JP2004028738A - Hazardous substance concentration measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hazardous substance concentration measuring device for immediately measuring on site without requiring pretreatment. <P>SOLUTION: A device 10 measuring a concentration of a hazardous substance in atmosphere 100 which generates NO<SB>2</SB>through decomposition is provided with a detection agent having a carrier carrying a discoloring reagent in which the color thereof changes in reaction with NO<SB>2</SB>, a transparent and colorless detection tube 14 filled with the detection agent, graduations 14a provided on the detection tube 14 along with a longitudinal direction thereof, a thermal decomposition device 13 decomposing the hazardous substance in the atmosphere 100, a suction pump 15 circulating the hazardous substance decomposed by the thermal decomposition device 13 in the detection tube 14, a flow meter 12 adjusting an amount of air in the atmosphere 100 circulating by the thermal decomposition device 13, a timer 16, a pressure nanometer 17, and valves 18a and 18b, and so on. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a harmful substance concentration measuring device capable of easily measuring the concentration of harmful substances on site.
[0002]
[Prior art]
In a work site handling harmful substances, it is necessary to grasp the gas concentration of the harmful substance in the atmosphere of the work site. For this reason, for example, when measuring the concentration of hydrazine in the atmosphere of a work site, conventionally, for example, a certain amount of atmosphere is collected and passed through water, and hydrazine in the atmosphere is dissolved in water and collected. After that, the water was taken back to the analysis room and analyzed by liquid chromatography or the like.
[0003]
[Problems to be solved by the invention]
However, in the conventional method as described above, since it is necessary to perform pre-treatment and the like on the collected sample, not only cannot it be analyzed at the work site, but also it takes time to obtain the measurement result, There was no responsiveness.
[0004]
Therefore, an object of the present invention is to provide a harmful substance concentration measurement device that can be measured immediately on site without performing pretreatment.
[0005]
[Means for Solving the Problems]
The harmful substance concentration measuring device according to the first invention for solving the above-mentioned problem is a device for measuring the concentration in the atmosphere of a harmful substance which generates NO ₂ by decomposition, and reacts with NO _2. A detection agent in which a discoloring reagent that changes color is supported on a carrier, a colorless and transparent detection tube filled with the detection agent, a decomposition unit that decomposes the harmful substance in the atmosphere, and the decomposition unit that is decomposed by the decomposition unit. And a distribution means for causing the harmful substance to flow in the detection tube.
[0006]
The harmful substance concentration measuring device according to a second invention is characterized in that, in the first invention, a flow rate adjusting means for adjusting a flow rate of the atmosphere flowing through the decomposition means is provided.
[0007]
The harmful substance concentration measuring device according to a third invention is characterized in that, in the first or second invention, the detection tube is detachably held.
[0008]
A harmful substance concentration measuring apparatus according to a fourth invention is characterized in that, in any one of the first to third inventions, a scale is provided along a longitudinal direction of the detection tube.
[0009]
The harmful substance concentration measuring device according to a fifth invention is the thermal decomposition means according to any one of the first to fourth inventions, wherein the decomposition means heats the atmosphere to thermally decompose the harmful substance. It is characterized by the following.
[0010]
A harmful substance concentration measuring apparatus according to a sixth invention is characterized in that, in any one of the first to fifth inventions, the discoloring reagent is ortho-tolidine or N, N-diphenylbenzidine.
[0011]
The harmful substance concentration measuring apparatus according to a seventh invention is the harmful substance concentration measuring apparatus according to any one of the first to sixth inventions, wherein the harmful substance is hydrazine, dimethylhydrazine, ammonia, trimethylenetrinitroamine, diphenylamine, monomethylamine nitrate. , 1,2-propylene glycol dinitrate.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of a harmful substance concentration measuring apparatus according to the present invention will be described below with reference to FIGS. FIG. 1 is a schematic configuration diagram of the harmful substance concentration measuring device, and FIG. 2 is a graph of a calibration curve of the harmful substance concentration measuring device of FIG. Note that the present invention is not limited to the following embodiments.
[0013]
As shown in FIG. 1, a suction pipe 11 for sampling the atmosphere 100 at the work site is connected to one end of a quartz tube 13a via a flow meter 12. The periphery of the quartz tube 13a is surrounded by an electric heater 13b. The electric heater 13b is provided with a thermocouple 13c. The thermocouple 13c is connected to the input of the temperature controller 13d. The output of the temperature controller 13d is connected to the electric heater 13b.
[0014]
In other words, the temperature adjuster 13d can maintain the quartz tube 13a at a predetermined temperature by adjusting the heating temperature of the electric heater 13b based on the signal from the thermocouple 13c. In the present embodiment, the quartz tube 13a, the electric heater 13b, the thermocouple 13c, the temperature controller 13d, and the like constitute a thermal decomposition device 13 which is a thermal decomposition means.
[0015]
The other end of the quartz tube 13a is connected to one end of a detachable cartridge type detection tube 14 made of colorless and transparent glass having corrosion resistance and heat resistance. The inside of the detection tube 14 is filled with a detection agent in which a color-changing reagent such as ortho-tolidine or N, N-diphenylbenzidine that changes color by reacting with NO ₂ is supported on a carrier such as silica gel. A scale 14 a is provided near the detection tube 14 along the longitudinal direction of the detection tube 14.
[0016]
The other end of the detection tube 14 is connected to a suction pump 15. A timer 16 is connected to the suction pump 15, and the operation time of the suction pump 15 can be adjusted by the operation of the timer 16. In FIG. 1, 17 is a pressure gauge, and 18a and 18b are valves.
[0017]
In the present embodiment, a flow means is constituted by the suction pump 15 and the like, and a flow rate adjusting means is constituted by the suction pipe 11, the flow meter 12, the timer 16, the pressure gauge 17, the valves 18a and 18b, and the like.
[0018]
When the concentration of hydrazine, which is a harmful substance in the atmosphere of a work site, is measured using the harmful substance concentration measuring apparatus 10 according to the present embodiment, for example, the electric heater 13b of the thermal decomposition apparatus 13 is turned on. When the quartz tube 13a is operated to heat the quartz tube 13a to a predetermined temperature (about 250 to 400 ° C.) and the suction pump 15 is operated, the atmosphere 100 is sucked from the suction tube 11 and thermally decomposed via the flow meter 12 and the valve 18a. The hydrazine flows into the quartz tube 13a of the device 13, is heated to a predetermined temperature (about 300 ° C.), and the hydrazine contained therein is thermally decomposed to generate NO ₂ .
[0019]
The atmosphere 100, flows into the sensing tube 14 along with the decomposition gas of hydrazine containing NO _2, by which the NO ₂ reacts with discoloration reagent of the sensing agent, after discolor the detection agent (e.g., discoloration When the reagent is ortho-tolidine, the detector changes its color from white to yellow-orange (nitroso-ortho-tolidine), and when the reagent is N, N-diphenylbenzidine, the detector changes from white to blue (N, N-dinitrosodiphenylbenzidine) ), And is discharged from the suction pump 15 to the outside via the valve 18b.
[0020]
While the suction of the atmosphere 100 is checked by the flow meter 12 at a predetermined flow rate (approximately 50 to 100 cm ³ N / min) by the valves 18 a and 18 b, a predetermined time (about 15 to 60 minutes) is measured by the timer 16. 2), the higher the concentration of hydrazine in the sucked atmosphere 100, the longer the discoloration length of the detection tube 14 becomes. Therefore, as shown in FIG. The hydrazine concentration in the atmosphere 100 can be measured by measuring the discoloration length of the detection tube 14 on the scale 14a based on a calibration curve obtained in advance.
[0021]
Therefore, according to the harmful substance concentration measuring device 10 of the present embodiment, the concentration of hydrazine can be quickly measured with a simple device structure without performing a complicated pretreatment on the collected atmosphere 100. It can be measured immediately on site without pre-processing.
[0022]
The harmful substances include those containing at least one of hydrazine, dimethylhydrazine, ammonia, trimethylenetrinitroamine, diphenylamine, monomethylamine nitrate, and 1,2-propylene glycol dinitrate. However, any harmful substance that generates NO ₂ by decomposition can be applied in the same manner as in the present embodiment.
[0023]
Further, as a color-changing reagent, other than ortho-tolidine and N, N-diphenylbenzidine, any color-changing reagent that reacts with NO ₂ to change color can be applied in the same manner as in the present embodiment.
[0024]
【The invention's effect】
The harmful substance concentration measuring apparatus according to the first invention is an apparatus for measuring the concentration of harmful substances that generate NO ₂ by decomposition in an atmosphere, in which a discoloring reagent that changes color by reacting with NO ₂ is supported on a carrier. Detecting agent, a colorless and transparent detection tube filled with the detection agent, a decomposition means for decomposing the harmful substance in the atmosphere, and flowing the harmful substance decomposed by the decomposition means into the detection tube. Since it is equipped with a circulation means, the concentration of harmful substances can be quickly measured with a simple device structure without performing complicated pretreatment on the collected atmosphere, so on-site without pretreatment It can be measured immediately.
[0025]
The harmful substance concentration measuring device according to the second invention, in the first invention, includes a flow rate adjusting means for adjusting the flow rate of the atmosphere to be passed through the decomposition means, thereby facilitating quantitative measurement. Can be.
[0026]
The harmful substance concentration measuring device according to the third invention is the device according to the first or second invention, wherein the detection tube is detachably held, so that the used detection tube is replaced with a new detection tube. Can be easily performed, and work efficiency can be improved.
[0027]
The harmful substance concentration measuring device according to the fourth invention is characterized in that, in any one of the first to third inventions, a scale is provided along a longitudinal direction of the detection tube, thereby facilitating quantitative measurement. Can be planned.
[0028]
The harmful substance concentration measuring device according to a fifth invention is the thermal decomposition means according to any one of the first to fourth inventions, wherein the decomposition means heats the atmosphere to thermally decompose the harmful substance. Therefore, NO ₂ can be easily generated from harmful substances.
[0029]
The harmful substance concentration measuring apparatus according to a sixth aspect of the present invention is the harmful substance concentration measuring apparatus according to any one of the first to fifth aspects, wherein the color change reagent is ortho-tolidine or N, N-diphenylbenzidine, thereby facilitating the measurement. be able to.
[0030]
The harmful substance concentration measuring apparatus according to a seventh invention is the harmful substance concentration measuring apparatus according to any one of the first to sixth inventions, wherein the harmful substance is hydrazine, dimethylhydrazine, ammonia, trimethylenetrinitroamine, diphenylamine, monomethylamine nitrate. , 1,2-propylene glycol dinitrate, so that the above-described effects are most exhibited.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an embodiment of a harmful substance concentration measuring device according to the present invention.
FIG. 2 is a graph of a calibration curve of the harmful substance concentration measuring device of FIG.
[Explanation of symbols]
Reference Signs List 10 Harmful substance concentration measuring device 11 Suction tube 12 Flow meter 13 Pyrolyzer 13a Quartz tube 13b Electric heater 13c Thermocouple 13d Temperature regulator 14 Detector tube 14a Scale 15 Suction pump 16 Timer 17 Pressure gauge 18a, 18b Valve 100 Atmosphere

Claims (7)

An apparatus for measuring a concentration of a harmful substance which generates NO ₂ by decomposition in an atmosphere,
A detection agent in which a color changing reagent that changes color by reacting with NO ₂ is supported on a carrier;
A colorless and transparent detection tube filled with the detection agent,
Decomposition means for decomposing the harmful substance in the atmosphere;
A circulating means for circulating the harmful substance decomposed by the decomposing means into the detection tube. In claim 1,
A harmful substance concentration measuring device comprising a flow rate adjusting means for adjusting a flow rate of the atmosphere flowing through the decomposition means. In claim 1 or claim 2,
The harmful substance concentration measuring device, wherein the detection tube is detachably held. In any one of claims 1 to 3,
A harmful substance concentration measuring device, wherein a scale is provided along a longitudinal direction of the detection tube. In any one of claims 1 to 4,
The harmful substance concentration measuring device, wherein the decomposition means is a thermal decomposition means for heating the atmosphere to thermally decompose the harmful substance. In any one of claims 1 to 5,
The harmful substance concentration measuring device, wherein the discoloring reagent is ortho-tolidine or N, N-diphenylbenzidine. In any one of claims 1 to 6,
The harmful substance concentration measurement, wherein the harmful substance contains at least one of hydrazine, dimethylhydrazine, ammonia, trimethylenetrinitroamine, diphenylamine, monomethylamine nitrate, and 1,2-propylene glycol dinitrate. apparatus.

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