JPH0213486Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to an inspection hydrogen gas generator used for inspection of a gas sensor that has extremely high selectivity to hydrogen gas.

[Prior art]

As is well known, various safety devices such as household and industrial gas leak alarms that incorporate various gas sensors have become widespread. However, most of these gas sensors (chemical sensors) are subject to changes over time, which poses a serious problem from a safety standpoint. Therefore, maintenance and inspection of the gas sensor, which is the most important part of such safety equipment in practical terms, is essential, and inspection gas with an appropriate concentration is required for maintenance and inspection. . As such inspection gas,
Conventionally, organic solvents, organic solids, etc. that have an appropriate vapor pressure at room temperature have been used, or gas cylinders with predetermined concentrations have been used for substances that are gaseous at room temperature.

Incidentally, recently, gas sensors having extremely high selectivity for hydrogen have been developed and put into practical use, and therefore a test gas exclusively for hydrogen gas sensors has become necessary. In addition, the hydrogen gas generator for inspection is small, easy to use, and can be used for a long period of time, instead of being bulky and limited in the number of times it can be used like conventional gas cylinders. It has become desired.

[Summary of the idea]

This idea was developed in consideration of the above points, and is based on the principle of water electrolysis, and is based on the principle of water electrolysis. To provide a hydrogen gas generator for inspection, which can easily inspect a gas sensor over a long period of time by discharging inspection hydrogen gas in the gas storage lid after filling the gas storage lid. It is. This idea will be explained below.

[Example of idea]

Figure 1 is a sectional view showing an embodiment of this invention.
1 is a container made of a material that is not corroded by acids or the like. 2 is a small diameter opening formed at the bottom of the container 1, 3 is a small diameter opening formed at the top of the container 1, and 4 is a hydrogen gas for inspection (hereinafter simply H ₂ This is a gas storage lid for storing gas (referred to as gas), and is formed with an expandable bellows portion 5 and a conduction port 6 that fits into the opening 3. Reference numeral 7 denotes a cylindrical body provided inside the container 1, in which a large number of through holes 8 are formed. 9 is an opening 2 at the bottom of the container 1
10 is a negative electrode embedded in the opening 3 at the top of the container 1. Both electrodes 9 and 10 are gas permeable and liquid impermeable, that is, porous and repellent. It is formed by applying a powdered precious metal catalyst such as platinum black to a water-based fluororesin membrane (average pore diameter 5 to 20 μm, thickness 100 to 500 μm), etc.
In addition, H ₂ gas and O ₂ gas generated by electrolysis can be discharged to enable quick inspection, and on the other hand, when the container 1 is filled, the gas pressure inside the container 1 increases and the electrolyte 11 It also has the function of preventing leakage to the outside through each electrode 9, 10. Furthermore, as the container 1 becomes smaller, the effective area of each electrode 9, 10 becomes smaller, so noble metal powder is used to increase this effective area. Furthermore, the use of noble metal powder increases the efficiency of H ₂ gas generation. The electrolytic solution 11 used is a highly concentrated phosphoric acid aqueous solution, etc., which is hygroscopic at around room temperature, an electrolyte dissolved in a hydrophilic solvent with low vapor pressure, or a hygroscopic electrolyte dissolved in water. is used. Reference numeral 12 denotes a holding material filled in the cylindrical body 7, which is made of glass wool or the like and is impregnated with the electrolytic solution 11.The holding material 12 has a positive electrode 9 at the bottom and a negative electrode 10 at the top. There is. 13 is a power source connected to each of the electrodes 9 and 10, and uses a commercially available battery. 14 is a switch.

Next, the operation will be explained.

When the switch 14 of the power supply 13 is turned on, the electrolytic solution 11 impregnated in the holding material 12 is electrolyzed to generate O ₂ gas on the positive electrode 9 side and H ₂ gas on the negative electrode 10 side.
Gas is generated. The O ₂ gas then passes through the positive electrode 9 and diffuses to the outside. The _H2 gas passes through the negative electrode 10, passes through the opening 3 and the conduction port 6, and then passes through the gas storage lid 4.
It goes inside and is stored.

Figures 2a and b are explanatory diagrams showing the gas sensor inspection method, respectively. Figure 2a shows an example in which the detection method is a diffusion type, and uses the H ₂ gas generator for inspection shown in Figure 1. It is. FIG. 2b shows an example in which the gas detection method is a suction type.

In Figure 2a, when using the H ₂ gas generator for inspection, remove the gas storage lid 4 filled with H ₂ gas, rotate it 90 degrees in the direction of arrow A, hold it horizontally, and attach it to the gas sensor. The spray is applied by compressing the bellows part 5.

In FIG. 2b, the configuration of the container 1 of the H ₂ gas generator for inspection and each part inside the container 1 is the same as in FIG. 1, but the difference from FIG.
The structure is as follows. In the gas storage lid 21, 22 is
_H2 gas communication port, 23 is _H2 gas when inspecting the gas sensor.
This is an air inlet through which air is introduced after gas is exhausted.

When inspecting a gas sensor equipped with an automatic suction device, remove the gas storage lid 21 filled with H ₂ gas, rotate it 90 degrees in the direction of arrow B, and hold it horizontally, as in the case of Fig. 2a. Gas sensor suction port 24
When brought into contact with the gas sensor, the H ₂ gas in the gas storage lid 21 is discharged from the communication port 22 and guided to the gas sensor by suction from the gas sensor, and at the same time, external air is introduced from the air introduction port 23.

Fig. 3 is a characteristic diagram when the inspection _H2 gas generator using the gas storage lid 21 shown in Fig. 2b is operated.
It shows the amount of hydrogen gas generated (ppm) and the gas sensor output (mV) with respect to the operating time when the switch 14 in FIG. 1 is turned on and off. In this figure, the operating voltage is 2.40V, and in the figure, is on for 2 seconds and off for 1 minute, repeated 3 times, is on for 3 seconds and off for 1 minute, repeated 3 times, and is on for 4 seconds. 3 when turned off for 1 minute
"Repetition times" indicates a case in which two repetitions of turning on for 5 seconds and turning off for 1 minute are performed consecutively. As is clear from this characteristic diagram, the hydrogen gas generator for inspection of this invention has good reproducibility and quantification of the amount of H ₂ gas generated, and the output response of the gas sensor is fast. Therefore, the desired amount of H ₂ gas generated is
It can be freely obtained by changing the operating voltage and operating time.

Note that in the above embodiment, the holding material 12 is housed in the cylindrical body 7 having the through hole 8, but the holding material 12 itself is formed into a cylindrical shape and disposed between the positive electrode 9 and the negative electrode 10. If this is done, the cylindrical body 7 can be omitted.

[Effect of idea]

As explained above, this device has small-diameter openings at the top and bottom of the container that stores the electrolytic solution that generates hydrogen gas for inspection, and uses these openings to decompose water and generate hydrogen gas for inspection. A gas-permeable but liquid-impermeable negative electrode and a positive electrode are arranged, and a holding material impregnated with electrolyte is arranged between these electrodes, and hydrogen gas for inspection is discharged to the outside from the opening. Since the gas storage lid for storing the gas is removably provided at the opening, the gas sensor can be inspected immediately by blowing or introducing the inspection gas in the gas storage lid onto the gas sensor. It also has the advantage of being able to operate satisfactorily with commercially available batteries, quantitatively generating H ₂ gas for inspection, and being usable for a long period of time.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of this invention, Figs. 2 a and b are explanatory diagrams showing the gas sensor inspection method, and Fig. 3 is the characteristics when the hydrogen gas generator for inspection of this invention is operated. It is a diagram. In the figure, 1 is a container, 2 and 3 are openings, 4 is a gas storage lid, 5 is a bellows part, 6 is a conduction port, 7 is a cylindrical body, and 8
1 is a through hole, 9 is a positive electrode, 10 is a negative electrode, 11 is an electrolytic solution, 12 is a holding material, 13 is a power source, and 14 is a switch.

Claims (1)

[Scope of utility model registration request] Small-diameter openings are provided at the upper and lower parts of a container that stores an electrolytic solution for generating hydrogen gas for inspection, respectively, and gas permeability is provided in both of these openings to electrolyze the electrolytic solution and generate the hydrogen gas for inspection. A liquid-impermeable negative electrode and a positive electrode are provided, a holding material impregnated with the electrolytic solution is provided between these electrodes, and hydrogen gas for inspection to be discharged to the outside from the opening is stored. A hydrogen gas generator for inspection, characterized in that a gas storage lid is detachably provided in the opening.