JPH11125625A - Dissolved gas indicator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily detect a concentration of a gas in a liquid, by setting at a gas introduction opening of a case storing a reagent detecting the gas concentration a functional membrane shutting the introduction opening and passing only the gas. SOLUTION: A dissolved gas indicator 10 has a gas concentration display means 30 inside a case 20 provided with a gas introduction opening 22. The display means displays a concentration of ozone gas introduced in the case 20 by a color change. Moreover, the gas introduction opening 22 is shut by a functional membrane 40 passing only the ozone gas. When the dissolved gas indicator 10 is sunk in water for a predetermined time, the ozone gas penetrates the functional membrane 40 because of a concentration gradient, is introduced into the case 20 and diffused at a gas diffusion layer 32, thereby being uniformly dispersed in the case 20. The ozone gas in the gas diffusion layer 32 reacts with a reagent 36 of a reagent layer 34 sequentially from one close to the gas introduction opening 22 and consequently the reagent layer 34 is gradually decolored. An area of a decolored region corresponds to a CT value of the ozone gas, thus enabling easy detection of a concentration of the ozone gas from a scale.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dissolved gas indicator for detecting the concentration of a gas dissolved in a liquid.

[0002]

2. Description of the Related Art Generally, as a method of detecting the amount of gas (gas concentration) such as ozone gas dissolved in water, a specified amount of a liquid sample in which a gas is dissolved is taken out, mixed with a chemical, and reacted. There is known a method of determining the gas concentration in accordance with the condition.

Another method is to gasify a liquid sample with a gas separation device to separate gas from the liquid,
A method of measuring the concentration of the separated gas using a gas analysis instrument is known.

[0004]

However, the method of mixing and reacting with a chemical is laborious and requires skill, and the method using a gas analyzer is
It requires complicated devices and equipment, and its operation is complicated.

Accordingly, an object of the present invention is to provide a dissolved gas indicator capable of easily detecting the gas concentration in a liquid.

[0006]

According to a first aspect of the present invention, there is provided a dissolved gas indicator for detecting a concentration of a gas dissolved in a liquid, wherein an indicator for detecting the gas concentration is provided. The gas inlet of the case is provided with a functional film that blocks the inlet and allows only gas to pass therethrough.

According to a second aspect of the present invention, in the case, a gas diffusion layer for diffusing the gas introduced from the functional film into the case, and reacts with the gas to change its color according to the gas concentration. An indicator layer is provided.

According to a third aspect of the present invention, the case is filled with an indicator liquid that changes color in accordance with the concentration of the gas introduced from the functional film.

According to the above configuration, when the dissolved gas indicator is submerged in the liquid to be inspected, the gas permeates through the functional membrane and is introduced into the case, and the introduced gas reacts with the indicator in the case. Discolors. This allows the worker
The gas concentration in the liquid can be detected from the discoloration of the indicator after the reaction.

[0010]

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In this embodiment, an example will be described in which the concentration of ozone gas dissolved in water is detected.

FIG. 1 is a side sectional view of a dissolved gas indicator according to the present invention.

As shown in FIG. 1, a dissolved gas indicator 10 displays the concentration of ozone gas introduced into the case 20 by discoloration in a case 20 having a gas inlet 22 for introducing ozone gas therein. Gas concentration display means 30 is provided.
Is mainly covered with a functional film 40 that transmits only ozone gas.

The case 20 has a window for observing discoloration of the gas concentration display means 30 provided from the outside to the inside, and is formed of a transparent material so as to integrally form the window. . The outer shape of the case 20 is formed to have a gas inlet 22 and a depth enough to introduce ozone gas into the inside, and is formed in a rectangular parallelepiped bottomed cylindrical shape.

The gas concentration display means 30 provided in the case 20 includes a gas diffusion layer 32 for diffusing the ozone gas introduced into the case 20, and an indicator layer which changes color according to the concentration of the ozone gas. And a scale for determining the gas concentration from the discoloration of the indicator layer.

More specifically, the indicator layer 34 comprises:

[0017]

Embedded image

The fiber sheet contains an indicator 36 made of an indigo dye having a group, and has a predetermined width and length. Then, the indicator layer 34 is arranged such that the length direction thereof is along the
It is attached to 4.

The scale is formed along the length direction of the indicator layer 34 and corresponding to the CT value (time integrated value of the concentration) of the ozone gas.

The gas diffusion layer 32 is provided adjacent to the indicator layer 34 and is formed as a space.

The functional film 40 provided so as to cover the gas inlet 22 is formed of a film having a large number of fine holes, and is, for example, Gore-Tex.

Next, the operation will be described.

When the dissolved gas indicator 10 is submerged in water for a predetermined time, ozone gas is introduced into the case 20 through the functional membrane 40 due to the concentration gradient, and diffused in the gas diffusion layer 32 into the case 20. Disperse evenly. With this gas diffusion layer 32, a highly sensitive indicator showing a faster reaction can be realized. In addition, the gas diffusion layer 32
The ozone gas reacts with the indicator 36 of the indicator layer 34 in order from the side closer to the gas inlet 22, and the indicator layer 34 is gradually decolorized. The area of this discoloration area is the amount of C
The size is determined according to the T value, and the operator can detect the ozone gas concentration from the scale.

As described above, according to the present invention, since the concentration of ozone gas in the liquid sample to be inspected can be detected by reading the scale, no skill is required in the inspection.
Further, since a complicated electric device is not required, the concentration of the dissolved gas in the liquid can be easily and inexpensively detected.

Next, another embodiment of the present invention will be described with reference to FIG.

The dissolved gas indicator 50 shown in FIG.
As the gas concentration display means 60, an indicator liquid 62 in which an indicator 64 that reacts with the gas to be detected is dissolved is used.

The dissolved gas indicator 50 is
It can be easily manufactured simply by injecting the indicator solution 62 into the inside, closing it with the functional film 40 and enclosing it.

The detection of the ozone gas concentration by the dissolved gas indicator 50 can be easily performed only by comparing the color of the indicator liquid 62 after the reaction with a color sample in which a color corresponding to the ozone gas concentration is displayed in advance. Further, when the indicator liquid 62 is used, the functional film 40 can be used as a film in which the liquid enters and exits unless the components of the indicator 64 flow out.

As a modification of the above-described embodiment, as shown in FIG. 3, seven kinds of indicator liquids having different concentrations of reacting gas are placed in a case 21 in which a case 20 is formed in a square dish shape. Cells 62a, 62b, 62c, 62d, 62
e, 62f, and 62g are partitioned and arranged.
2 may be covered with a functional film 41. When an indicator sheet is used, similarly, seven types of indicator sheets having different reacting gas concentrations are sectioned and arranged at the bottom of a square dish-shaped case, and these indicator sheets are functional membranes. 41.

As described above, the gas concentration display means 30, 60
By using a plurality of indicator sheets and indicator liquid cells, the exposure time to the gas is shortened, and the gas concentration can be easily detected by judging which indicator sheet or indicator liquid cell has changed color.

Next, as another embodiment, a chemical formula of a dye used as an indicator when detecting a gas other than ozone gas and a change in color of the indicator will be described below.

(1) Gas containing acrylonitrile

[0033]

CH ₂ = CHCN + Cr ⁶⁺ + H ₂ SO ₄ → Cr ³⁺ orange → black green (chromium oxide is reduced) (2) Acetylene

[0034]

Embedded image

Light yellow → brown blue (molybdate is reduced to produce molybdenum blue) (3) Gas containing acetone

[0036]

Embedded image CH ₃ COCH ₃ + Cr ⁶⁺ → Cr ³⁺ orange → dark brown (chromium oxide is reduced) (4) Sulfurous acid gas

[0037]

^{Embedded image} SO ₂ + Cr ⁶⁺ + H ₂ SO ₄ → Cr ³⁺ yellow → blue (dichromate is reduced) (5) Carbon monoxide

[0038]

## STR6 ## CO + I ₂ O ₅ + H ₂ SO ₄ → I ₂ White → Brown (Iodine pentoxide is reduced) (6) Gas containing ethanol

[0039]

## ^STR7 ## C ₂ H ₅ OH + Cr ⁶⁺ + H ₃ PO ₄ → Cr ⁶⁺ yellow orange → light green (dichromate is reduced) (7) Ethylene

[0040]

Embedded image H ₂ C = CH ₂ + PdSO ₄ + (NH ₄ ) ₂ M
oO ₄ → Mo ₃ O ₈ pale yellow → blue (molybdate is reduced to form molybdenum blue) (8) Chlorine

[0041]

Embedded image

White → yellow orange (orthotrizine is oxidized to produce yellow holoquinone) (9) Gas containing xylene

[0043]

Embedded image C ₆ H ₄ (CH ₃ ) ₂ + I ₂ O ₅ + H ₂ SO
₄ → I ₂ white → brown (reacts with iodine pentoxide to release iodine) (10) Nitrogen dioxide

[0044]

Embedded image

White to pale green orange (reacts with ortho-tolidine to form nitroso ortho-tolidine) (11) Gas containing carbon disulfide

[0046]

Embedded image

Blue-violet to white (decomposes with an oxidizing agent to generate sulfurous acid gas, and this sulfurous acid gas bleaches tetrabase) (12) Propane

[0048]

^{Embedded image} CH ₃ CH ₂ CH ₃ + Cr ⁶⁺ + H ₂ SO ₄ → Cr ^{3 +} yellow orange → brown (potassium dichromate is reduced) (13) Gas containing formaldehyde

[0049]

Embedded image

White to orange-brown (reacts with aromatic compounds to produce dehydrated polycondensate) (14) Gas containing chlorine ion

[0051]

Embedded image Cl ⁻ + Ag ₂ CrO ₄ → AgCl brown → white (reacts with silver chromate to produce silver chloride)

[0052]

In summary, according to the present invention, no skill is required for the inspection and no complicated electric equipment is required. Therefore, the concentration of the dissolved gas in the liquid can be easily and inexpensively detected.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a dissolved gas indicator showing one embodiment of the present invention.

FIG. 2 is a side sectional view of a dissolved gas indicator showing another embodiment of the present invention.

FIG. 3 is a side sectional view showing a modified example of the dissolved gas indicator of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Dissolved gas indicator 20 Case 22 Gas inlet 32 Gas diffusion layer 34 Indicator layer 36 Indicator 40 Functional membrane

Claims (3)

[Claims] In a dissolved gas indicator for detecting the concentration of gas dissolved in a liquid, the gas inlet of a case containing an indicator for detecting the gas concentration is closed by the gas inlet to allow only gas to pass therethrough. A dissolved gas indicator comprising a functional film. 2. A case is provided with a gas diffusion layer for diffusing a gas introduced from a functional film into the case, and an indicator layer which reacts with the gas and changes color according to the gas concentration. Item 3. The dissolved gas indicator according to Item 1. 3. The dissolved gas indicator according to claim 1, wherein an indicator liquid that changes color according to the concentration of the gas introduced from the functional film is sealed in the case.