EP0017682A2
Expired / Lapsed
EP
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Method and system for geophysical induction surveying
Assignee: GEOPROBE Ltd
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Filing: 1979-04-23
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Granted: —
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Expires: 1999-04-23
Abstract
Abstract The present invention relates to an inductive electromagnetic investigative method and is used for determining the presence of constituent mixtures of metallic compositions in a body The moethod comprises the steps of creating at least one electromagnetic field inductively coupling the body to be investigated with the field for exciting the body to produce current flow in any such mixtures which by virtue of their inherent non linear circuit characteristics, give rise to secondary electromagnetic field effects which are non linear with respect to the created field. Investigating any secondary electromagnetic field created by the excitation of the body for the presence of any such non linear secondary electromagnetic field effects, to determine if any such mixtures are present indivative of the nature of the body.
Inventors
- 👤 Michael R. Williams
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 00:47
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/72; G01V; G01V3/00; G01V3/08; G01V3/10; G01V3/104; G01V3/108
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
122 words
An inductive E.M. investigative method for determining the presence of constituent mixtures of metallic compositions in a body comprising the steps of creating at least one E.M. field, inductively coupling the body to be investigated with said at least one E.M. field for exciting the body to produce current flow in any such mixtures which by virtue of their inherent non-linear circuit characteristics give rise to secondary E.M. field effects which are non-linear with respect to the at least one created E.M. field, investigating any secondary E.M. field created by the excitation of the body by said at least one created E.M. field for the presence of any such non-linear secondary E.M. field effects to determine if any such mixtures are present.
Claim 2
Dependent Claim
122 words
An inductive E.M. investigative method for determining the presence of constituent mixtures of metallic compositions in a body comprising the steps of creating at least one E.M. field, inductively coupling the body to be investigated with said at least one E.M. field for exciting the body to produce current flow in any such mixtures which by virtue of their inherent non-linear circuit characteristics give rise to secondary E.M. field effects which are non-linear with respect to the at least one created E.M. field, investigating any secondary E.M. field created by the excitation of the body by said at least one created E.M. field for the presence of any such non-linear secondary E.M. field effects to determine if any such mixtures are present.
Claim 3
Dependent Claim
31 words
An inductive electromagnetic investigative method as claimed in Claim 1, wherein any secondary electromagnetic field is investigated by receiver means essentially minimum coupled with said at least one created electromagnetic field.
Claim 4
Dependent Claim
31 words
An inductive electromagnetic investigative method as claimed in Claim 1 wherein the frequency of the at least one electromagnetic field is in the range of 1 hertz to 10 K hertz.
Claim 5
Dependent Claim
31 words
An inductive electromagnetic investigative method as claimed in Claim 1 wherein the frequency of the at least one electromagnetic field is in the range of 1 hertz to 2.5 K hertz.
Claim 6
Dependent Claim
45 words
An inductive electromagnetic investigative method as claimed in Claims 1, 2, or 3, wherein the at least one electromagnetic field is created by transmitting an essentially pure sine wave and wherein any secondary electr- magnetic field is investigated at harmonics of said pure sine wave.
Claim 7
Dependent Claim
28 words
An inductive electromagnetic field is investigative method as claimed in Claim 4, wherein said secondary electromagnetic field is investigated at the third harmonic of said pure sine wave.
Claim 8
Dependent Claim
31 words
An inductive electromagnetic investigative method as claimed in Claims 1, 2 or 3, wherein two electromagnetic fields are created having different frequencies and investigating said secondary field at the beat frequencies.
Claim 9
Dependent Claim
31 words
A method as defined in Claim 4 including subjecting the body to be investigated to a further different stimulating E.M. field which amplify the non linear effects due to the mixtures.
Claim 10
Dependent Claim
34 words
An inductive E.M. investigative method as defined in Claim 4 including further subjecting the body to be investigated to an intermittent D.C. E.M. field to enhance the harmonic response in the secondary E.M. field.
Claim 11
Dependent Claim
45 words
An inductive E.M. investigative method as defined in Claim 1 including creating two E.M. fields one of which has a frequency of 50 hertz to 5 K hertz and the second field has a substantially lower frequency in the range of .1 to 40 hertz.
Claim 12
Dependent Claim
26 words
An inductive E.M. investigative method as defined in Claim 1 for use in determining the presence of weld faults and other discontinuities in rods and pipelines.
Claim 13
Dependent Claim
31 words
An inductive E.M. investigative method as defined in Claim 1 including further analysing the phase characteristics of any uncovered non linear secondary field effects to indicate the nature of the mixtures.
Claim 14
Independent Claim
129 words
A system for an inductive electromagnetic investigative method for determining the presence of constituents mixtures of metallic compositions in a body comprising means for creating at least one electromagnetic field which is inductively coupled to the body to be investigated for exciting the body to produce current flow in any such mixtures which by virtue of their inherent non linear circuit characteristics, give rise to secondary electromagnetic field effects which are non linear with respect to the at least one created electromagnetic field and receiver means for investigating any secondary electromagnetic field created by the excitation of the body by the said at least one created electromagnetic field for investigating the presence of any such non linear secondary electromagnetic field effects to determine if any such mixtures are present.
Claim 15
Independent Claim
129 words
A system for an inductive electromagnetic investigative method for determining the presence of constituents mixtures of metallic compositions in a body comprising means for creating at least one electromagnetic field which is inductively coupled to the body to be investigated for exciting the body to produce current flow in any such mixtures which by virtue of their inherent non linear circuit characteristics, give rise to secondary electromagnetic field effects which are non linear with respect to the at least one created electromagnetic field and receiver means for investigating any secondary electromagnetic field created by the excitation of the body by the said at least one created electromagnetic field for investigating the presence of any such non linear secondary electromagnetic field effects to determine if any such mixtures are present.
Claim 16
Dependent Claim
19 words
A system as defined in Claim 13, wherein such transmitting means comprises a signal generator and a transmitting loop.
Claim 17
Dependent Claim
27 words
A system as defined in Claim 14, wherein said receiving means selected from the group of receiving means consisting of receiver coils, fluxgate, magnaometer and cryogenic devices.
Claim 18
Dependent Claim
19 words
A system as defined in Claim 15, wherein the transmitting loop is stationery and the receiving means is portable.
Claim 19
Dependent Claim
28 words
A system as defined in Claim 16, wherein the transmitting loop and receiving means are both portable and are carried with one another in a fixed, constant relationship.
References Cited (Backward Citations)
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