JPS6228646A - Diaphragm type ozone sensor - Google Patents

Abstract

PURPOSE:To exactly measure ozone concn. without being affected by other gaseous components by sealing a material which generates chemical emission of light by reacting with ozones in a container having light transmission window on one side and a gas permeable diaphragm on the other side and providing a photodetector thereto. CONSTITUTION:The ozones in the gas to be measured pass the gas permeable diaphragm 10 and intrude into the container 4 when a cap body 14 is removed and the container is put into the gas to be measured. Then the ozones induce the chemical reaction with ethylene 13 in the container 4 and generates the chemical emission of light. The generated light is transmitted through an optical transmission window 9 and is measured by the photodetector 2 consisting of a photomultiplier tube, etc. in a cylindrical body 1. The ozone concn. is measured from the intensity of the chemical emission of light. Part of the ethylene 13 in the container emerges from the container 4 to the outside through the diaphragm 10 and generates the chemical emission by effecting the chemical reaction with the ozones in the gas near the diaphragm 10. Since the inside surface of the container 4 is mirror-finished, both rays of the chemically emitted light advance toward the photodetector 12 side.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a diaphragm type ozone sensor.

[Conventional technology]

Conventionally, there is a method using chemiluminescence to measure the ozone concentration in gas. This means that ozone is chH4 (
The chemiluminescence intensity when reacting with specific substances such as ethylene) and No (nitrogen oxide) is measured by a photodetector, and the ozone concentration in the gas is measured from the chemiluminescence intensity.

Fig. 2 shows an outline of the ozone concentration measuring device using the chemiluminescence method described above, in which 30 is a reaction tank, 31 is an ethylene supply pipe, 32 is a sample gas supply pipe to be measured, and 33 is an exhaust gas. With pipes, these pipes 3
1, 32, and 33 are connected to the reaction tank 30, respectively. 3
4 is a photodetector such as a photomultiplier tube, 35 is an amplifier, 36 is an indicator recorder, and 37 is a high voltage ms.

38 is a filter, 39 is a regulator, 40 is a pressure gauge, 41 is an ethylene flow rate adjustment valve, 42 is an ethylene flowmeter, 43 is a flowmeter, 44 is a pump, 45 is an ethylene removal device, 46 is a sample gas flow fi adjustment valve It is.

Ethylene and sample gas are introduced into the reaction tank 30, and ozone contained in the sample gas reacts with ethylene to produce chemiluminescence. In this case, if an excessive ozone concentration higher than the ethylene concentration is maintained, the chemiluminescence intensity is proportional to the ozone concentration, so by measuring the chemiluminescence intensity with the photodetector 34, the ozone concentration in the sample gas can be determined. It can be measured.

[Problem that the invention seeks to solve]

However, in the above measuring device, the reaction tank 30
and pipe 3 for introducing ethylene and sample gas into this.
It requires complicated piping such as 1.32 and pipe 33 for deriving the gas after the reaction, making the overall structure of the device large-scale.
In addition to being extremely difficult to carry easily, this measuring device can measure the concentration of ozone in gas, but cannot measure the concentration of ozone dissolved in liquid.

In contrast, diaphragm type ozone sensors such as constant potential electrolysis type (direct electrolysis or measurement by converting ozone into oxygen), galvanic cell type, and coulometric type are being considered.

However, conventional diaphragm-type ozone sensors cannot handle other gases (
For example, COx, HzS, HCI, SOx, N
Ozone concentration is difficult to measure accurately due to the lack of selectivity due to the interference of ozone (Ox, etc.).

The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to provide a simple diaphragm-type ozone sensor that can selectively detect only ozone and accurately measure its concentration. be.

[Means for solving problems]

A cylindrical body containing a substance that reacts with ozone to produce chemiluminescence and equipped with a photodetector, with the diaphragm side facing outward;
The container can be detachably attached.

[Effect]

In the above configuration, the light transmitting window is made of polytetrafluorethylene, for example, which easily transmits a substance that reacts with visible light and ozone to produce chemiluminescence. Substances that react with ozone to produce chemiluminescence include olefinic hydrocarbons such as ethylene, No.
Examples include solutions of gases), Rhodamine B, Luminol, Methylene Pur, and the like.

Thus, for example, the ethylene gas enters a container filled with ethylene through a filling diaphragm and causes a chemical reaction with the ethylene in the container, producing chemiluminescence.

The intensity of this chemiluminescence is measured by a photodetector, and the ozone concentration can be determined from the intensity of chemiluminescence.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a diaphragm type ozone sensor according to the present invention. In the figure, 1 is a cylindrical body, and a photodetector 2 made of a photomultiplier tube, a semiconductor photoelectric element, or the like is provided at the end of the cylindrical body. 3 is a threaded portion formed on the outer periphery of the end of the cylinder l.

Although not shown, the output of the photodetector 2 is appropriately amplified and displayed on an indicator.

Reference numeral 4 denotes a container that is detachably attached to the end of the cylindrical body 1, and has a threaded portion 5 screwed into the threaded portion 3 on the inner periphery of the end.
However, a threaded portion 8 is formed on the outside to be screwed into the threaded portion 7 of the diaphragm fixing device 6.

Reference numeral 9 denotes a light transmitting window, which is made of, for example, quartz glass that easily transmits chemiluminescence in the visible light range, and is detachably held on one side of the container 4 (on the threaded portion 5 side).

Reference numeral 10 denotes a gas-permeable diaphragm made of, for example, polytetrafluorethylene, which allows ozone and substances that react with ozone to produce chemiluminescence to permeate easily;
A sealing member 11 such as an O-ring and a diaphragm support 12 are interposed at the other end (on the opposite side to the threaded portion 5) of the diaphragm fixing device 6, so that the diaphragm fixing device 6 is tightened to be removably held.

Note that the inner surface of the container 4 has a mirror finish. Further, the container 4 is made of a material such as stainless steel, which is not easily affected by ozone and substances that react with ozone to produce chemiluminescence.

13 is a substance sealed in the container 4 that reacts with ozone to produce chemiluminescence, such as ethylene. this thing'
It13 is introduced into the container 4 through a specific substance inlet (not shown) provided in the container 4 by an appropriate method. 1
4 is a lid for sealing the diaphragm 10 side, and is detachably attached to the diaphragm fixture 6.

Therefore, when measuring the ozone concentration in gas using the diaphragm type ozone sensor configured as described above, the measurement is performed with the container 4 containing ethylene 13 attached to the cylinder 1 equipped with the photodetector 2. (The M body 14 is removed), the ozone in the gas passes through the gas-permeable diaphragm 1.
o into the container 4, and the ethylene 13 in the container
A chemical reaction occurs, and at this time chemiluminescence is produced. The intensity of this chemiluminescence is measured by a photodetector, and the ozone concentration can be determined from the chemiluminescence intensity.

Note that ozone in the gas selectively passes through the diaphragm 10 into the container 4.
During a chemical reaction with ethylene 13 in the container 4, part of the ethylene in the container 4 passes through the diaphragm 10 and exits the container 4, causing ozone in the gas near the diaphragm 10 to A chemical reaction takes place, which also produces cultural luminescence. container 4
Since the inner surface of the detector is mirror-finished, all of the chemiluminescence described above is directed toward the photodetector 2. Furthermore, the substance sealed in the container 4 is not limited to ethylene, but may also be olefinic hydrocarbons or nitrogen monoxide. Alternatively, a solution of rhodamine B, luminol, methylene blue, etc. may be enclosed. When these solutions are used, it is possible to measure the degree of ozone dissolved in the liquid. In addition, the diaphragm 10
Since the amount of ozone transmitted at
It is desirable to correct the output signal of

C Effect of the invention] A substance that reacts with ozone to produce chemiluminescence is sealed in a container provided with a membrane, and the container is placed in a cylinder provided with a photodetector so that the diaphragm side faces outward. Since it is removably attached, it is possible to selectively detect only ozone, and accurately measure the concentration of ozone in both gas and liquid without any interference from other component gases. It can be measured. Furthermore, the overall configuration of the device is extremely simplified compared to conventional ozone sensors of this type, and therefore, it can be easily carried.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a diaphragm type ozone sensor according to the present invention, and FIG. 2 is a configuration diagram for explaining the prior art. DESCRIPTION OF SYMBOLS 1... Cylindrical body, 2... Photodetector, 4... Container, 9...
...Light transmission window, 10...Diaphragm, 13...Substance that reacts with ozone to produce chemiluminescence.

Claims (1)

[Claims] A substance that reacts with ozone to produce chemiluminescence is sealed in a container equipped with a light-transmitting window on one side and a gas-permeable diaphragm on the other, and a cylindrical body equipped with a photodetector is placed with the diaphragm side facing outward. A diaphragm type ozone sensor, characterized in that the container can be detachably attached so as to face the container.