JP2016003929A - Carbonyl sulfide concentration measuring apparatus and carbonyl sulfide concentration measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carbonyl sulfide concentration measuring apparatus and a carbonyl sulfide concentration measuring method, capable of continuously and accurately measuring concentration of carbonyl sulfide contained in gases including air.SOLUTION: A carbonyl sulfide concentration measuring apparatus includes: a purification cylinder 13 that allows absorption of other components than carbonyl sulfide contained in a sample gas and then allows passage of the carbonyl sulfide; a catalyst cylinder 21 that generates hydrogen sulfide from the carbonyl sulfide after passing through the purification cylinder 13, through hydrolysis reaction; a hydrogen sulfide concentration measuring instrument 34 that measures concentration of the hydrogen sulfide generated in the catalyst cylinder 21; and a calculation part 42 that calculates concentration of carbonyl sulfide contained in the sample gas on the basis of the hydrogen sulfide concentration measured by the hydrogen sulfide concentration measuring instrument 34 and a carbonyl sulfide-to-hydrogen sulfide conversion efficiency preliminarily acquired in the catalyst cylinder 21 with respect to standard gas.

Description

  The present invention relates to a carbonyl sulfide concentration measuring apparatus and a carbonyl sulfide concentration measuring method capable of measuring the concentration of carbonyl sulfide contained in a gas containing air continuously and accurately.

  In recent years, carbonyl sulfide has been rapidly used and used as an etching gas in the field of semiconductor materials. Carbonyl sulfide is known as a highly toxic gas. For this reason, it is important to continuously monitor the concentration of carbonyl sulfide in the working environment.

In the United States, in 2012, a new allowable carbonyl sulfide concentration (TLV value) of carbonyl sulfide was set at 5 ppm.
Conventionally, a gas chromatograph using a gas chromatography method, a detection device employing an electrolytic detection method, or the like is used to measure the concentration of carbonyl sulfide.
Patent Document 1 discloses analyzing carbonyl sulfide using a gas chromatography method.

Japanese Examined Patent Publication No. 6-7127

  However, when the concentration of carbonyl sulfide contained in a gas containing air is detected using the gas chromatography method disclosed in Patent Document 1, carbonyl sulfide contained in the gas and other components are detected before the detection. It is necessary to separate the components. For this reason, there existed a problem that the density | concentration of carbonyl sulfide could not be acquired continuously.

  On the other hand, when carbonyl sulfide contained in a gas is detected using a detection method based on an electrolytic method, continuous analysis and detection are possible, but detection sensitivity (for example, 20 to 30 ppm) is high. Since it is low, there is a problem that it is impossible to obtain a highly accurate carbonyl sulfide concentration (in other words, it is not possible to measure 5 ppm which is an allowable concentration (TLV value) of carbonyl sulfide).

  As described above, there has been no method and apparatus that can continuously and accurately detect the concentration of carbonyl sulfide contained in a gas containing air. On the other hand, a method and an apparatus capable of accurately detecting the concentration of hydrogen sulfide exist in the world.

  The present inventors do not directly measure carbonyl sulfide contained in a gas containing air, but generate hydrogen sulfide from carbonyl sulfide, continuously detect the concentration of the hydrogen sulfide, and obtain it continuously. Carbonyl sulfide contained in the gas based on the result of the concentration of hydrogen sulfide to be converted and the ratio of conversion of carbonyl sulfide with a known concentration contained in the standard gas to hydrogen sulfide and the conversion efficiency obtained in advance. It came to the idea of converting and measuring the density | concentration of this.

  Accordingly, an object of the present invention is to provide a carbonyl sulfide concentration measuring apparatus and a carbonyl sulfide concentration measuring method capable of measuring the concentration of carbonyl sulfide contained in a gas containing air in a continuous and accurate manner. To do.

  In order to solve the above-mentioned problem, according to the invention according to claim 1, a component other than the carbonyl sulfide contained in the sample gas is adsorbed, and the purified cylinder is allowed to pass through the carbonyl sulfide by a hydrolysis reaction. A catalyst cylinder that generates hydrogen sulfide from the carbonyl sulfide that has passed, a hydrogen sulfide concentration measuring device that measures the concentration of the hydrogen sulfide generated in the catalyst cylinder, and the hydrogen sulfide that is measured by the hydrogen sulfide concentration measuring instrument And the conversion efficiency obtained in advance in the catalyst cylinder, and the conversion efficiency obtained in advance is a ratio in which the carbonyl sulfide having a known concentration contained in the standard gas is converted into hydrogen sulfide, and the sample gas contains There is provided a carbonyl sulfide concentration measuring device characterized by having an arithmetic unit for calculating the concentration of carbonyl sulfide.

  Moreover, according to the invention which concerns on Claim 2, the said refinement | purification cylinder has a cylinder main body and the aluminosilicate zeolite with which the said cylinder main body was filled, The carbonyl sulfide density | concentration of Claim 1 characterized by the above-mentioned. A measuring device is provided.

  The invention according to claim 3 further includes a moisture addition unit that adds moisture to the carbonyl sulfide that has passed through the purification cylinder and supplies the carbonyl sulfide containing the moisture to the catalyst cylinder. A carbonyl sulfide concentration measuring device according to claim 1 or 2 is provided.

  According to a fourth aspect of the present invention, the apparatus includes a flow rate adjusting unit that is arranged upstream or downstream of the hydrogen sulfide concentration measuring device and adjusts the flow rate of the hydrogen sulfide supplied to the hydrogen sulfide concentration measuring device. A carbonyl sulfide concentration measuring device according to any one of claims 1 to 3 is provided.

  Further, according to the invention of claim 5, a carbonyl sulfide obtaining step for selectively obtaining carbonyl sulfide contained in the sample gas, and a sulfide for producing hydrogen sulfide from the carbonyl sulfide by a hydrolysis reaction using a catalyst. A hydrogen generation step, a hydrogen sulfide concentration measurement step for measuring the concentration of hydrogen sulfide, a concentration of the hydrogen sulfide measured in the hydrogen sulfide concentration measurement step, and a carbonyl sulfide having a known concentration contained in a standard gas is sulfided. And a carbonyl sulfide concentration measurement step for measuring the concentration of the carbonyl sulfide contained in the sample gas by calculation based on the conversion efficiency obtained in advance and the conversion efficiency obtained in advance. A carbonyl sulfide concentration measuring method is provided.

  Moreover, according to the invention which concerns on Claim 6, in the said carbonyl sulfide acquisition process, an aluminosilicate zeolite is used, The carbonyl sulfide concentration measuring method of Claim 5 characterized by the above-mentioned is provided.

  Further, according to the invention according to claim 7, the method further comprises a water addition step of adding water to the carbonyl sulfide between the carbonyl sulfide acquisition step and the hydrogen sulfide generation step. 6. A method for measuring a carbonyl sulfide concentration according to 6, is provided.

  According to an eighth aspect of the present invention, the catalyst cylinder is heated so that the temperature of the catalyst cylinder becomes a predetermined temperature within a range of 60 to 120 degrees. 7. The method for measuring a carbonyl sulfide concentration according to any one of 7 is provided.

  Moreover, according to the invention which concerns on Claim 9, it adjusts so that the flow volume of the said hydrogen sulfide supplied to the said hydrogen sulfide concentration measuring device may become predetermined | prescribed flow volume, A method for measuring a carbonyl sulfide concentration according to claim 1 is provided.

  According to the carbonyl sulfide concentration measuring apparatus and the carbonyl sulfide concentration measuring method of the present invention, the concentration of carbonyl sulfide contained in a gas containing air can be measured continuously and accurately.

It is a figure (system diagram) which shows typically a schematic structure of a carbonyl sulfide concentration measuring device concerning an embodiment of the invention. It is a graph which shows the relationship between the density | concentration of the known carbonyl sulfide contained in standard gas G1-G6, and the density | concentration of the hydrogen sulfide produced | generated by hydrolyzing the carbonyl sulfide contained in standard gas G1-G6. It is an apparatus for refined cylinder evaluation for confirming the effect of the refined cylinder used in Test Example 2. During non-purified H ₂ S, and is a diagram showing voltage strength (Output) of the _H 2 S contained in the standard gas H1 (hydrogen sulfide) during the purification of _{H 2} S. During non Purification of SO _2, and illustrates the voltage intensity (Output) of _SO 2 S contained in the standard gas H2 (sulfur dioxide) during purification SO _2. It is a figure which shows the voltage intensity | strength (Output) of COS (sulfur dioxide) contained in standard gas H3 at the time of the non-purification of COS, and the refinement | purification of COS. CH ₃ SH during non purification, and is a diagram showing a voltage intensity of _CH 3 SH in the standard gas H4 (methanethiol) (Output) during the purification of _CH 3 SH. It is a figure which shows the voltage intensity | strength (Output) of DMS (dimethyl sulfide) contained in standard gas H5 at the time of the non-purification of DMS, and the refinement | purification of DMS. It is a figure which shows the voltage intensity | strength (Output) of DMDS (dimethyl disulfide) contained in the standard gas H6 at the time of the non-purification of DMDS, and the refinement | purification of DMDS.

  Embodiments to which the present invention is applied will be described below in detail with reference to the drawings. The drawings used in the following description are for explaining the configuration of the embodiment of the present invention, and the size, thickness, dimension, etc. of each part shown in the figure are the dimensional relationship of an actual carbonyl sulfide concentration measuring device. May be different.

(Embodiment)
FIG. 1 is a diagram (system diagram) schematically showing a schematic configuration of a carbonyl sulfide concentration measuring apparatus according to an embodiment of the present invention.

Referring to FIG. 1, a carbonyl sulfide concentration measuring apparatus 10 according to the present embodiment measures the concentration of carbonyl sulfide contained in air (for example, an atmosphere around a semiconductor manufacturing apparatus) or gas (for example, a sample gas). A sample gas supply line 11, a purification cylinder 13, a carbonyl sulfide supply line 14, valves 16, 26, and 28, a moisture addition unit 17, a moisture-containing carbonyl sulfide supply line 19, and a catalyst cylinder 21. The heating unit 23, the first hydrogen sulfide supply line 24, the bypass line 27, the flow rate adjusting unit 31, the second hydrogen sulfide supply line 33, the hydrogen sulfide concentration measuring device 34, the exhaust line 36, And a control device 37.
In the present embodiment, as an example, the following description will be given by taking as an example the case of supplying a sample gas containing carbonyl sulfide from one end of the sample gas supply line 11.

  In the sample gas supply line 11, the sample gas is introduced from one end, and the other end is connected to one end of the purification cylinder 13. The sample gas supply line 11 is a line for supplying a sample gas containing carbonyl sulfide to the purification cylinder 13.

The other end of the purification cylinder 13 is connected to one end of the carbonyl sulfide supply line 14. The refined cylinder 13 includes a cylinder main body 13-1 and an aluminosilicate zeolite 13-2 having an effective pore diameter of 0.3 nm or less.
The cylinder body 13-1 has a hollow portion (not shown) therein. The aluminosilicate zeolite 13-2 is disposed so as to fill a hollow portion (not shown) of the cylinder body 13-1.

Thus, by using the aluminosilicate zeolite 13-2 as a constituent element of the purification cylinder 13, components other than carbonyl sulfide contained in the sample gas can be adsorbed and carbonyl sulfide can pass therethrough.
It is to be noted that the moisture contained in the sample gas by passing through the aluminosilicate zeolite 13-2 (in other words, necessary for performing a catalytic reaction (reaction for converting carbonyl sulfide into hydrogen sulfide by hydrolysis) in the catalyst cylinder 21). Water) is removed.

As the aluminosilicate zeolite 13-2, for example, 3A type aluminosilicate zeolite can be used. Further, as a specific 3A type aluminosilicate zeolite, for example, Molecular Sieve 3A (product name) manufactured by GL Science Co., Ltd. having an effective pore diameter of 0.3 nm can be used.
The purification cylinder 13 adsorbs components other than carbonyl sulfide contained in the sample gas and allows the carbonyl sulfide to pass therethrough.

  In the present embodiment, as an example of the adsorbent that constitutes the purification cylinder 13, the case where the aluminosilicate zeolite 13-2 is used has been described as an example. However, the adsorbent that constitutes the purification cylinder 13 is What is necessary is just to be able to adsorb components other than carbonyl sulfide contained in the sample gas, and it is not limited to the aluminosilicate zeolite 13-2.

The other end of the carbonyl sulfide supply line 14 is connected to one end of the moisture addition unit 17. The carbonyl sulfide supply line 14 is a line for supplying the carbonyl sulfide that has passed through the purification cylinder 13 to the moisture addition unit 17.
The valve 16 is provided in the carbonyl sulfide supply line 14. When the valve 16 is opened, carbonyl sulfide is supplied to the moisture addition unit 17. When the valve 16 is closed and when the valve 28 is opened, the bypass line 27 and the first hydrogen sulfide supply line 24 are used. The carbonyl sulfide is supplied to the flow rate control unit 31.

The other end of the moisture addition unit 17 is connected to one end of the moisture-containing carbonyl sulfide supply line 19. The moisture addition unit 17 adds moisture to the carbonyl sulfide supplied via the carbonyl sulfide supply line 14.
Thus, by having the water addition part 17 arrange | positioned in the front | former stage of the catalyst cylinder 21, water | moisture content (required for the catalytic reaction in the catalyst cylinder 21) to the carbonyl sulfide from which the water | moisture content was removed by the aluminosilicate zeolite 13-2. Water) can be added. Thereby, in the catalyst cylinder 21, carbonyl sulfide can be hydrolyzed to hydrogen sulfide.

As the moisture addition unit 17, for example, a moisture permeable tube (specifically, for example, a Teflon (registered trademark) tube), a bubbling mechanism, a wet gas generated by a standard gas (or permeator) is converted into carbonyl sulfide. An example is a moisture application system in which a certain amount is mixed.
When reducing the weight of the carbonyl sulfide concentration measuring device 10, it is preferable to use, for example, a moisture permeable tube (specifically, for example, a Teflon (registered trademark) tube) or a bubbling mechanism as the moisture addition unit 17. .
Moreover, when the weight of the carbonyl sulfide concentration measuring apparatus 10 is not considered so much, it is preferable to use, for example, the above-described moisture application system as the moisture addition unit 17. By using the moisture application system, the concentration of water added to carbonyl sulfide can be controlled with high accuracy.

  For example, the moisture addition unit 17 may add moisture to such an amount that the moisture concentration of the carbonyl sulfide containing moisture led out to the moisture-containing carbonyl sulfide supply line 19 becomes a predetermined concentration within the range of 1 to 100 ppm.

  In addition, in the purification cylinder 13, in place of the aluminosilicate zeolite 13-2, an adsorbent capable of removing components other than carbonyl sulfide contained in the sample gas without depriving the moisture contained in the sample gas ( Alternatively, when the removing agent is used, the water addition unit 17 does not need to be provided in the front stage of the catalyst cylinder 21.

  The other end of the moisture-containing carbonyl sulfide supply line 19 is connected to one end of the catalyst cylinder 21. The moisture-containing carbonyl sulfide supply line 19 is a line for supplying carbonyl sulfide to which moisture has been added to the catalyst cylinder 21 from the moisture addition unit 17.

The other end of the catalyst cylinder 21 is connected to one end of the first hydrogen sulfide supply line 24. The catalyst cylinder 21 includes a cylindrical member 21-1 and a catalyst 21-2.
The cylindrical member 21-1 has a hollow portion (not shown) therein. As a material of the cylindrical member 21-1, for example, stainless steel can be used.

The catalyst 21-2 is filled in a hollow portion (not shown) of the cylindrical member 21-1. The catalyst 21-2 is for hydrolyzing the carbonyl sulfide that has passed through the purification cylinder 13 into hydrogen sulfide.
As the catalyst 21-2, for example, alumina granules can be used. When alumina granules are used as the catalyst 21-2, the shape thereof can be, for example, a cylindrical shape. In this case, for example, the diameter can be 1 mm and the length can be 3 mm.

  The heating unit 23 includes a hot wire 23-1 (a heating element) and a power source 23-2. The hot wire part 23-1 is wound around the outer periphery of the catalyst cylinder 21. One end of the heating unit 23 is connected to one terminal (for example, a plus terminal) of the power source 23-2, and the other end is connected to the other terminal (for example, a minus terminal) of the power source 23-2. .

The heating unit 23 configured as described above is configured so that the temperature of the catalyst cylinder 21 (specifically, the catalyst 21-2) becomes a predetermined temperature in a state where carbonyl sulfide containing moisture is supplied to the catalyst cylinder 21. The catalyst cylinder 21 is heated.
When using alumina granules as the catalyst 21-2, the heating unit 23 performs heating so that the temperature of the catalyst cylinder 21 (specifically, the catalyst 21-2) is within a range of 60 to 120 degrees.
Thus, by having the heating part 23 heated so that the temperature of the catalyst cylinder 21 (specifically, the catalyst 21-2) is within a range of 60 to 120 degrees (preferably 85 degrees), sulfurization is performed. The hydrolysis reaction at the time of producing hydrogen can be promoted.

The other end of the first hydrogen sulfide supply line 24 is connected to the flow rate adjusting unit 31. The first hydrogen sulfide supply line 24 is a line for supplying the hydrogen sulfide generated in the catalyst cylinder 21 to the flow rate adjusting unit 31.
The valve 26 is disposed in a portion of the first hydrogen sulfide supply line 24 located between the connection position of the bypass line 27 and the catalyst cylinder 21. When the valve 26 is opened, the hydrogen sulfide generated in the catalyst cylinder 21 is supplied to the flow rate adjusting unit 31, and when the valve 26 is closed, the supply of hydrogen sulfide to the flow rate adjusting unit 31 is stopped.

The bypass line 27 is a line branched from the carbonyl sulfide supply line 14 located between the purification cylinder 13 and the valve 16, and the first hydrogen sulfide supply line 24 located between the valve 26 and the flow rate adjusting unit 31. Connected with.
The bypass line 27 is a line for bypassing the valves 16 and 26, the moisture addition unit 17, and the catalyst cylinder 21.

The valve 28 is provided in the bypass line 27. When the valve 28 is opened and the valves 16 and 26 are closed, the gas introduced into the sample gas supply line 11 is part of the carbonyl sulfide supply line 14, the bypass line 27, and the first hydrogen sulfide supply line 24. Is supplied to the flow rate adjusting unit 31.
When acquiring data necessary for calculating the conversion efficiency A, which will be described later, and when performing a process for measuring the concentration of carbonyl sulfide contained in the sample gas, the valve 28 is closed.

The flow rate adjusting unit 31 is connected to the other end of the first hydrogen sulfide supply line 24 and to one end of the second hydrogen sulfide supply line 33. The flow rate adjusting unit 31 performs adjustment so that the hydrogen sulfide supplied to the hydrogen sulfide concentration measuring device 34 has a predetermined flow rate.
Specifically, when the temperature of hydrogen sulfide derived from the first hydrogen sulfide supply line 24 is 85 degrees and the base gas constituting the sample gas is nitrogen, hydrogen sulfide supplied to the hydrogen sulfide concentration measuring device 34 The flow rate of can be 400 cc / min, for example.
Thus, by having the flow rate adjusting unit 31 that adjusts the flow rate of the hydrogen sulfide supplied to the hydrogen sulfide concentration measuring device 34, it becomes possible to set an optimal flow rate according to the gas type of the base gas. When the gas type of the base gas is changed, the flow rate of hydrogen sulfide can be adjusted so that the conversion efficiency A described later becomes the highest efficiency.
The flow rate adjusting unit 31 can be arranged on either the upstream side or the downstream side of the hydrogen sulfide concentration measuring device 34.

  One end of the second hydrogen sulfide supply line 33 is connected to the flow rate adjusting unit 31, and the other end is connected to the hydrogen sulfide concentration measuring device 34. The second hydrogen sulfide supply line 33 is a line for supplying hydrogen sulfide adjusted to a predetermined flow rate by the flow rate adjusting unit 31 to the hydrogen sulfide concentration measuring device 34.

The hydrogen sulfide concentration measuring device 34 continuously measures the concentration of hydrogen sulfide continuously supplied via the second hydrogen sulfide supply line 33 and supplies the measured data related to hydrogen sulfide to the control device 37 in real time. Send.
As the hydrogen sulfide concentration measuring device 34, for example, a commercially available hydrogen sulfide concentration meter can be used.

  One end of the exhaust line 36 is connected to the hydrogen sulfide concentration measuring device 34. The exhaust line 36 is a line for exhausting hydrogen sulfide derived from the hydrogen sulfide concentration measuring device 34.

  The control device 37 is a device that performs overall control of the carbonyl sulfide concentration measuring device 10, and is electrically connected to the power source 23-2, the flow rate adjusting unit 31, the hydrogen sulfide concentration measuring device 34, and the like. The control device 37 includes a storage unit 41, a calculation unit 42, a display unit 43, and a speaker 44.

  The storage unit 41 includes a program for driving the carbonyl sulfide concentration measuring device 10 and the temperature of the catalyst cylinder 21 heated by the heating unit 23 (for example, a predetermined temperature in the range of 60 to 120 degrees (for example, 85 degrees)). ), Data related to a predetermined flow rate of hydrogen sulfide adjusted by the flow rate control unit 31, hydrogen sulfide contained in a standard gas derived from the catalyst tube 21 at a predetermined temperature is supplied to the catalyst tube 21, and the flow rate Data relating to conversion efficiency (hereinafter referred to as “conversion efficiency A”) when hydrogen sulfide having a predetermined flow rate is supplied to the hydrogen sulfide concentration measuring device 34 by the adjusting unit 31 (at the time of hydrolysis when generating hydrogen sulfide) ( Data obtained by repeating the test in advance using a standard gas with known carbonyl sulfide) and the carbonyl sulfide concentration (described later) contained in the sample gas calculated by the calculation unit 42. And a threshold of carbonyl sulfide concentration E), and a voice message to recognize the operator that the sulfuric carbonyl concentration E is a dangerous state flowing when exceeding the threshold value, is stored.

Here, “conversion efficiency A” refers to the concentration of carbonyl sulfide (hereinafter referred to as “carbonyl sulfide concentration B”) contained in the standard gas (the gas whose carbonyl sulfide concentration is known), and the hydrogen sulfide concentration measuring device 34. Means the concentration (%) obtained from the concentration of hydrogen sulfide to be measured (hereinafter referred to as “hydrogen sulfide concentration C”).
The conversion efficiency A can be calculated by the following equation (1).
Conversion efficiency A (%) = 100 × (hydrogen sulfide concentration C / carbonyl sulfide concentration B) (1)
Specifically, for example, when the carbonyl sulfide concentration B is 10 ppm and the hydrogen sulfide concentration C is 6 ppm, the conversion efficiency A is 60% from the following equation (1).

The conversion efficiency A is preferably obtained using several standard gases having different values of the carbonyl sulfide concentration B.
In this case, for example, as shown in FIG. 2 to be described later, the horizontal axis is a known carbonyl sulfide concentration B (ppm), and the vertical axis is a hydrogen sulfide concentration C (ppm) measured by the hydrogen sulfide concentration measuring device 34, The hydrogen sulfide concentration C (ppm) contained in the standard gas is plotted.
Thereafter, based on the plotted points shown in FIG. 2, the linear approximation curve L is drawn, the slope of the linear approximation curve L is obtained, and the value of the slope is multiplied by 100 to obtain the conversion efficiency A (%). Can do.

  Based on the data on the temperature of the catalyst cylinder 21 stored in the storage unit 41 and the data on the predetermined flow rate of hydrogen sulfide adjusted by the flow rate adjustment unit 31, the calculation unit 42 supplies hydrogen sulfide to the hydrogen sulfide concentration measuring device 34. Hydrogen sulfide measured by the hydrogen sulfide concentration meter 34 when supplied (the concentration of hydrogen sulfide obtained by hydrolyzing carbonyl sulfide whose concentration is unknown in the sample gas (hereinafter referred to as “hydrogen sulfide concentration D”) And the conversion efficiency A stored in the storage unit 41, the measured concentration of carbonyl sulfide contained in the sample gas (hereinafter referred to as “carbonyl sulfide concentration E”) is calculated.

The computing unit 42 calculates the measured carbonyl sulfide concentration E (measured carbonyl sulfide concentration based on the measured hydrogen sulfide concentration D and the conversion efficiency A) contained in the sample gas by the following equation (2). .
Measured carbonyl sulfide concentration E = (100 / conversion efficiency A) × hydrogen sulfide concentration D (2)
Specifically, for example, when the conversion efficiency A is 60% and the hydrogen sulfide concentration D is 6 (ppm), the measured carbonyl sulfide concentration E is 10 (ppm) from the above equation (2).

The display unit 43 is a part that displays an image. The display unit 43 continuously displays the carbonyl sulfide concentration E calculated by the calculation unit 42 in real time.
For example, when the carbonyl sulfide concentration measuring apparatus 10 measures the concentration of carbonyl sulfide contained in the air (for example, in the air located around the semiconductor manufacturing apparatus), the speaker 44 measures the measured carbonyl sulfide concentration E. When the threshold stored in the storage unit 41 is exceeded, a voice message for letting the operator recognize that the state is dangerous is played.
For example, a personal computer can be used as the control device 37 configured as described above.

  According to the carbonyl sulfide concentration measuring apparatus of the present embodiment, a component other than carbonyl sulfide contained in the sample gas (or in the air) is adsorbed, and the purified cylinder 13 that allows the carbonyl sulfide to pass through, and the purified cylinder 13 pass through. Catalyst cylinder 21 for generating hydrogen sulfide from the produced carbonyl sulfide, a hydrogen sulfide concentration measuring device 34 for measuring the concentration of hydrogen sulfide generated in the catalyst cylinder 21, and a concentration of hydrogen sulfide measured by the hydrogen sulfide concentration measuring device 34 In the catalyst cylinder 21, the ratio of carbonyl sulfide having a known concentration contained in the standard gas is converted to hydrogen sulfide, and the conversion efficiency A acquired in advance, and the carbonyl sulfide contained in the sample gas By having the calculation unit 42 that calculates the concentration, it is not possible to directly measure the concentration of carbonyl sulfide that is difficult to measure continuously with high accuracy. The concentration of hydrogen sulfide produced from carbonyl fluoride and accurately and easily measured can be measured, and the concentration of hydrogen sulfide (hydrogen sulfide concentration D) measured by the hydrogen sulfide concentration measuring device 34 is obtained in advance. By measuring the concentration of carbonyl sulfide contained in the sample gas (carbonyl sulfide concentration E) based on the converted conversion efficiency A, the concentration of carbonyl sulfide contained in the gas containing air can be accurately and continuously determined. Can be measured.

  Next, the carbonyl sulfide concentration measuring method of the present embodiment using the carbonyl sulfide concentration measuring apparatus 10 shown in FIG. 1 will be described with reference to FIG. Here, a case where a sample gas containing carbonyl sulfide is caused to flow through the sample gas supply line 11 will be described as an example.

First, before performing the carbonyl sulfide acquisition step described later, the conversion efficiency A is acquired using the carbonyl sulfide concentration measuring device 10 shown in FIG. 1 and a standard gas containing carbonyl sulfide having a known concentration (conversion efficiency acquisition). Process).
Specifically, in the conversion efficiency acquisition step, a carbonyl sulfide acquisition step, a hydrogen sulfide generation step, and a hydrogen sulfide concentration measurement step, which will be described later, are performed using a sample gas containing carbonyl sulfide having an unknown concentration in the carbonyl sulfide concentration measurement device 10. The conversion efficiency A is acquired using the same processing conditions as in FIG. The acquired conversion efficiency A is stored in the storage unit 41 of the control device 37.
Here, the “same processing conditions” include, for example, the temperature at which the catalyst 21-2 constituting the catalyst cylinder 21 is heated, the flow rate of hydrogen sulfide supplied from the flow rate adjusting unit 31 to the hydrogen sulfide concentration measuring device 34, and the like. Say that it is the same condition.

The conversion efficiency A varies depending on conditions such as the temperature at which the catalyst 21-2 constituting the catalyst cylinder 21 is heated and the flow rate of hydrogen sulfide supplied from the flow rate adjusting unit 31 to the hydrogen sulfide concentration measuring device 34.
For this reason, as described above, the same processing conditions as the carbonyl sulfide acquisition step, the hydrogen sulfide generation step, and the hydrogen sulfide concentration measurement step performed using the sample gas containing the carbonyl sulfide whose concentration is unknown in the carbonyl sulfide concentration measurement device 10 Is used to obtain the conversion efficiency A, and in the carbonyl sulfide concentration measurement step for measuring the concentration of carbonyl sulfide described later, the exact concentration of carbonyl sulfide contained in the sample gas can be measured.

Next, with the valves 16 and 26 opened and the valve 28 closed, a sample gas containing carbonyl sulfide having an unknown concentration is supplied to the sample gas supply line 11. The sample gas is supplied to the aluminosilicate zeolite 13-2 in the purification cylinder 13 via the sample gas supply line 11.
Next, in the purification cylinder 13, components other than carbonyl sulfide contained in the sample gas are adsorbed by the aluminosilicate zeolite 13-2, and carbonyl sulfide contained in the sample gas is selectively led to the carbonyl sulfide supply line 14 ( Carbonyl sulfide acquisition process).
At this time, moisture contained in the sample gas is also removed.

  Here, the case where aluminosilicate zeolite 13-2 is used as an example of the adsorbent constituting the purification cylinder 13 has been described as an example, but components other than carbonyl sulfide contained in the sample gas can be adsorbed. It is not limited to the aluminosilicate zeolite 13-2.

The carbonyl sulfide led out to the carbonyl sulfide supply line 14 is supplied to the moisture addition unit 17 through the valve 16 through the carbonyl sulfide supply line 14.
In the water addition unit 17, water necessary for the hydrolysis reaction performed in the catalyst cylinder 21 is added to the carbonyl sulfide (water addition step).
In the moisture addition unit 17, for example, moisture is added to an amount such that the moisture concentration of carbonyl sulfide containing moisture led out to the moisture-containing carbonyl sulfide supply line 19 becomes a predetermined concentration within the range of 1 to 100 ppm.

  The carbonyl sulfide to which moisture has been added is led out to the moisture-containing carbonyl sulfide supply line 19 and then supplied to the catalyst 21-2 constituting the catalyst cylinder 21 via the moisture-containing carbonyl sulfide supply line 19.

Next, in the catalyst cylinder 21 heated at a predetermined temperature (for example, 85 degrees) in the temperature range of 60 to 120 degrees by the heating unit 23, hydrogen sulfide is converted from carbonyl sulfide by a hydrolysis reaction using the catalyst 21-2. (Hydrogen sulfide generation step).
In the hydrogen sulfide generation step, not all carbonyl sulfide is converted to hydrogen sulfide, but a part of hydrogen sulfide is converted to hydrogen sulfide.
Thus, by having the heating part 23 heated so that the temperature of the catalyst cylinder 21 (specifically, the catalyst 21-2) is within a range of 60 to 120 degrees (preferably 85 degrees), sulfurization is performed. The hydrolysis reaction at the time of producing hydrogen can be promoted.

The hydrogen sulfide generated in the catalyst cylinder 21-2 is supplied to the flow rate adjusting unit 31 via the first hydrogen sulfide supply line 24.
Next, the flow rate adjusting unit 31 adjusts the concentration of hydrogen sulfide supplied to the hydrogen sulfide concentration measuring device 34 so that it becomes a predetermined flow rate.
The predetermined flow rate (flow rate of hydrogen sulfide) can be appropriately set within a range of 100 to 1000 cc / min, for example.

The hydrogen sulfide concentration measuring device 34 is supplied with hydrogen sulfide adjusted to a predetermined flow rate by the flow rate adjusting unit 31 via the second hydrogen sulfide supply line 33.
The hydrogen sulfide concentration measuring device 34 continuously measures the concentration of hydrogen sulfide. Data relating to the concentration of hydrogen sulfide continuously measured by the hydrogen sulfide concentration measuring device 34 is transmitted to the control device 37 in real time.

The calculation unit 42 of the control device 37 performs calculation (specifically, the first step) based on the hydrogen sulfide concentration (hydrogen sulfide concentration C) measured in the hydrogen sulfide concentration measurement step and the conversion efficiency A acquired in advance. The carbonyl sulfide concentration contained in the sample gas is measured (calculation using the equation (2) described above in (1)) (carbonyl sulfide concentration measurement step).
The carbonyl sulfide concentration E obtained by the calculation unit 42 is displayed on the display unit 43 in real time.
When the measured carbonyl sulfide concentration E exceeds the threshold value stored in the storage unit 41, a voice message for letting the operator recognize that it is in a dangerous state is sent.

According to the carbonyl sulfide concentration measuring method of the present embodiment, carbonyl sulfide is obtained from carbonyl sulfide by a carbonyl sulfide obtaining step for selectively obtaining carbonyl sulfide contained in the sample gas and a hydrolysis reaction using catalyst 21-2. A hydrogen sulfide production step for producing hydrogen sulfide, a hydrogen sulfide concentration measurement step for measuring the concentration of hydrogen sulfide, a hydrogen sulfide concentration D measured in the hydrogen sulfide concentration measurement step, and a carbonyl sulfide with a known concentration contained in the standard gas. A carbonyl sulfide concentration measuring step of measuring the concentration of carbonyl sulfide contained in the sample gas by calculation based on the conversion efficiency A obtained in advance and the conversion efficiency A that is converted into hydrogen sulfide, Instead of directly measuring the concentration of carbonyl sulfide, which is difficult to measure accurately and accurately, hydrogen sulfide is generated from carbonyl sulfide. The concentration of hydrogen sulfide that can be measured continuously with high accuracy is measured and included in the sample gas based on the hydrogen sulfide concentration D measured by the hydrogen sulfide concentration meter 34 and the conversion efficiency A. It becomes possible to measure (calculate) the carbonyl sulfide concentration E continuously and accurately.
As a result, the carbonyl sulfide concentration E contained in the gas containing air can be measured continuously and accurately.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and within the scope of the present invention described in the claims, Various modifications and changes are possible.

  Hereinafter, although a test example is demonstrated, this invention is not limited to the following test example.

(Test Example 1)
First, the configuration and test conditions of the carbonyl sulfide concentration measuring apparatus 10 shown in FIG. 1 used in Test Example 1 will be described.
In Test Example 1, a cylindrical tubular member made of stainless steel having an inner diameter of ½ inch (= 12.7 mm) and a length of 120 mm was used as the cylinder main body 13-1. As the aluminosilicate zeolite 13-2, Molecular Sieve 3A (product name) manufactured by GL Sciences Inc. was used.

A Teflon (registered trademark) tube having an inner diameter of 4 mm was used as the moisture addition unit 17. As the cylindrical member 21-1, a stainless cylindrical member having an inner diameter of 1/2 inch (= 12.7 mm) and a length of 120 mm was used. As the catalyst 21-2, an alumina granule having a cylindrical shape, a diameter of 1 mm, and a length of 3 mm was used.
The temperature at which the heating unit 23 heats the catalyst 21-2 was 85 degrees. As the flow control unit 31, SEC-4400M (model number), which is a mass flow meter manufactured by HORIBA STEC Co., Ltd., was used. The flow rate of hydrogen sulfide supplied from the flow rate adjusting unit 31 to the hydrogen sulfide concentration measuring device 34 was 400 cc / min.
As the hydrogen sulfide concentration measuring device 34, SC-8000 (model number) which is a portable gas monitor manufactured by Riken Keiki Co., Ltd. was used.

Next, standard gases G1 to G6 containing carbonyl sulfide having a known concentration used in Test Example 1 will be described.
As the standard gas G1, a gas not containing carbonyl sulfide (that is, a gas having a carbonyl sulfide concentration of 0 ppm) was used. As the standard gas G2, a gas having a carbonyl sulfide concentration of 5 ppm was used. As the standard gas G3, a gas having a carbonyl sulfide concentration of 10 ppm was used.
As the standard gas G4, a gas having a carbonyl sulfide concentration of 15 ppm was used. As the standard gas G5, a gas having a carbonyl sulfide concentration of 20 ppm was used. As the standard gas G6, a gas having a carbonyl sulfide concentration of 25 ppm was used.

  In Test Example 1, the hydrogen sulfide concentration D was measured using the carbonyl sulfide concentration measuring device 10 shown in FIG. 1 described above, the test conditions, and the six standard gases G1 to G6. The results are shown in Table 1. Table 1 shows the known carbonyl sulfide concentration contained in the standard gases G1 to G6 used in Test Example 1, and the hydrogen sulfide concentration measured by the hydrogen sulfide concentration measuring instrument when using the standard gases G1 to G6. ing.

As shown in Table 1, the concentration of hydrogen sulfide when using standard gas G1 is 0 ppm, the concentration of hydrogen sulfide when using standard gas G2 is 3.0 ppm, and the concentration of hydrogen sulfide when using standard gas G3 The concentration is 5.2 ppm, the concentration of hydrogen sulfide when using the standard gas G4 is 9.7 ppm,
The concentration of hydrogen sulfide when the standard gas G5 was used was 11.5 ppm, and the concentration of hydrogen sulfide when the standard gas G5 was used was 14.8 ppm.

  FIG. 2 is a graph showing the relationship between the concentration of known carbonyl sulfide contained in the standard gases G1 to G6 and the concentration of hydrogen sulfide produced by hydrolyzing the carbonyl sulfide contained in the standard gases G1 to G6. It is.

Thereafter, the relationship between the concentration of known carbonyl sulfide contained in the standard gases G1 to G6 shown in Table 1 and the concentration of hydrogen sulfide produced by hydrolyzing the carbonyl sulfide contained in the standard gases G1 to G6 ( By graphing the measurement results shown in FIG. 2, the graph shown in FIG. 2 (the horizontal axis is the known carbonyl sulfide concentration, and the vertical axis is the measured hydrogen sulfide concentration) is created. Created.
Next, the slope of the linear approximation curve L shown in FIG. Therefore, by multiplying the value of the slope of the linear approximation curve L (in this case, 0.6) by 100, the conversion efficiency A was 60 (%).

As shown in FIG. 2, it was confirmed that the conversion efficiency A obtained by the above method is effective in the present case when the concentration of carbonyl sulfide is in the range of 0 ppm to 25 ppm.
Further, from the results shown in Table 1, for example, it is confirmed that the carbonyl sulfide concentration E contained in the sample gas can be accurately measured even when the sample gas contains carbonyl sulfide at a concentration of 5 ppm (low concentration). did it.

(Test Example 2)
FIG. 3 is an apparatus for evaluating a refined cylinder for confirming the effect of the refined cylinder used in Test Example 2. 3, the same components as those in the carbonyl sulfide concentration measuring apparatus 10 shown in FIG.

  First, referring to FIG. 3, the refinement cylinder evaluation device 50 used in Test Example 2 includes a refinement cylinder 13 and a flow rate control unit that constitute the carbonyl sulfide concentration measurement device 10 used in Test Example 1 described above. 31, an exhaust line 36, a standard gas introduction line 51, a standard gas supply line 53, valves 54, 57, 61, a gas chromatograph 55, a carbonyl sulfide supply line 56, and a bypass line 59.

The standard gas introduction line 51 is connected to one end of the flow rate adjusting unit 31. The standard gas introduction line 51 is a line for supplying standard gas to the flow rate adjusting unit 31.
One end of the standard gas supply line 53 is connected to the flow rate adjusting unit 31, and the other end is connected to one end of the purification cylinder 13. The standard gas supply line 53 supplies a standard gas, which has been set to a predetermined flow rate by the flow rate adjusting unit 31 (in Test Example 2, the flow rates of standard gases H1 to H6 described later are set to 500 ccm) to the purification cylinder 13.

The valve 54 is provided in the standard gas supply line 53 located between the branch position of the bypass line 59 and the purification cylinder 13. When the valve 54 is opened, standard gas is supplied via the standard gas supply line 53.
One end of the carbonyl sulfide supply line 56 is connected to the other end of the purification cylinder 13, and the other end is connected to the gas chromatograph 55. Carbonyl sulfide contained in the standard gas is led out to the carbonyl sulfide supply line 56. The derived carbonyl sulfide is supplied to the gas chromatograph 55 via the carbonyl sulfide supply line 56.

The valve 57 is provided in the carbonyl sulfide supply line 56 located between the connection position of the bypass line 59 and the purification cylinder 13.
The bypass line 59 is a line branched from the standard gas supply line 53 and is connected to the carbonyl sulfide supply line 56. The valve 61 is provided in the bypass line 59.
When the valve 61 is opened while the valves 54 and 57 are closed, the standard gas having a predetermined flow rate is supplied to the gas chromatograph 55 without passing through the purification cylinder 13.
The gas chromatograph 55 is an apparatus for measuring a sulfur compound contained in a sample gas, and GC6890 (model number) manufactured by Agilent Technologies, Inc., which does not have a column separation structure, was used.

In Test Example 2, six standard gases H1 to H6 were used. Specifically, as the standard gas H1, a base gas containing N ₂ and containing 5 ppm of H ₂ S (hydrogen sulfide) was used. As standard gas H2, the base gas in _{N 2,} was used containing 5ppm of SO ₂ (sulfur dioxide).
As the standard gas H3, a base gas containing N ₂ and containing 5 ppm of COS (carbonyl sulfide) was used. As the standard gas H4, a base gas containing N ₂ and containing 5 ppm of CH ₃ SH (methanethiol) was used.
As the standard gas H5, a base gas containing N ₂ and containing 5 ppm of DMS (dimethyl sulfide) was used. As the standard gas H6, a base gas containing N ₂ and containing 1 ppm DMDS (dimethyl disulfide) was used.

Next, the description and purified tube evaluation apparatus 50, the test conditions, and using a standard gas H1, upon carrying out a non-purified H 2 _S, and purification of H 2 _S, the output from a gas chromatograph 55 The voltage intensity (μV) of H ₂ S to be obtained was obtained. The result is shown in FIG.
When H ₂ S was not purified, the valve 61 was opened with the valves 54 and 57 closed, and when H ₂ S was purified, the valve 61 was closed with the valves 54 and 57 opened.

FIG. 4 is a diagram showing the voltage intensity (Output) of H ₂ S (hydrogen sulfide) contained in the standard gas H1 when H ₂ S is not purified and when H ₂ S is purified. In FIG. 4, the horizontal axis represents elapsed time, and the vertical axis represents the H ₂ S voltage intensity (Output).

Next, when the non-purification of SO _{2 and} the purification of SO ₂ are performed using the apparatus 50 for evaluating a purification cylinder described above, the above test conditions, and the standard gas H ₂ , the gas is output from the gas chromatograph 55. The voltage strength (μV) of SO ₂ was obtained. The result is shown in FIG.

FIG. 5 is a diagram showing the voltage intensity (Output) of SO ₂ S (sulfur dioxide) contained in the standard gas H2 when SO ₂ is not purified and when SO ₂ is purified. In FIG. 5, the horizontal axis represents elapsed time, and the vertical axis represents SO ₂ voltage intensity (Output).

  Next, the COS output from the gas chromatograph 55 when the non-purification of COS and the purification of COS are performed using the apparatus 50 for evaluating a purification cylinder described above, the test conditions, and the standard gas H3. The voltage intensity (μV) was obtained. The result is shown in FIG.

  FIG. 6 is a diagram showing the voltage intensity (Output) of COS (sulfur dioxide) contained in the standard gas H3 when COS is not purified and when COS is purified. In FIG. 6, the horizontal axis represents elapsed time, and the vertical axis represents COS voltage intensity (Output).

Next, output from the gas chromatograph 55 is performed when CH ₃ SH is not purified and CH ₃ SH is purified using the purification cylinder evaluation apparatus 50 described above, the above test conditions, and the standard gas H4. The output (μV) of the voltage intensity of CH ₃ SH to be obtained was obtained. The result is shown in FIG.

FIG. 7 is a diagram showing the voltage intensity (Output) of CH ₃ SH (methanethiol) contained in the standard gas H4 when CH ₃ SH is not purified and when CH ₃ SH is purified. In FIG. 7, the horizontal axis represents elapsed time, and the vertical axis represents the CH ₃ SH voltage intensity (Output).

  Next, the DMS output from the gas chromatograph 55 when the DMS non-purification and the DMS purification are performed using the apparatus 50 for evaluation of the purification cylinder described above, the test conditions, and the standard gas H5. The voltage intensity (μV) was obtained. The result is shown in FIG.

  FIG. 8 is a diagram showing the voltage intensity (Output) of DMS (dimethyl sulfide) contained in the standard gas H5 when DMS is not purified and when DMS is purified. In FIG. 8, the horizontal axis represents elapsed time, and the vertical axis represents DMS voltage intensity (Output).

  Next, the DMDS output from the gas chromatograph 55 when the non-purification of DMDS and the purification of DMDS are performed using the apparatus 50 for purification cylinder evaluation described above, the above test conditions, and the standard gas H6. The voltage intensity (μV) was obtained. The result is shown in FIG.

  FIG. 9 is a diagram showing the voltage intensity (Output) of DMDS (dimethyl disulfide) contained in the standard gas H6 when DMDS is not purified and when DMDS is purified. In FIG. 9, the horizontal axis represents elapsed time, and the vertical axis represents DMDS voltage intensity (Output).

Referring to FIG. 4, H ₂ S was not detected during the H ₂ S purification period (in other words, when the standard gas H1 passes through the purification cylinder 13).
Referring to FIG. 5, SO ₂ was not detected during the SO ₂ purification period (in other words, when standard gas H 2 passes through purification cylinder 13).
Referring to FIG. 6, in the COS purification period (in other words, when the standard gas H3 passes through the purification cylinder 13), COS having the same intensity was detected during the COS non-purification period.
Referring to FIG. 7, CH ₃ SH was not detected during the CH ₃ SH purification period (in other words, when the standard gas H4 passes through the purification cylinder 13).
Referring to FIG. 8, DMS was not detected during the DMS purification period (in other words, when the standard gas H5 passes through the purification cylinder 13).
Referring to FIG. 9, DMDS was not detected during the DMDS purification period (in other words, when the standard gas H6 passes through the purification cylinder 13).
From these results, H ₂ S, SO ₂ , CH ₃ SH, DMS, and DMDS are adsorbed by using Molecular Sieve 3A (product name) manufactured by GL Sciences Inc. as aluminosilicate zeolite 13-2. It was confirmed that COS (hydrogen sulfide) can be selectively passed.

  The present invention is applicable to a carbonyl sulfide concentration measuring apparatus and a carbonyl sulfide concentration measuring method capable of measuring the concentration of carbonyl sulfide contained in a gas containing air continuously and accurately.

  DESCRIPTION OF SYMBOLS 10 ... Carbon sulfide concentration measuring apparatus, 11 ... Sample gas supply line, 13 ... Refinement | purification cylinder, 13-1 ... Cylinder body, 13-2 ... Aluminosilicate zeolite, 14 ... Carbonyl sulfide supply line, 16, 26, 28, 54 , 57, 61 ... valve, 17 ... moisture addition section, 19 ... moisture-containing carbonyl sulfide supply line, 21 ... catalyst cylinder, 21-1 ... cylindrical member, 21-2 ... catalyst, 23 ... heating section, 23-1 ... Hot wire, 23-2 ... Power source, 24 ... First hydrogen sulfide supply line, 27, 59 ... Bypass line, 31 ... Flow rate adjusting unit, 33 ... Second hydrogen sulfide supply line, 34 ... Hydrogen sulfide concentration measuring device, 36 DESCRIPTION OF SYMBOLS ... Exhaust line, 37 ... Control apparatus, 41 ... Memory | storage part, 42 ... Calculation part, 43 ... Display part, 44 ... Speaker, 50 ... Refinement cylinder evaluation apparatus, 51 ... Standard gas introduction line, 53 ... Standard gas supply line, 5 ... gas chromatograph, 56 ... carbonyl sulfide feed line

Claims (9)

A purification cylinder that adsorbs components other than carbonyl sulfide contained in the sample gas and passes the carbonyl sulfide;
A catalyst cylinder that generates hydrogen sulfide from the carbonyl sulfide that has passed through the purification cylinder by a hydrolysis reaction;
A hydrogen sulfide concentration measuring device for measuring the concentration of the hydrogen sulfide produced in the catalyst cylinder;
The hydrogen sulfide concentration measured by the hydrogen sulfide concentration measuring device and the ratio in which the carbonyl sulfide having a known concentration contained in the standard gas is converted into hydrogen sulfide in the catalyst cylinder, and the conversion efficiency obtained in advance. And a calculation unit for calculating the concentration of the carbonyl sulfide contained in the sample gas based on
A carbonyl sulfide concentration measuring device characterized by comprising: The purification cylinder includes a cylinder body,
An aluminosilicate zeolite filled in the cylinder body;
The carbonyl sulfide concentration measuring apparatus according to claim 1, wherein   3. The carbonyl sulfide concentration measurement according to claim 1, further comprising a moisture addition unit that adds moisture to the carbonyl sulfide that has passed through the purification cylinder and supplies the carbonyl sulfide containing the moisture to the catalyst cylinder. apparatus.   4. The apparatus according to claim 1, further comprising a flow rate adjusting unit that is arranged upstream or downstream of the hydrogen sulfide concentration measuring device and adjusts a flow rate of the hydrogen sulfide supplied to the hydrogen sulfide concentration measuring device. The carbonyl sulfide concentration measuring apparatus according to any one of the above. A carbonyl sulfide acquisition step of selectively acquiring carbonyl sulfide contained in the sample gas;
A hydrogen sulfide generation step of generating hydrogen sulfide from the carbonyl sulfide by a hydrolysis reaction using a catalyst;
A hydrogen sulfide concentration measuring step for measuring the concentration of the hydrogen sulfide;
Based on the hydrogen sulfide concentration measured in the hydrogen sulfide concentration measurement step, the rate at which the carbonyl sulfide having a known concentration contained in the standard gas is converted to hydrogen sulfide, and the conversion efficiency obtained in advance. , A carbonyl sulfide concentration measuring step for measuring the concentration of the carbonyl sulfide contained in the sample gas by calculation,
A carbonyl sulfide concentration measuring method characterized by comprising:   6. The carbonyl sulfide concentration measuring method according to claim 5, wherein an aluminosilicate zeolite is used in the carbonyl sulfide obtaining step.   The carbonyl sulfide concentration measuring method according to claim 5 or 6, further comprising a moisture addition step of adding moisture to the carbonyl sulfide between the carbonyl sulfide acquisition step and the hydrogen sulfide generation step.   The carbonyl sulfide according to any one of claims 5 to 7, wherein the catalyst cylinder is heated so that the temperature of the catalyst cylinder becomes a predetermined temperature within a range of 60 degrees to 120 degrees. Concentration measurement method.   The carbonyl sulfide concentration measuring method according to any one of claims 5 to 8, wherein a flow rate of the hydrogen sulfide supplied to the hydrogen sulfide concentration measuring device is adjusted to be a predetermined flow rate.

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