und Schallgeschwindigkeit c(ω, x) ergibt und wobei sich das Dichteprofil durch eine Zusammenfassung der ermittelten lokalen Dichten ρ(x) ergibt.