KR930002590B1 - Detective apparatus of liquid change - Google Patents

Abstract

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Description

Devices for detecting and detecting the presence of liquid

1 is a schematic circuit diagram of an apparatus and method of the present invention.

2 to 18 are schematic furnace diagrams of the method and apparatus of the present invention.

19 to 21 are graphs showing the voltage drop between the first point and the second point on the position detecting member according to the present invention.

22 to 23 are cross-sectional views of the device of the present invention.

* Explanation of symbols for main parts of the drawings

1: point 1 2: point 2

11: position detecting member 12: power supply member

14: voltage measuring device 15: power supply

16: return member 151: exclusive member

152: connection means

The present invention relates to an apparatus for detecting the presence of a liquid, for example a liquid leak.

There are several known methods for detecting the presence of a liquid. In such conventional detection methods, leakage from a stream line to a thermal barrier enclosing such a line, leakage from tanks and pipes containing corrosive or toxic chemicals or leakage of fluid under fluid or in a telecommunication or power system, or Very good detection of condensation. This known method not only transmits a signal when an event occurs, but also indicates the location of the event. But. Known methods of informing the location of events have several problems. For example, such methods use time-domain reflectometer technology (and therefore are expensive), which are practical and unknown along the path length of a variable when used over usefully long paths or affecting measurement accuracy (especially temperature). Electrical conductors with unreliable results under unreliable conditions, whose primary purpose is to carry current (e.g., telecommunications signals) under operating conditions, and thus have resistance and uniformity characteristics consistent with that purpose. And the event cannot be used to cause an electrical connection between two conductors through a connection which is a high or undetermined resistance, for example a connection element conducting with one ion. US Pat. Nos. 1,084,910, 2,581,213, 3,248,646, 3,384,493, 3,800,216, 3,991,413 and United Kingdom 1,481,850 and JP 3,001,150.0, 3,225,742. However, the conventional method is unsatisfactory because it is expensive and inaccurate. A simple and accurate method and apparatus have been developed for this purpose, and in its first aspect, the present invention provides an apparatus for detecting and detecting the presence of a liquid at a first point 1 along a long path, said apparatus Is,

(A) One sensor cable is provided, which follows the long path and includes the following.

(1) long detection member (11)

i) the detection member comprises a metal core 111 and an elongated jacket 112, the jacket electrically surrounding the core 111 and the jacket composed of a conductive polymer,

ii) the impedance from the second point 2 of the one end of the detection member to the first point 1 defines the position of the first point,

(2) a long power source member, which member is spaced apart from the member and has a metal core 121 and a long jacket 112, the jacket enclosing the core 121 electrically and made of a conductive polymer,

(3) Liquid sensing connection means, which means is placed between the detection member 11 and the source member and between the detection member 11 and the source member 12 of the first point 11 together with the liquid to be detected. Affects the electrical connection (E).

(B) the voltage measuring device 14, which determines the voltage drop between the first point 1 and the second point 2,

(C) power source 15, which is electrically connected to the second point 2 at the detection member when liquid is present at the first point 1,

(D) the return member 16, which forms part of the sensor cable and is electrically connected to the second point 2 at one end of the detection member 11 via the voltage measuring device 14; and (ii) a second end electrically connected to the opposite end of the detecting member 11, wherein the return member 11 is insulated unlike the detecting member 11, where the detection member is due to the presence of the liquid. Affects the electrical connection E between (11) and the power supply member 12, which (a) forms a detection circuit, which comprises (i) the connection E and (ii) the first point ( A detection member and (iii) a power source between 1) and the second point (2), the power source causing a current of known magnitude to be transmitted between the first point (2) and the second point (2). (b) forming a reference circuit, the circuit comprising a voltage measuring device 14, a detecting member 1 and a returning member 16, wherein the voltage measuring device 14 has an impedance of another component of the reference circuit. Very high compared to It has an impedance.

If a single or very short connection E is made between the detection member and the source member due to the presence of the liquid, the "first point" will be easily identified since it is the only connection point. However, if the event causes a connection over two or more spaced intervals and / or over a certain length of the position-detecting member, then the "first point", ie the point from which the position is determined from the measured voltage drop, is some intermediate point. Will be If the connection is made at two or more positions spaced apart by a certain distance, the first point may be an unconnected point between the position detecting member and the power supply member. For this reason, connection with the position detecting member is often described herein as occurring at the first point.

The present invention overcomes one or more disadvantages of the prior art methods. An especially important advantage for many applications is that the information obtained is independent of the connection (E) impedance with the position detection member. In other words, even if a substantial unknown change occurs in the connection impedance, the obtained information is the same.

In order to make the description clear, the matters related to the present invention will be described in parts. However, the relationship between the parts of the present invention is quite important, and you should read this specification in consideration of such a relationship. Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

Basic electrical characteristics of the present invention can be easily implemented with reference to FIG. 1, which schematically illustrates various preferred methods and apparatus of the present invention. The long position detecting member 11, the long power supply member 12, the voltage measuring device 14, the power supply 15, and the long returning member 16 are shown in FIG. The power supply member is electrically connected to one end of the position detection member via a power supply, and in the absence of liquid there is no other electrical connection between the position detection member and the power supply member. Although not shown in FIG. 1, a conductive event sensitive connecting means is located between the power supply member and the position detecting member at any position where liquid is present, and the event sensitive connecting means is spaced apart from the continuous event sensitive connecting means by a predetermined distance. It refers to all of the event-sensitive access means.

In FIG. 1, liquid was present at the first point 1, which is a point on the position detecting member, but the position is unknown. As a result of the event, the electrical connection (E) is made between the position detecting member and the power supply member. The power source 15 is connected to one end of the position detecting member, that is, the second point 2 described above, via the connecting means 152. In addition, the power source is connected to the power source member via the auxiliary connecting member 13. As indicated by the plurality of connections 151, the connection between the power source and the power member may be made at one or more points on the power member. Furthermore, as long as the power source can cause a known current to flow between the first and second points of the position detection member, this connection can be any unknown impedance. Therefore, the connection is made at the first point, and thus the connection, the position detecting member between the first point and the second point, the power source 15 and the auxiliary connecting means 13, and a part of the power source member 12 (connection point) A test circuit is formed that includes a single connection 151 between the power supply member and the power supply in the case. As described in detail below, an important advantage can be obtained if the only change in the impedance of the test circuit is the connection impedance between the power supply member and the position detection member. The result can be achieved by using a power supply member having the same impedance characteristics as the position detecting member and an auxiliary member connected to the power supply member only at the end far from the second point 2.

The voltage measuring device is connected to the second point on the position detecting member via the return member 16 and is connected to the position detecting member at one or more points from which the distance from the second point is at least to the first point. As indicated by the number of connections 141, this connection must be of a very small impedance relative to the known impedance or the impedance of the voltage measurement device. Thus, the voltage measuring device constitutes a part of the reference circuit composed of the device 14 and at least part of the position detecting member 11 between the first point and the second point and the return member 16.

The power source 15 and the voltage measuring device 14 may be connected to the second point 2 on the position detecting member 11 as convenient. Thus, as indicated by the plurality of connections 153, the connection member 152 and the return member 16 may be interconnected at one or more locations.

The location of the first point includes (a) the current flowing between the first and second points, (b) the impedance of each element of the reference circuit, (c) the voltage drop measured by the voltage measuring device, and (d) the second point. Knowing the position of the point 2 and (e) the impedance of the position detecting member between the second point 2 and each point on the position detecting member can be calculated. Systems that know these characteristics can be implemented in a number of ways. The accuracy of the position detection at the first point is limited by the ratio of the impedance of the voltage measuring device to the unknown part of the impedance of the other elements of the reference circuit, and in most cases the impedance of the device to the total impedance of the rest of the reference circuit. It is convenient to use elements with high rain ratios. This ratio should therefore be at least 100, preferably at least 1,000 most preferably at least 10,000. For this reason, connections 141 and 153 in FIG. 1 are shown to have low resistance. On the contrary, the connection impedance between the position detecting member and the power supply member and the impedance of other elements of the test circuit do not affect the accuracy of the obtained information, which is an important advantage of the present invention.

The apparatus and method of the present invention can be used to detect and detect the presence of a liquid as well as to provide other information.

The connection E may be of some kind, for example an ionic connection or an inductive connection resulting from the presence of an electronic connection or electrolyte with zero impedance or significant impedance. The change that occurs for connection E is the desired reversible change. However, the present invention can also be used when the change is permanent and requires replacement or repair of the device to restart the system. The system may be arranged to signal only while liquid is present, or may be installed to signal when liquid is present. In the latter case, the system can usually be reinstalled.

Some examples of liquids that can be detected without limitation are:

(A) the presence of water or other electrolytes. In this case, the event sensitive connecting means may be a space only between the position detecting member and the power supply member, or may be a connecting member for collecting or absorbing electrolyte.

(B) A liquid that is non-electrolyte or electrolyte. The electrical connection is a result of the coupling of the liquid and the connection member, for example, may be the result of releasing fluid ionic species in response to a chemical reaction between the liquid and the at least a portion of the connection member. Alternatively, when the liquid augments parts of the conductive polymer connecting member, or the liquid keeps the spring member deformed, or by changing the state of the ionizing box or the transmittance of the photocell, for example in a smoke detector, The presence of the material may cause the shape of at least a portion of the connecting member to change, such as in the case of a solvent for the adhesive or polymer retaining member that causes the position detecting member to connect the returning member.

In some cases it may be desirable to have the system signal the presence of liquid only when the connection between the power supply and the position detection member has an impedance within a predetermined range (i.e., above a certain value, below a certain value, or between two specified values). desirable. For example, when a very small amount of electrolyte results in a very high resistance connection, it is desirable that the system not signal the presence of the liquid. In this case, a system in which the presence of liquid is not signaled when the V / I ratio is outside the predetermined range is preferable, where V is the output voltage (V) of the power supply in the test circuit, and I is the current (A) of the test circuit.

This is especially important when the power supply is a fixed current source. Because the presence of a liquid causing a very high impedance connection, the voltmeter may give a false indication of the location of the event. This is because if the compliance voltage of the power supply is high enough to drive a fixed current in the test circuit, only the fixed current source will give the expected fixed current. Thus, if the impedance of the test circuit is too high, the actual current of the test circuit will be less than the "fixed" current, and the voltage drop between the first and second points of the position detection member will not accurately represent the location of the first point. . If the current is below a fixed value, this problem may be solved by deleting the indication of the voltmeter or including a current switch in the test circuit to prevent current below the "fixed" current from flowing into the test circuit.

Even when the degree given for the presence of the liquid is correct, the transfer of such information may be undesirable. In such a situation, when using a constant current source, the output voltage of the power supply will be controlled, and the output voltage is not within the predetermined range and can prevent the transmission of information. Similarly, when using a constant voltage source, the current in the test circuit can be controlled and the transfer of information can be inhibited if the current is not within the predetermined range (e.g. the use of a current switch or an indication accompanied by a voltmeter or a voltmeter). delete).

In this kind of system, the critical parameter that determines whether information is advancing or not is the impedance of the test circuit, so that the only variable impedance of the test circuit is preferably the impedance of the connection. It is (1) connected in series to the position detecting member between the first and second points, and (2) the difference between the impedance of the position detecting member between the first and second points of the total impedance of the position detecting member and This can be achieved by including elements of the same impedance in the test circuit. The above-mentioned element is preferably given by including in the test circuit a power supply having an impedance characteristic such as the position detecting member and a complement layer portion of the position detecting member. The above can also be done by having the return member form part of the test circuit (FIG. 9) or by including an auxiliary member connected to the end of the power supply member remote from the second point. If such an element is present, the strength of the system will be the same throughout its length. Without this element, the impedance to the position detecting member between the first and second points would also be in one variable state, making it impossible to accurately fix the impedance range of the connection that would signal the event. In the absence of such an element, the limit of the connection impedance shall be at least twice, in particular at least five, and at least ten times the impedance of the entire length of the positioning member.

The sensitivity of such a system can be easily changed (eg, so that different minimum magnitude leaks are signaled). When using a fixed current source, it is possible to change the sensitivity of the system by changing the power supply's compliance voltage and / or by including the perceived impedance in the test circuit and / or by varying the range of pre-selected output voltages. When using a fixed voltage source, it is possible to vary the magnitude of the voltage and / or to include a known impedance in the test circuit and / or to change the preselected current value.

Also included in the invention is a device suitable for connecting the position detecting member, the power supply member and the return member to produce a system in which information is reported only when the V / I value is within a predetermined range.

(1) the first terminal

(2) with the second terminal

(3) with the third terminal

(4) means for connecting the first terminal and the second terminal to a power source;

(5) a voltage measuring device for measuring the voltage drop between the first terminal and the second terminal;

(6) a display device for displaying information derived from the voltage drop measured by the voltage measuring device;

(7) When the first terminal and the second terminal are connected to the power supply, and connected to each other through the position detecting member and the power supply member to form a test circuit, the V / I value (I: current of the test circuit (amperes), V: If the output voltage (volt) of the power supply is out of the predetermined range, the display device is configured to prohibit the information display of the display device. The device also constitutes a support member to which each element of the device is attached and / or a housing for physical and / or electrical protection of each element.

When a fixed current source is used to provide very low current, the current can vary from a fixed value to about 4 percent even when the output voltage is below the compliance voltage. In addition, other factors can cause the current of the test circuit to change over time. Under this situation, the test circuit includes a reference impedance connected in series with the position detecting member, and the position of the first point is calculated from the ratio of the voltage drop between the first point and the second point to the voltage drop of the reference impedance. In practice, this procedure measures the current in the test circuit by measuring the voltage drop across the reference impedance. A more detailed description is given in US Patent 603,484.

The position detecting member is an elongate member, the length of which may be at least 100 times, sometimes 1,000 times or more, and 10,000 or 100,000 times more than other sizes. However, the position detecting member may be plate-shaped or have other complicated shape.

The position detecting member preferably has sufficient impedance to cause a voltage drop that is easily and accurately measured. It is therefore desirable to have a resistance of at least 0.33 ohm / m, in particular at least 3.3 ohm / m, for example 3.3 to 16.5 ohm / m. On the other hand, the resistance should not be too high. 3.3 × 10 ⁴ ohm / m or less, particularly 3.3 × 10 ² ohm / m, of which 65.5 ohm / m or less is preferable. A key feature of the present invention is that under operating conditions the impedance of the position detecting member depends only on the distance between the first point and the second point. Otherwise, the position of the first point cannot be calculated from the change of the voltage measured by the voltage measuring device. Since the locating member has a constant cross-sectional area along its longitudinal direction, the resistance per unit length is also constant, and the voltage change is directly proportional to the distance between the first point and the second point. But this is not essential. Because knowing the change in impedance along the length of the member can correlate the voltage change with the length. Therefore, a considerable advantage can be obtained by using a position detecting member composed of a plurality of constant spacing impedances connected by a low impedance road intermediate member. The most common variable state affecting the resistivity (and therefore the resistance) of the position detecting member is temperature. Many materials, in particular copper and other metals, are not critical for many purposes, but to temperatures that are unacceptable in determining the location of the first point in an unexpectedly changing temperature along the longitudinal direction of the position sensing member. The resistivity changes accordingly.

Therefore, the position detecting member may have an impedance thermometer of at least 0.003, in particular 0.0003, and not more than 0.0003, for a temperature change of at least 25 ° C in the temperature range of -100 ° C to + 500 ° C, especially 0 ° to 100 ° C, in particular 0 ° to 200 ° C. Must have a number For simple metal conductors, the impedance temperature coefficient is equal to the resistivity temperature coefficient. The value for copper is 0.007 / ° C. Metals with low resistivity temperature coefficients are well known and include, for example, Constantan, Manganese and Coppell (see International Critical Tables, 1929, McGraw-Hill Book Co., Vol. VI, Paghes 156). -170).

Of course, the position detecting member, the power supply member and the return member must be assembled with such strength and sufficient strength to withstand the stresses applied to them during installation or use. Normally, this problem does not occur for the return member. This is because it can be firmly embedded in a conventional polymer insulating jacket.

However, electrical contact is required at the intermediate point between the position detection member and the power supply member. This can be a problem when one or more members are wires of relatively small cross section. However, in various applications of the present invention, particularly when the liquid is an electrolyte, a good combination of properties required by the use of a position detecting member and / or a source member electrically surrounding the metal core and the metal core and composed of a long jacket of conductive polymer It turns out that you can. "Electrically encircle" means here that all the electrical path of the core passes through the jacket. Typically the conductive polymer will completely surround the core using, for example, melt extrusion. However, jackets provided with repeated insulation and conduction may be used.

"Conductive polymer" herein refers to a polymer component (e.g. thermoplastic or elastomer or a mixture of two or more of these polymers) and a special conductive filler (e.g. carbon black, graphite: metal powder or the like) dispersed in the polymer component. Or two or more of them). (Refer to the conductive polymer: US Patent Nos. 2, 952, 761, 2, 978, 665, 3, 243, 753, 3 , 351, 882, 3, 571, 777, 3, 757, 086, 3, 793, 716, 3, 823, 217, 3, 858, 144, 3, 861 , 029, 4, 017, 715, 4, 072,848, 4, 117, 312, 4, 177, 446, 4, 188, 276, 4, 237, 441, 4, 242, 573, 4, 246, 468, 4, 250, 400, 4, 255, 698, 4, 271, 350, 4, 272, 471, 4 , 304, 987, 4, 309, 596, 4, 309, 597, 4, 314, 230, 4, 315, 237, 4, 317, 627, 4, 318, 881 and 4, 330, 704; J. Applied Polymer Science 19 813-815 (1975) .Klason and Kubat; Polymer Engineering and Science 18, 649-653 91978 ), Narkis et al; German OLS 2, 634, 999; 2, 755, 077; 2, 746, 602; 2, 755, 076; 2, 821. 799; European Application No. 38, 718, 38, 713, 38, 714, 38, 716; U. K, Application No. 2, 076, 106A; the application correspending to U.S. Serial Nos. 184, 647 (Lutz), 250, 491 (Jacobs stal), 273, 525 (Walty), 274, 010 (Walty et al), 272, 854 (Stewart et al), 300, 709 (Van Konynenburg et al), 369, 309 (Widgley et al), and 380400 (Kamath).

Typically, the resistivity of the conductive polymer varies with temperature at a ratio above the coefficient of temperature set above, and the PCT conductive polymer sometimes increases its resistivity by 10 times or more over the temperature range of 100 ° C. Therefore, in the position detecting member constituting the conductive polymer jacket, the conductive polymer jacket in all temperature ranges, for example, 0 ° to 100 ° C, is at least 10 times, preferably at least 1,000 times, for the core of each longitudinal section. It is important to have resistance. Since the core and the jacket are connected in parallel in this way, the jacket makes no contribution to the resistance of the long conductor, and the change of resistance with temperature is not important.

The second point in the position detection member must be known in position and is usually a fixed point. When the system is designed to detect different kinds of events that occur dependently, it is desirable to make the second point the same fixed point for the detection of other events. In the case of an elongate position detecting member, one end or the other end of the position detecting member is the second point. However, the present invention uses multiple second points, for example, simultaneously or sequentially to determine the location of multiple first points when multiple different events have identified multiple first points.

The power supply member generally has the same general characteristics as the position detection member. Occasionally, as described in section 10 below, the power source member may be the same as the position detecting member.

The return member is conveniently low insulated wire that is low enough that the resistance per single length can be neglected to obtain information about the event, for example, less than 0.01 times the resistance per unit length of the position detection member.

The power supply member, the position detection member, the return member, the auxiliary member and other long members required (e.g. to impart continuity or physical strength of the inspection) may be combined with each other in a convenient way to create a sensor cable installed along the long path. Can be. If necessary, the ear member or position detecting member or other member may be made of a relatively large and strong member, and thus the other member may be fixed in the form of a strap, for example, a wrap, which may include an additional long member. We can do with strong member that there is. Details of the various packaging structures are described in US patent applications 556, 740 and 556, 829.

A very valuable improvement can be achieved by using a position sensing member which has an impedance which may be the connection variable due to the presence of the liquid in the test circuit, or may be so. As described above, a system can be designed that only responds to events that cause a connection whose impedance is within a predetermined range at all points along the length. Another important advantage is the ability to measure the impedance of the connection itself. For example, (a) measuring the output voltage when a constant current source is used, (b) measuring the current in the test circuit when a constant voltage source is used, or (c) after the location of the event is determined, the voltage measured by the voltmeter The above advantages can be obtained by including the switch system to form a new circuit which is an impedance measure of the event.

The current traveling between the first and second points should be of a known magnitude, preferably supplied by a control current source, for example galvanostat. However, if the device includes a current measurement device, the first point can be calculated using the control voltage source. The current may be continuous or pulsed direct current or regular sinusoidal or other forms of alternating current. The current flowing between the first and second points is in the range of 0.05 to 100 milliamps, in particular in the range of 0.1 to 10 milliamps, for example in the range of 0.5 to 3 milliamps. However, when very long paths are monitored for an event, even lower currents can be used, especially when using a reference impedance. The control current source is preferably a fixed current source or current source that can be adjusted to provide the required and known value of current, for example to improve the accuracy of the liquid detection detected at low current levels. However, it is also possible to use a fixed voltage source with a current measuring device for measuring the current flowing between the first and second points. The power source is always connected to the second point of the position detection member, preferably insulated from the position detection member in the absence of an event.

The voltage measuring device may be of any kind and is well known to those skilled in the art. The voltmeter is preferably a voltmeter having a resistance of at least 10,000 ohms, preferably at least 1 megohms, in particular at least 10 megohms.

As briefly pointed out in the description of FIG. 1, the physical and electrical relationships between the elements in the device of the present invention may vary widely. 2-24 are a number of other preferred embodiments. In each of the 2-24, a power source 15, a voltage measuring device 14, a position detecting member 11, a power source member 12, and a return member 16 are shown.

The position detecting member is shown as one resistor because the power supply member must bear a detectable resistance for sufficient voltage drop to enable accurate position tracking of the point 1 connected to the position detecting member. In some figures the power supply element is shown as a simple low resistance conductor and in other figures is shown the same resistance member as the position detection member. The return member is preferably a simple low resistance conductor but if it is a known resistance the return member may have significant resistance. Connections E, E ₂ , E ₂ , E ₃ allow these connections of the present invention to be medium and high resistance if they form part of the test circuit (of course they are zero resistance or substantial real and known resistance) It is shown as resistance). On the other hand, if these connections form part of the reference circuit, the present invention is shown as a simple conductor since these connections require a known, preferably small resistance. In many figures the switches S, S ₁ , S ₂ are shown. In addition to a simple switch that produces a zero-resistance electrical contact in the test circuit, any other means may be used, and any other means of imparting a connection of known resistance may be used in the reference circuit. In FIG. 2 to FIG. 29, a power source is shown as a control current source in most of the drawings, but in FIG. 3 and FIG. 26, the power source is a storage battery, and the test circuit includes an ammeter 154. In FIG. It is a control voltage exchange source and the test circuit includes an ammeter 154.

Referring to FIG. 2 to FIG. 29, various preferred examples of the present invention are described as follows.

(A) As shown in FIGS. 2-7 and 12-29, the power source may be located near the second point of the position detecting member, and as shown in FIGS. 8-9, the position far from the second point is detected. It may be located near the end of the member. In most cases, the power supply voltage measuring devices are located close to each other, as shown in FIGS. 2-5 and 7-9.

(B) For example, as shown in FIG. 10, the connection between the position detecting member and the power supply is made so that the second point is opposite the position detecting member from the first arrangement (FIG. 2) at the foot end of the position detecting member. First, measure the distance from one end of the event, as the device includes a limit or more switches that can be paired with each other or operate independently of each other to move to the second array at the end (Figure 9). Then, the distance from the other end where the event occurred can be measured.

(C) Also as in FIGS. 5, 7, 19, and 20, the apparatus may cause a connection between the generator power source member and the position detection member as well as the connection between the return member and the position detection member. It may be. Such a device may be valuable, for example, to impart a device that is cut to a predetermined length. The connection between the position detecting member and the returning member may be an integral result of the connection between the position detecting member and the power supply member by, for example, a double switch, and a state in which one connection is made may cause another connection. These two possibilities are shown in FIG. Alternatively, the connection between the position detecting member and the return member may be due to the existence of a state different from the state causing the connection between the position detecting member and the power supply member. This possibility is illustrated in FIGS. 7, 19 and 20.

(D) also by including one or more switches in the apparatus that are coupled to each other or operate independently as in the example shown in FIG. 11, as shown in FIG.

(a) A current is driven along the entire length of the position detecting member by the power supply,

(b) the return member is electrically connected to the second point on the position detecting member via a voltage measuring device, or is insulated from the position detecting member,

(c) When the presence of the second and other types of liquid occurs, a known impedance connection occurs between the position detecting member and the returning member, thereby between the first and second points in the voltage measuring device and the position detecting member and the returning member. A reference circuit consisting of a portion placed at the base and an impedance of the base is formed, and the voltage measuring device can convert the apparatus into an electrical system having a very high known impedance compared to the unknown portion of the impedance of other elements of the reference circuit.

(E) Also, as shown in FIG. 13, when liquid detection is required only in an area spaced apart by a certain distance, the position detecting member gives (a) a series of points at which a connection can be made, and is preferably relatively per unit length. A large number of long distance sensing elements (114A, 114B, 114C and 114D in FIG. 13) with high resistance and (b) physically separating the position detecting elements and electrically connecting the position detecting elements, and directly It is also possible to construct a number of long intermediate elements spaced at regular intervals that cannot be connected to the power member. The system can be used, for example, when stop and position detection is required in each interior (but not between housings) of a plurality of housings separated from each other along a distance.

(F) Also, as shown in FIG. 14, the method of the present invention can also be used when detecting the location of an event along a branched path. However, when the branched system is used as described above, it may be possible to detect the position of two or more liquids if the voltage measuring device indicates the presence of the liquid at a certain distance beyond the first point. If necessary, the control current source and the voltmeter can be connected to the conductor at the branch point (preferably via a low-resistance drop wire installed at the same time as the detection system) to determine its position (usually the preposition after the adjacency of the event is indicated). In order to be more accurate, the above measures can be used in non-branching systems). Alternatively, only one branch at a time can be tested by using different frequency AC current sources sequentially and replacing the filter instead of another branch.

(G) Also, as shown in FIGS. 9 and 15-18, the power supply member may have the same impedance characteristics as the position detection member, and may be connected such that the only variable impedance of the test circuit is the connection impedance. The position detecting member and the power supply member are shown as a continuous resistor having a constant resistance per unit length. Connection E is shown as a medium size resistor.

FIG. 17 is the same as FIG. 15 except that a second voltmeter 19 for measuring the output voltage of the power source may be included. As long as the power supply provides the required "fixed" current, the impedance of the connection E can be calculated from the output voltage.

18 is similar to FIG. 15 and includes a switch 9191 such that the return member is connected as shown or separated from the end of the position detection member and connected to the end of the power supply member. In the latter case the voltage measured by the voltmeter is a measure of the impedance of connection E.

The relationship between the voltage drop measured by the voltage measuring device and the distance between the first point and the second point depends on how the device is designed. If a connection can be made to the position detecting member at any point along its length, and if the impedance along the position detecting member is uniform, then the relationship will be a straight line with a constant slope as shown in FIG. Since the event sensitive connection means is discontinuous, if the connection to the position detecting member is possible only at a certain distance apart, the relationship will be a series of points as shown in FIG. If the position detecting member is separated into the position detecting portion and the connecting portion as shown in FIG. 13, and the position detecting member can contact any point inside the position detecting portion, the relationship is as shown in FIG.

22 and 23 show cross sections for the device of the present invention. In FIG. 22 and FIG. 23, the device is a power source member having a metal core 121 and a conductive polymer coating 122, a core 111 and a conductive polymer coating 112 made of a metal whose resistivity does not change with temperature. The return member 16 is composed of a detection member and a metal and is surrounded by a polymer insulating jacket 161.

In FIG. 22, the polymer insulated connecting member 20 having a concave surface lies between the power supply member and the position detecting member, and the elements are connected together by an insulating jacket 91 through which an opening can be formed to penetrate the liquid. have. If there is no electrolyte around the device shown in FIG. 22, no electrical connection occurs between the position detecting member and the power supply member. However, the device is exposed to the electrolyte and an ionic connection occurs between the position detecting member and the power supply member.

In FIG. 23, the member 21 is between the position detecting member and the power supply member, the element is surrounded by an insulating jacket 92, and under normal conditions, the member 21 prevents electrical contact between the position detecting member and the power supply member. However, member 21 consists of or comprises a material that becomes an electrical conductor when an event occurs. For example, the presence of chemicals in which the event delivers excessive pressure through the flexible jacket 92, or includes an excess temperature at which the event can melt bubbles, or penetrates the jacket 92 and reacts with the foam member. It is possible to constitute the member 21 with an organic polymer bubble containing a material that forms a toxic ionic species when the bubble structure is impaired. In addition, the member 21 may be configured as a material that becomes conductive when compressed.

The present invention will be illustrated by the following example.

Example 1

A circuit as shown in FIG. 2 was prepared. The control current source is galvanostart with an ohm compliance voltage of 18 volts, generating a control current of 0.001 amps. The voltmeter has an input impedance of 1 megohm and the total scale is up to 200 mV. The power supply member is a 30AWG copper wire (about 0.032 cm in diameter) and is surrounded by a melt-extruded conductive polymer jacket. The jacket was about 0.04 inches thick. The conductive polymer composition has a resistivity of about 3 ohm cm at 25 ° C. and consists of carbon black dispersed in a thermoplastic rubber presumed to be a mixture of polypropylene and ethylene / propylene rubber (about 55 parts by weight) (trade name TPR-5490). will be. The position detecting member is the same as the first one except that 30AWG constantan wire (diameter about 0.032cm) is used instead of copper wire. The resistance of the second conductor was 9.65 ohm / m. The return member is a 12 AWG copper wire (approximately 0,28 cm in diameter) and is surrounded by a polymer insulating jacket.

In various tests, a braking sponge was installed in the position detecting member and the power supply member to make an electrical connection therebetween, and the members were dried between tests. As theoretically estimated, the distance to the braking sponge (d: m) can be calculated by

Here, V is the voltage V recorded in the voltmeter.

The difference between the actual value and the calculated value for the d value was less than 0.1%.

Example 2

A circuit as shown in FIG. 2 was prepared, and the galvanostart and the voltmeter as in Example 1 were used. The operation of the device is a gus similar to that shown in FIGS. 37 and 38, as follows. In order to prepare the power supply member, strip-shaped copper foil was attached to the inner bottom surface of the cross-linked polyvinylidene fluoride tube. In order to prepare the position detecting member, a 30 AWG constant carbon wire is fixed in the polyvinylidene carbide tube on the radially opposite side of the copper strip, that is, the inner upper surface, and the wire is applied to the tube at regular intervals so that the tube is extended over its length. Contact with is maintained. The return member was a 30 AWG insulated copper wire (diameter about 0.032 cm).

In various tests, pressure was applied to the upper surface of the tube at a position separated at the end. When the tube was elastically deformed, the position detecting member was contacted with the power supply member and the position of the pressure point could be calculated from the value indicated on the voltmeter.

Claims (8)

Apparatus for detecting and detecting the presence of liquid at a first point (1) along a long path, the device comprising (A) one sensor cable, which goes along the long path and comprises That is, (1) the long detection member (11). (i) the detection member comprises a metal core 111 and an elongated jacket 112, the jacket electrically surrounding the core 111, the jacket comprising a conductive polymer, and (ii) the detection The impedance from one end of the second point 2 to the first point 1 of the member defines the position of the first point, and (2) as a long power source member, which is spaced apart from the detection member and has a metal core And a long jacket 112, the jacket electrically enclosing the core 121 and made of a conductive polymer, (3) a liquid sensing connection means, wherein the means comprises a detection member 11 and a source member. (B) Voltage measuring device 14, which affects the electrical connection E between the detection member 11 and the source member 12 of the first point 1, with the liquid interposed and detected. The apparatus 14 determines the voltage drop between the first low point 1 and the second point 2, and (C) has a power source 15, The circle is electrically connected to the second point 2 at the detection member when the liquid is present at the first point 1, and (D) is provided with a return member 16, which is a part of the sensor cable. And (i) a first end which is electrically connected to the second point 2 at one end of the detection member 11 via a voltage-measuring device 14 and an electrical connection to an opposite end of the detection member 11 ( ii) having a second end, wherein the return member 16 is otherwise insulated from the detection member 11, wherein an electrical connection between the detection member 11 and the power supply member 12 is due to the presence of the liquid. Affecting E), this results in (a) molding a detection circuit, which comprises: (i) a connection between the detection member between (E) and (ii) the first point (1) and the second point (2); (iii) a power source, said power source causing a current of known magnitude to be transmitted between the first point (1) and the second point (2), and (b) forming a reference circuit, the circuit comprising Voltage measuring device (14), gum Member 1 and voltage measuring device 14, detecting member 1, and returning member 16, the voltage measuring device 14 having a very high impedance compared to the impedance of other components of the reference circuit. A device for detecting and detecting the presence of a liquid. 2. Apparatus according to claim 1, wherein the power source is a controlled current source which supplies a known fixed current when the connection (E) is made. The device of claim 2, wherein the known fixed current is 10 milliamperes or less. 2. The apparatus of claim 1, further comprising: (E) means for displaying information about the position of the liquid when the value of the V / I ratio is within a predetermined range, where V is the output voltage of the power and I is the test circuit. (F) a device for detecting and detecting the presence of a liquid, characterized in that it is ampere as a current, and (F) means for preventing the display of information about the position of the liquid when the value of the V / I ratio is outside the selected range. . The liquid according to any one of claims 1 to 4, wherein the liquid-sensing connection means is an air gap, thereby making a connection having a practical and unknown impedance in the presence of a liquid electrolyte. A device for detecting and detecting the presence of a. The method according to any one of claims 1 to 4, wherein (a) the position detecting member 11 has a total impedance Ztota1, and (b) the inspection circuit comprises one component, the component comprising: i) a first Connected in series with a part of the position detecting member between the point 1 and the second point 2, and ii) has an impedance (Ztotal-Zpart), where Zpart is the first point (1) and the second point ( 2) an apparatus for detecting and detecting the presence of a liquid, characterized in that it is the impedance of the position detecting member. 5. Device according to any one of the preceding claims, characterized in that the position detecting member (11) has substantially the same impedance characteristics as the source member (12). The method according to any one of claims 1 to 4, wherein the reference impedance connected in series with the position detecting member is for comparing (i) the voltage drop between the first and second points and (ii) the voltage drop on the reference impedance. And means for detecting and detecting the presence of a liquid.

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