JPH02287143A - Liquid detecting element - Google Patents

Abstract

PURPOSE:To surely distinguish an acidic or alkaline liq. from rainwater, etc., with a simple structure by covering the conductor of the element with a coat to be dissolved only when brougth into contact with an acidic or alkaline liq. CONSTITUTION:Two conductors 2 and 2 are arranged on the upper surface of an insulating substrate 1 in parallel away from each other, the coat 3 is placed thereon and welded to the substrate, and the conductors 2 and 2 are sandwiched between the substrate 1 and the coat 3. When the structure is used as an acid detecting element, the coat 3 is made from an alkaline polymer such as polyvinyl pyridine and a polyamide copolymer, and the coat 3 is made from an acidic polymer such as a PVA-based resin when the structure is used as an alkali detecting element. The liq. detecting element S1 of such structure is indifferent to rainwater, etc. The coat is dissolved when the element is brought into contact with an acidic or alkaline soln., and the electrical characteristic between both conductors is changed due to the presence of the soln. between the conductors. Accordingly, the liq. can be surely detected by measuring the change.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a liquid detection element that detects the arrival of an acid or alkaline solution.

[Prior Art] Conventionally, as a liquid detection element, those described in Japanese Patent Publication No. 57-5002, Japanese Utility Model Application Publication No. 58-96248, etc. are known. These two are arranged parallel to each other.
By keeping individual conductors insulated from each other with an insulator and measuring changes in electrical characteristics such as resistance and impedance between the conductors caused by liquid intrusion, it is possible to determine whether liquid leaks or not. It was used to detect the arrival of the enemy.

[Problems to be Solved by the Invention] By the way, although conventional methods can be applied to detect many types of liquids, regardless of whether they are acids or alkaline solutions, on the other hand, they also detect rainwater etc. in the same way. Without rigorous data analysis, it was not possible to determine whether the leak was from an actual pipeline or just rainwater. Therefore, it has been difficult to accurately monitor only acid or alkaline solutions using simple equipment.

[Means for Solving the Problems] In order to solve the above problems, the liquid sensing element of the present invention includes two conductors arranged parallel to each other and an insulator that insulates them from each other. The invention is characterized in that a covering is provided to cover at least one of the conductors from the outside world, and the covering is made of a substance that dissolves only when it comes into contact with an acid or alkaline solution. In this case, the covering may be provided so as to directly cover the conductor, or may be provided so as to cover the insulator as well.

[Function] Even if rainwater or the like comes into contact with the detection element, the conductor remains covered with the covering, so no change occurs in the electrical characteristics between the conductors. On the other hand, when an acid or alkaline solution comes into contact with the element, the coating dissolves and the presence of the solution between the conductors causes a change in the electrical characteristics between the two conductors. Therefore, by measuring this change, it is possible to detect the arrival of an acid or alkaline solution.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a cross section of the liquid sensing element S1 of the first embodiment. In the element S1 of this embodiment, two conductors 2.2 are arranged in parallel with each other on the upper surface of an insulating substrate 1, and a cover 3 is placed and welded on top of the two conductors 2.2. , it has a structure in which it is sandwiched between an insulating substrate 1 and a cover 3.

When used as an acid detection element, the covering 3 is made of an alkaline polymer, such as polyvinylpyridine or polyamide copolymer. In addition, in the case of using an element for alkaline detection, the covering body 3 is made of an acidic polymer, for example, a polyvinyl alcohol-based resin. This point also applies to the following examples.

Next, explaining another embodiment, the liquid sensing element S2 of the second embodiment shown in FIG. They are arranged in parallel and have a structure in which the outer periphery of an insulator 11 is covered with a covering 13. In addition, in the case of this element S2, it may be in the form of a twisted wire.

The liquid detection element S3 of the third embodiment shown in FIG. It has a structure in which an outer conductor 23 having a magnetic conductor is provided, and the outer periphery of the outer conductor 23 is covered with a covering member 24.

The liquid detection elements s1%S2 and S3 of each of the above embodiments each have a coating 3.13.24 that dissolves only when it comes into contact with an acid or alkaline solution, so they do not detect rainwater etc. Or only alkaline liquids are detected. Therefore, it can be distinguished from rainwater, etc., without a strict analysis.

[Effects of the Invention] As explained above, the liquid sensing element of the present invention has a conductor that
Since it is covered with a coating that dissolves only when it comes into contact with acid or alkaline liquid, it is not detected even if rainwater comes into contact with it, and only acid or alkaline liquid can be detected. Therefore, even with simple detection equipment, it is possible to reliably detect acidic or alkaline liquid, distinguishing it from rainwater or the like.

[Brief explanation of drawings]

1, 2, and 3 are the first and second embodiments of the present invention, respectively.
, is a sectional view of the third embodiment. 1...Insulating substrate, 11.22...Insulator, 2゜12...Conductor, 21...Center conductor, 23... Outer conductor, 3.13.24...
...Covering body. 1st! ! 1 Figure 2 3tm

Claims (1)

[Claims] In a liquid sensing element comprising two conductors arranged parallel to each other and an insulator that insulates them from each other, a covering is provided to cover at least one of the conductors from the outside world, and this covering is coated with an acid or A liquid detection element characterized in that it is composed of a substance that dissolves only when it comes into contact with an alkaline solution.