JPS6066140A - Sensor for concentration of oxygen - Google Patents

Abstract

PURPOSE:To discriminate the concn. of O2 with a simple device by passing a gas contg. sample O2 through a detecting part provided with a heating element which is preliminarily conducted with electricity and observing a physical change such as luminance, etc. of the heating element thereby detecting whether an oxygen generator for medical purpose or the like generates gaseous O2 at a specified concn. or above or not. CONSTITUTION:A heating element 13 to which current of, for example, a specified voltage, is passed from an electric power source 20 is provided to the inside of a detecting part having a part 11 for introducing the gas contg. concd. O2 from an oxygen generator and a part 12 for leading out said gas. The luminance of the heating element is observed visually by making use of the phenomenon in which the quantity of the current is changed by the concn. of the gaseous O2 introduced into said detecting part. Or a liquid crystal 30 is preliminarily deposited by evaporation on the surface of the element 13 and the change in the liquid crystal 30 owing to the heat generated by the heating element is visually observed. The concn. of the gaseous O2 is discriminated by observing the physical change in the above-mentioned manner. The throw-away use of the element 13 at every checking of the concn. of O2 is thus made possible by using such extremely simple and inexpensive detecting part 13.

Description

[Detailed description of the invention] The present invention relates to an oxygen concentration sensor.

Oxygen generators are generally known as devices that condense oxygen gas in the atmosphere and generate highly concentrated oxygen gas, and are widely used in various fields including medicine.

By the way, in order to measure the concentration of the generated oxygen gas, platinum electrodes were attached to both sides of the zirconia porcelain, and a predetermined voltage was applied to the electrodes at a high temperature of several hundred degrees or more.
A zirconia-type oxygen concentration sensor is known that measures the oxygen concentration by measuring the amount of oxygen ions flowing at that time.

However, with this zirconia sensor, the output necessary for detection cannot be obtained unless the zirconia part is heated to a high temperature (approximately 700°C), and stable measurement is difficult due to the poor adhesion between the zirconia and platinum electrodes. However, the sensor itself is bulky and expensive due to the need for heating and insulation.

Therefore, it is not preferable to apply such a zirconia sensor to, for example, the above-mentioned medical oxygen generator. This is because in medical applications, etc., it is rare to know the concentration in exact numbers, and it is important to know whether or not oxygen gas is being generated at a certain concentration or higher from the oxygen generator, and it is also important to note that Since it is used by inexperienced people, it must be easy to operate, and it must not be too expensive compared to oxygen generators. The purpose of the present invention is to provide an oxygen concentration sensor that is easy to operate, inexpensive, and compact.

Hereinafter, embodiments of the present invention will be described based on the drawings. Figure 1 shows a schematic configuration of an oxygen concentration sensor according to the present invention. ) and an outlet section (6) for discharging the concentrated 02, and has a heating element (2) such as a filament inside. The heating element is made of, for example, an ultrafine wire made of tungsten, molybdenum, or carbon, and is configured to be supplied with a constant voltage or current by a power source (4).

Therefore, when the heating element (to) is energized while feeding concentrated 0□ from a medical oxygen generator (not shown) through the introduction part αυ to the detection part α1, the heating element (to) is heated by the oxygen partial pressure. )
They exhibit physical changes such as simply generating heat, becoming darker due to oxides adhering to the surface, becoming thinner and shining as the oxides scatter, or being further oxidized and breaking like a fuse. The degree of physical change that occurs due to the reaction between the heating element Q3 and oxygen is determined by the concentration of concentrated 0□ introduced when the voltage or current applied to the heating element α is constant. is proportional to.

Therefore, in order to make it possible to visually confirm the physical change in the heating element (2) when electricity is applied, part or all of the detection part QO in which the heating element (2) is installed is made of transparent glass or resin, etc. do. By doing this, for example, the magnitude of the brightness of the heating element can be roughly grasped visually, and it is also possible to confirm that the oxidation progresses and the wire is disconnected. Furthermore, as shown in FIG. 2, a liquid crystal layer may be deposited on the heating element (1), and changes in the liquid crystal α due to heat generated by the heating element (1) may be visually observed.

As described above, the present invention introduces a gas containing oxygen into a detection section, and when electricity is applied to a heating element provided in the detection section, the concentration of the oxygen gas is determined by a physical change caused by a reaction between the heating element and oxygen. Since it is constructed so that it can be determined, it is easy to handle unlike a zirconia type cell, and it is also compact, so even people with little specialized knowledge can use it easily. Furthermore, since the configuration is much simpler than that of a zirconia sensor, it is inexpensive, and the heat generating part can be thrown away each time the oxygen concentration is checked. In this way, it is less expensive than oxygen generators, and is especially useful in cases such as medical oxygen generators, where you only need to check whether oxygen gas is being generated at a predetermined concentration or higher. preferred '0

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an example of the configuration of an oxygen concentration sensor according to the present invention, and FIG. 2 is an explanatory diagram showing the configuration of a detection section. OO...Detection part, α purifier...Heating element. Figure 1 2 Figure 2

Claims (1)

[Claims] An oxygen concentration sensor in which a gas containing oxygen gas is introduced into a detection part, and when a heating element provided in the detection part is energized, the concentration of the oxygen gas can be determined based on a physical change in the heating element.