EP0160441A1
Expired / Lapsed
EP
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Apparatus and method for detecting and locating information about an event
Assignee: Raychem Corp
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Filing: 1985-04-11
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Granted: —
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Expires: 2005-04-11
Abstract
Abstract A method and apparatus for detecting and locating an event, i.e. a change in a variable, for example an increase in the concentration of a fluid as a result of a leak, a change in the physical position of a moveable member such as a valve, a change in temperature, or a change in pressure. The apparatus includes an elongate locating member (L) to which connection is made at the location of the event (E), and second and third members (S, R) to supply current to, and to measure the voltage drop down, the locating member (L). A reference impedance (Z R ) is connected in series with the locating member (L). When an event takes place, the voltage drop down, the locating member, from one end to the location of the event (E), and the voltage drop across the reference impedance are determined. A divider provides a ratio between the voltage drops and the location of the event is determined from that ratio. In this way, variations in the size of the current down the locating member (L) do not have an adverse effect on the accuracy of the location.
Inventors
- 👤 Louis M. Frank
- 👤 Mauro Bonomi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 10:32
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
255 words
A method for monitoring for the occurrence of an event, and for detecting and obtaining information about the event upon its occurrence, which method comprises providing a system in which, upon occurrence of the event, (1) electrical connection is made between an electrically conductive locating member and an electrically conductive second member; the connection to the locating member being effective at a first point whose location is defined by at least one characteristic of the event; the making of the connection enabling the formation-. of a test circuit which comprises that part of the locating member between the first point and a second point on the locating member having a known location, and in which an electrical current is transmitted between the first and second points on the locating member; that part of the locating member between the first point and the second point being connected in series with a reference impedance which has a known impedance and the current through which has a known relationship with the current through that part of the locating member; and the current, the reference impedance and the locating member being such that, by obtaining a ratio between a first voltage drop across the reference impedance and a second voltage drop between the first and second points on the locating member, the spatial relationship between the first and second points can be determined; (2) the ratio of the first and second voltage drops is obtained; and (3) information concerning the event is obtained from the ratio in step (2).
Claim 2
Independent Claim
255 words
A method for monitoring for the occurrence of an event, and for detecting and obtaining information about the event upon its occurrence, which method comprises providing a system in which, upon occurrence of the event, (1) electrical connection is made between an electrically conductive locating member and an electrically conductive second member; the connection to the locating member being effective at a first point whose location is defined by at least one characteristic of the event; the making of the connection enabling the formation-. of a test circuit which comprises that part of the locating member between the first point and a second point on the locating member having a known location, and in which an electrical current is transmitted between the first and second points on the locating member; that part of the locating member between the first point and the second point being connected in series with a reference impedance which has a known impedance and the current through which has a known relationship with the current through that part of the locating member; and the current, the reference impedance and the locating member being such that, by obtaining a ratio between a first voltage drop across the reference impedance and a second voltage drop between the first and second points on the locating member, the spatial relationship between the first and second points can be determined; (2) the ratio of the first and second voltage drops is obtained; and (3) information concerning the event is obtained from the ratio in step (2).
Claim 3
Dependent Claim
23 words
A method according to Claim 1, wherein the reference impedance has a resistance of at least 4,000 ohms, preferably 4,000 to 400,000 ohms.
Claim 4
Dependent Claim
37 words
A method according to Claim 1 or 2, wherein the reference resistance is 0.01 to 100 times, preferably 0.1 to 10 times, especially 0.5 to 2 times, the resistance of the whole length of the locating member.
Claim 5
Independent Claim
24 words
A method according to any one of the preceding claims wherein said electrical current is less than 12 milliamps, preferably 1 to 250 microamps.
Claim 6
Independent Claim
26 words
A method according to any one of the preceding claims wherein said electrical current fluctuates within a range from +4% to -4% from a reference amplitude.
Claim 7
Dependent Claim
250 words
Apparatus for use in a method as claimed in any one of claims 1 to 5, which apparatus comprises (1) an elongate electrically conductive locating member whose impedance from one end to any point on the locating member defines the spatial relationship between that end and that point; (2) an elongate electrically conductive second member; (3) an event-sensitive connection means which, upon occurrence of an event, effects electrical connection between the locating member and the second member, the connection being effective at a first point on the locating member which is defined by at least one characteristic of the effect; (4) an electrically conductive third member; (5) a reference impedance which has a known impedance and which is connected in series with said locating member; (6) a power source which, at least when occurrence of an event causes electrical connection to be made between the locating and second members, causes a current to be transmitted (i) between the first point and a second point which is at one end of the locating member, and (ii) through said reference impedance, the size of the current transmitted through the reference impedance having a known relationship with the current transmitted between the first and second points; (7) a first voltage-measuring device for determining a first voltage drop across said reference impedance, (8) a second voltage-measuring device for determining a second voltage drop between the first and second points; and (9) a divider which provides a ratio between said first and second voltage drops.
Claim 8
Dependent Claim
29 words
Apparatus according to Claim 6 wherein the power source is a constant current source whose current output fluctuates within a range from +4% to -4% from a reference amplitude.
Claim 9
Dependent Claim
19 words
Apparatus according to Claim 7 wherein the reference amplitude is less than 12 milliamps, preferably 1 to 250 microamps.
Claim 10
Dependent Claim
233 words
A device which is suitable for use in apparatus as claimed in any one of claims 6 to 8 and which comprises (1) three terminals (A,B,C); (2) a reference impedance which has a known impedance and which is connected between terminals A and C; (3) a first voltage measuring device connected across said reference impedance; (4) a second voltage measuring device connected across terminals A and B; (5) a divider which provides a ratio between said first and second voltage drops; whereby, an apparatus as claimed in Claim 6 is obtained when (1) terminal A is connected to one end of an elongate electrically conductive locating member whose impedance from one end to any point on the locating member defines the spatial relationship between that end and that point; (2) terminal C is connected to a power source, the power source also being connected to an elongate electrically conductive source member which is adjacent the locating member and which is connected to at least one event-sensitive connection means which, upon occurrence of an event, effects electrical connection between the locating member and the second member, the connection being effective at a first point on the locating member which is defined by at least one characteristic of the event; and (3) terminal B is connected to an electrically conductive return member,.the return member also being connected to the far end of the locating member.
References Cited (Backward Citations)
GB1178231A
Cited
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