JPH0554905B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gas detection sensor with increased detection probability, which is suitable for use in gas leak detectors and the like.

[Conventional technology]

Conventional gas detection elements are, for example, disclosed in Japanese Patent Application Laid-open No. 1983-
Since solid electrolytes or metal oxides as described in Publication No. 118661 are used, they are not only relatively expensive, but also point-like, so even if the gas to be detected passes near them, There was a drawback that the gas could not be detected unless it reached the point-shaped detection element.

Therefore, when it comes to detecting gas leakage into the atmosphere, the probability of detection is extremely low unless a considerable amount of effort is made in the installation location, etc.

[Problem that the invention seeks to solve]

Therefore, this invention eliminates the above-mentioned conventional drawbacks,
It is an object of the present invention to provide an economically obtainable gas detection sensor with increased gas detection probability.
That is, the conventional dot-like sensing elements are made to be continuous with linear sensing elements, and are also meandered to form conductive paths arranged in a planar manner.

[Means for solving problems]

Therefore, according to the present invention, there is provided a gas permeable conductor made of a synthetic resin filled with a conductive material, which forms a conductive path arranged in a planar manner by continuous and meandering, and a A gas detection sensor includes lead wires electrically connected to each other, and a gas permeable film made of a continuous porous film that covers at least the conductor.

In this configuration, as a gas permeable conductor,
If a stretched porous tetrafluoroethylene resin filled with a conductive material is used, and a continuous porosity stretched porous tetrafluoroethylene resin film is used as the gas permeable film, it will not only be highly corrosion resistant and weather resistant, but also water repellent. This is advantageous because it can provide a sensor that has a long life and does not malfunction due to water or the like.

[Effect]

A gas-permeable conductor has continuous and meandering linear sensing elements to form a conductive path arranged in a planar manner, so even if gas is detected at one point on this conductive path, the series combined impedance will not change. can be detected as As a result, the detection area of this gas detection sensor is greatly expanded, and when gas arrives at any point on the gas-permeable conductor, that is, the detection part, it can be detected immediately.
Gas detection probability increases significantly.

When gas arrives at a gas-permeable conductor, if the gas is an insulating gas, it will be detected as an increase in the series composite impedance, and if it is a conductive gas such as an ionized gas, it will be detected as a decrease in the series composite impedance. can.

If tetrafluoroethylene resin is used for the structural members, it has high corrosion resistance and can be used to detect corrosive gases. In addition, if stretched porous ethylene tetrafluoride resin is used as the gas permeable film, it will have excellent water repellency.
Malfunctions caused by the arrival of liquids such as water are eliminated.

〔Example〕

FIG. 1 is a plan view of a gas detection sensor 1 according to an embodiment of the present invention.

In the figure, a tape-shaped gas permeable conductor 2
The outer periphery is a gas permeable film 3 made of a stretched porous polytetrafluoroethylene resin film with continuous pores.
covered by. This gas permeable conductor 2
As shown in FIG. 2, four of them are arranged side by side on the substrate 4, and their ends are electrically connected in series by a conductive connection piece 5. Both ends of the gas-permeable conductor 2 forming a continuous conductive path through the series connection thus obtained are electrically connected to a lead wire 7 via a conductive connection piece 6 . A connector 8 is attached to the tip of this lead wire 7. The connection portions of the conductive connection pieces 5 and 6 and the lead wire 7 are covered by a support plate 9.

When gas arrives at the gas detection sensor 1 having a planar structure as shown in the figure and reaches the inside of the gas permeable conductor 2,
The impedance of the part changes and its value becomes
It is detected by a detector (not shown) connected via a lead wire 7 and a connector 8.

In particular, when the gas arrives at multiple points on the gas-permeable conductor 2, it causes a large change in the series combined impedance.

Here, the gas-permeable conductor 2 is, for example, a tape obtained by adding an auxiliary agent to a tetrafluoroethylene resin mixed with 20% by weight of carbon and extruding it by a ram, and stretching the tape to a thickness of 0.11 mm.

Next, FIG. 3 shows a plan view of another embodiment of the gas detection sensor 10 according to the present invention.

In the case of the gas detection sensor 10 according to this embodiment,
A tape-shaped gas permeable conductor 12 is placed on the substrate 11.
is bent to form a continuous conductive path arranged in a W-shape, and lead wires 14 are conductively connected to both ends of the conductive path via conductive connection pieces 13. The connecting portion and the gas permeable conductor 12 are covered with a gas permeable film 15 made of a continuous porous membrane such as a stretched porous tetrafluoroethylene resin film. Note that 16 is a connector.

The gas detection sensor 10 according to this embodiment also has a first
The same effects as the gas detection sensor 1 according to the illustrated embodiment can be obtained.

Note that this invention is not limited to the above-mentioned embodiments, and can be modified within the scope of the idea of this invention, for example, by providing unevenness on the gas-permeable conductor to make it easier to trap gas. be.

〔Effect of the invention〕

As described above, according to the present invention, there is provided a gas-permeable conductor made of a synthetic resin filled with a conductive member, which is continuous and meandering to form a conductive path arranged in a planar manner, and both ends of the conductor. By configuring a gas detection sensor including lead wires conductively connected to each of the gas permeable conductors, that is, a gas permeable film made of a continuous porous membrane that covers at least the conductor, any of the gas permeable conductors, that is, the detection portion When gas arrives at a point, it can be immediately detected as a change in the series-connected combined impedance, resulting in a gas detection sensor that significantly improves the detection probability, or detection accuracy, compared to conventional point-shaped detection elements. Therefore, the effect is great.

Furthermore, if tetrafluoroethylene resin is used in each part of the component, it is possible to detect corrosive gases, and if a water repellent such as a continuous pore stretched porous tetrafluoroethylene resin film is used as a gas permeable film, it is possible to detect corrosive gases. This also has the effect of preventing malfunctions due to water splashing, etc.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a gas detection sensor according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line A--A in FIG. 1, and FIG. 3 is a plan view of a gas detection sensor according to another embodiment of the invention. FIG. 1, 10... Gas detection sensor, 2, 12... Gas permeable conductor, 3, 15... Gas permeable film, 7, 14... Lead wire.

Claims (1)

[Scope of Claims] 1. A gas-permeable conductor made of a synthetic resin filled with a conductive material and forming a conductive path arranged in a planar manner by continuous and meandering; A gas detection sensor comprising a lead wire that is conductively connected and a gas permeable film made of a continuous porous film that covers at least the conductor. 2. The gas detection sensor according to claim 1, wherein the gas permeable conductor is made of expanded porous tetrafluoroethylene resin filled with a conductive member. 3. The gas detection sensor according to claim 1 or 2, wherein the gas permeable film is made of a stretched porous tetrafluoroethylene resin with continuous pores.