JP2005300362A - Gas sample introduction device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein a pressurized carrier gas in a weighing tube is introduced into a vessel in each measurement, when the sample gas sealed in the vessel of a fixed volume is weighed repeatedly and introduced into a GC, and wherein a sample gas is thereby diluted to disturb the accurate measurement. <P>SOLUTION: Valves 5, 6 are provided to block respectively a supply flow passage F1 from the measuring vessel 1 to a ten-way valve 4, and a recovery flow passage F2 for return from the ten-way valve 4 to the measuring vessel 1, and the flow passage F2 between the flow passage F2 and the valve 6 is connected to a discharge port 10 via a valve 9. The valves 5, 6 are closed and the valve 9 is opened in advance to switching of the valve 4 from to a condition showed by a solid line to a condition showed by a dotted line, and the valve 4 is switched thereafter. The carrier gas more than required is prevented from flowing into the measuring vessel 1, when the valves 5, 6 are opened and when the valve 9 is closed, followed thereto, since the gas is discharged to the atmosphere until an inside of the weighing tube is brought substantially into the atmospheric pressure after the switching 11, although the pressurized carrier gas is remained in the weighing tube before the switching. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a gas sample introduction device for introducing a gas sample into a gas analyzer such as a gas chromatograph.

  In gas chromatographic analysis for a gas sample, a gas sample introduction device including a flow path switching valve and a metering tube is provided at the column inlet, and the sample gas is sampled so that a predetermined gas pressure is obtained in the metering tube. The collected sample gas is sent to the column. FIG. 7 is a schematic diagram showing a flow path configuration of a conventionally known gas chromatograph for gas sample analysis (see, for example, Patent Document 1).

  The six-way valve 52 which is a sampling valve can be switched between a connection state indicated by a solid line and a connection state indicated by a dotted line in FIG. 7 by manual force or mechanical force. In the connection state indicated by the dotted line, the carrier gas supplied to the carrier gas supply port 54 from a gas cylinder (not shown) or the like passes through the ports [2] and [1] of the six-way valve 52 and passes through the column 56 and the detector 57. Flow through. On the other hand, the sample gas supplied to the sample gas supply port 50 passes through the ports [3] and [6] of the six-way valve 52 via the electromagnetic on-off valve 51, passes through the measuring tube 55, and then enters the port [ It is discharged from the gas discharge port 53 via 5] and [4]. The process of flowing the sample gas through the measuring tube 55 in this way is generally called charging.

  After such charging, the six-way valve 52 is switched to a connection state indicated by a solid line in FIG. Then, the carrier gas that has been flowing in a short circuit in the six-way valve 52 until then passes through the measuring tube 55 in the opposite direction to the flow of the sample gas. Accordingly, a certain amount of sample gas determined by the internal volume of the measuring tube 55 remaining in the measuring tube 55 is pushed out to the carrier gas, and is sent to the column 56 via the ports [6] and [1] of the hexagonal valve 52. And flow into. Various components contained in the sample gas when passing through the column 56 are temporally separated, and are sequentially detected by the detector 57 as they leave the column 56. The operation of introducing a predetermined amount of the sample gas into the carrier gas flow is generally called sampling.

  When the sample gas held in the measuring tube 55 is completely sent to the column 56 and the hexagonal valve 52 is switched again to the connection state indicated by the dotted line, the sample gas flows into the measuring tube 55 as described above. The carrier gas remaining in the measuring tube 55 is pushed by the sample gas and discharged from the gas discharge port 53. In general, the gas outlet 53 is open to the atmosphere or connected to an exhaust gas tank. Usually, the carrier gas remaining in the measuring tube 55 is completely replaced by a sufficient volume of the sample gas.

  By the way, depending on the purpose of analysis, the sample gas discharged from the gas discharge port 53 during charging may be collected and used again for analysis. For example, when it is desired to obtain the concentration change by repeatedly measuring the concentration of the sample gas enclosed in the airtight container having a predetermined internal volume and approximately atmospheric pressure, as shown in FIG. A loop-shaped flow path including the airtight container 58 and the pump 59 is formed. That is, at the time of charging, the pump 59 is operated, the sample gas sucked from the inside of the airtight container 58 is passed through the measuring tube 55, and the passed sample gas is returned to the airtight container 58.

  In this configuration, the gas pressure of the carrier gas supplied to the carrier gas supply port 54 is high so that a constant flow rate of carrier gas flows through the column 56 due to the differential pressure. Therefore, the gas pressure in the measuring tube 55 is high at the time of sampling, and when the hexagonal valve 52 is switched from the state shown by the solid line to the state shown by the dotted line, the carrier that is temporarily pressurized in the measuring tube 55 Gas is retained. When the hexagonal valve 52 is switched to the state indicated by the dotted line, the gas pressure in the measuring tube 55 is higher than the gas pressure in the hermetic vessel 58, so that the carrier gas held in the measuring tube 55 is sealed by the differential pressure. 58 flows into. Therefore, gas components other than the target component increase by the amount of the pressurized carrier gas, and as a result, the sample gas is diluted. When the sample gas in the hermetic container 58 is repeatedly collected and analyzed by gas chromatography, the sample gas is diluted for each measurement, which hinders accurate concentration measurement.

JP 2001-165918 A

  The present invention has been made in view of the above points, and the object of the present invention is to charge such a sample gas even when, for example, a sample gas in an airtight container is collected and repeatedly measured. An object of the present invention is to provide a gas sample introduction device capable of preventing a sample gas from being diluted by a carrier gas in the process of sampling and sampling.

The present invention made to solve the above-mentioned problems is a gas sample introduction device for introducing a sample gas into a gas analysis section, and has a measuring tube with a predetermined internal volume, and holds the sample gas in the measuring tube Thus, the flow path is set in a charging state in which the sample gas flows through the measuring tube and a sampling state in which the carrier gas flows into the measuring tube so that the sample gas held in the measuring tube is pushed out and introduced into the gas analyzer. A sampling valve for switching, a sample gas supply channel for supplying a sample gas to the sampling valve in a charging state, and a sample gas recovery flow for recovering from the sampling valve the sample gas that has passed through the measuring tube in the charging state A gas sample introduction device comprising:
a) first channel opening / closing means provided on the sample gas supply channel;
b) a second channel opening / closing means provided on the sample gas recovery channel;
c) third flow path opening / closing means having one end connected to the sample gas recovery flow path between the second flow path opening / closing means and the sampling valve and the other end reaching the discharge port;
d) When the sampling valve is switched from the sampling state to the charging state, the first and second flow path opening / closing means are closed and the third flow path opening / closing means are opened prior to charging the sampling valve. Control for controlling the operation of each channel opening / closing means and the sampling valve so that the first and second channel opening / closing means are opened and the third channel opening / closing means are closed after a predetermined time has elapsed after switching to the state. Means,
It is characterized by having.

  In the gas sample introduction device according to the present invention, for example, the end portions of the sample gas supply channel and the sample gas recovery channel are connected to a measurement container having a predetermined internal volume, and the sample gas sealed in the measurement container is removed. It can utilize suitably for the structure which repeats the operation | movement which extract | collects to the said measuring tube and introduces into the said gas analysis part.

  In the gas sample introduction device according to the present invention, the control means basically opens the first and second flow path opening / closing means and closes the third flow path opening / closing means when charging. Thereby, for example, the sample gas supplied from the measurement container to the sampling valve through the sample gas supply flow path flows into the measuring tube, and is further recovered from the sampling valve to the measurement container through the sample gas recovery flow path. At this time, a certain amount of sample gas determined by the internal volume is held in the measuring tube. Next, when the sampling valve is switched to the sampling state, the carrier gas is supplied to the measuring tube in which the sample gas has been previously held, and the sample gas is pushed out by the carrier gas and is discharged from the measuring tube through the sampling valve. Introduced to the analysis department. As a result, the sample gas can be analyzed in the gas analyzer. At this time, for example, the sampling gas supply channel and the sample gas recovery channel are short-circuited by a sampling valve, and the carrier gas does not flow into the sample gas recovery channel.

  When switching the sampling valve from the sampling state to the charging state, the control means closes the first and second flow path opening / closing means and opens the third flow path opening / closing means prior to the switching operation. Thereby, the sample gas supply channel and the sample gas recovery channel are sealed between the first channel opening / closing means and the second channel opening / closing means with the sampling valve interposed therebetween. However, since the third channel opening / closing means is open, the channel blocked through this means communicates with the discharge port. For example, the discharge port is opened to the atmosphere so as to be at substantially atmospheric pressure.

  When the sampling valve is switched to the charging state in such a state of the flow path, the measuring tube is inserted into the blocked flow path. Immediately before the switching, a pressurized carrier gas (having a gas pressure higher than the atmospheric pressure) is held in the measuring tube, so that the pressure difference between the gas pressure in the measuring tube and the gas pressure at the discharge port The carrier gas held in the measuring tube flows through the sealed flow path toward the discharge port through the sampling valve. Then, the carrier gas is discharged from the discharge port, and the discharge of the carrier gas continues until the gas pressure in the measuring tube becomes the same as the gas pressure in the exhaust port. After a predetermined time has passed so that the carrier gas is sufficiently discharged, the control means switches to open the first and second flow path opening / closing means and closes the third flow path opening / closing means to perform actual charging. Start operation.

  Through the procedure as described above, the pressurized portion of the carrier gas remaining in a pressurized state in the measuring tube is discharged out of the flow path, so that the charging is started through the sample gas recovery flow path at the start of charging. What flows into the measurement container is a carrier gas that is substantially equivalent to the sample gas originally collected by the measuring tube. Therefore, dilution of the sample gas sealed in the measurement container can be avoided.

  In the gas sample introduction device according to the present invention, various types of gas analysis units are conceivable. Typically, separation is performed on the assumption that the components of the sample gas collected in a measuring tube having a small internal volume can be analyzed. And a gas chromatograph comprising a detector for detecting a sample component separated by the column.

  According to the gas sample introduction device of the present invention, the carrier gas held in the state where the measuring tube is pressurized in the process of charging and sampling of the sample gas passes through the sample gas recovery channel more than necessary and is measured. It is possible to prevent the sample gas in the measurement container from being diluted. Thereby, for example, analysis of any sample component in the sample gas in the measurement container, for example, measurement of the concentration can be performed stably and accurately. Therefore, for example, it is possible to measure the concentration change of an arbitrary component contained in the sample gas in the measurement container with high accuracy.

  An embodiment of a gas sample introduction device according to the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram centering on a flow path of a gas chromatograph using the gas sample introduction device of this embodiment.

  In FIG. 1, the sample gas outlet 1b of the measuring container 1 having a constant internal volume is connected to the port [4] of the six-way valve 3 which can be switched between two connection states indicated by a solid line and a dotted line. 2] is connected to a standard gas supply port 2 to which a standard gas for quantitative analysis for calibration is supplied. The 10-way valve 4 which is a sampling valve can also be switched between two connection states indicated by a solid line and a dotted line, and a precolumn (PC) 12 is connected between the port [2] and the port [6]. A measuring tube 11 having an internal volume of 4.5 mL is connected between [7] and port [10]. The flow path from the sample gas outlet 1b of the measurement container 1 to the port [9] of the ten-way valve 4 is a sample gas supply flow path F1, and the port [5] of the six-way valve 3 and the port of the ten-way valve 4 A first electromagnetic on-off valve 5 is provided in the sample gas supply flow path F1 between [9]. On the other hand, a flow path from the port [8] of the ten-way valve 4 to the sample gas inlet 1a of the measurement container 1 is a sample gas recovery flow path F2, and the flow of the sample gas is along the flow path F2. A second electromagnetic on-off valve 6, a pump 7, and a flow meter 8 are provided. Further, the flow path F2 between the port [8] of the ten-way valve 4 and the second electromagnetic on-off valve 6 is connected to a gas discharge port 10 opened to the atmosphere via the third electromagnetic on-off valve 9.

  The port [1] of the ten-way valve 4 is connected to the carrier gas supply port 17, and the port [4] of the ten-way valve 4 is connected to another carrier gas supply port 18 via a dummy column (DC) 14. . A carrier gas (for example, helium) serving as a mobile phase of the gas chromatograph is supplied to the carrier gas supply ports 17 and 18 at a gas pressure about twice the atmospheric pressure. The port [5] of the ten-way valve 4 reaches the choke vent (CC VENT) via the choke column (CC) 15, and the port [3] of the ten-way valve 4 has an inlet end of the main column (MC). The outlet end of the main column 13 is connected to a detector 16 which is a flame ionization detector (FID). The detection signal of the detector 16 is input to the data processing unit 21, and the data processing unit 21 executes various data processing based on the detection signal as will be described later.

  A control unit 20 is provided to control the opening / closing operation of the first, second, and third electromagnetic opening / closing valves 5, 6, 9, the switching operation of the ten-way valve 4, the six-way valve 3, and the operation of the pump 7. The control unit 20 is provided with an operation unit 22 having a keyboard and various switches and a display unit 23. The control unit 20 is embodied by a personal computer, for example, and performs charging and sampling of the sample gas by controlling the operation of each of the above units according to a predetermined control program. The data processing unit 21 can also be realized by the same personal computer, and a dedicated data processing device (for example, Chromatopack (registered trademark) manufactured by Shimadzu Corporation) can be used.

  The gas chromatograph having the above-described configuration is used, for example, for measuring the degree of gas leakage of a measurement object (for example, an air conditioner or a refrigerator) in which a specific gas is sealed. In such measurement, the measurement object S is accommodated in the measurement container 1, and atmospheric pressure air is sealed in the measurement container 1. When a specific gas (for example, chlorofluorocarbon) leaks from the measurement object S, the concentration of the specific gas in the air in the measurement container 1 gradually increases. Therefore, if the specific gas concentration in the air in the measurement container 1 is repeatedly measured over a certain period, the degree of gas leakage over a long period of time such as several years can be estimated from the result. When performing such a large number of repeated measurements, the apparatus of this embodiment collects a small amount of air (sample gas) in the measurement container 1 and performs gas chromatographic analysis. Perform the sampling operation. The sampling operation of the sample gas will be described below with reference to FIGS.

  First, the control unit 20 sets the hexagonal valve 3 to the connection state indicated by the solid line in FIG. 1, sets the ten-way valve 4 to the connection state indicated by the dotted line, opens the first and second electromagnetic opening / closing valves 5 and 6, and sets the third electromagnetic valve The on-off valve 9 is closed. In this state, the pump 7 sucks gas at a constant flow rate while monitoring the flow rate with the flow meter 8. FIG. 2 shows the flow path configuration at this time. At this time, as shown by a thick line in FIG. 2, the sample gas outlet 1b of the measuring vessel 1—the ports [4], [5] of the six-way valve 3—the first electromagnetic on-off valve 5—the port [9] of the ten-way valve 4 , [10] -metering pipe 11-port 10 of the 10-way valve 4 [7], [8] -second electromagnetic on-off valve 6-pump 7-flow meter 8-sample gas inlet 1a of the measuring vessel 1 A flow path is formed. That is, the measuring tube 11 is sandwiched between the sample gas supply flow path F1 and the sample gas recovery flow path F2, and the sample gas sucked by the pump 7 flows through the flow path, and the inside of the measuring tube 11 A fixed amount of sample gas determined by the internal volume is held. Such a process of holding the sample gas is charging. Since the sample gas in the measurement container 1 flows cyclically, the concentration of the sample gas in the measurement container 1 does not change at this time.

  The carrier gas supplied to the carrier gas supply port 17 flows to the pre-column 12 via the ports [1] and [2] of the ten-way valve 4 and further to the ports [6] and [5] of the ten-way valve 4. To the choke column 15 and discharged from the choke vent. On the other hand, the carrier gas supplied to the carrier gas supply port 18 passes through the ports [4] and [3] of the ten-way valve 4 via the dummy column 14, and further flows to the main column 13 and the detector 16. Thus, since the carrier gas flows through each of the columns 12, 13, 14, and 15, the inside of the column is not contaminated.

  After a predetermined time has elapsed since the start of charging as described above, the control unit 20 switches the ten-way valve 4 from the connection state indicated by the dotted line in FIG. 1 to the connection state indicated by the solid line. FIG. 3 shows the flow path configuration at this time. At this time, as shown by a thick line in FIG. 3, the carrier gas supply port 17—the ports [1], [10] of the ten-way valve 4—the measuring tube 11—the ports [7], [6] of the ten-way valve 4 -Pre-column 12-Ports [2] and [3] of the ten-way valve 4-Main column 13-Detector 16 are formed. As a result, the sample gas held in the measuring tube 11 immediately before is pushed by the carrier gas entering from the right side and flows in the order of the pre-column 12 and the main column 13. The components are separated and detected by the detector 16. The detection signal from the detector 16 is sent to the data processing unit 21. The data processing unit 21 creates a chromatogram based on the detection signals sequentially obtained as time elapses. For example, a specific gas is determined from the peak area appearing in the chromatogram. Predetermined arithmetic processing such as calculation of component concentrations is performed.

  At this time, the carrier gas supplied to the carrier gas supply port 18 passes through the dummy column 14 through the ports [4] and [5] of the ten-way valve 4 and flows into the choke column 15 and is discharged from the choke vent. Is done. Also, the sample gas outlet 1b of the measuring vessel 1-the ports [4], [5] of the hexagonal valve 3-the first electromagnetic on-off valve 5-the ports [9], [8] of the ten-way valve 4-the second electromagnetic on-off valve 6-pump 7—flow meter 8—sample gas inlet 1a of container 1, a loop-shaped flow path, that is, a flow path in which sample gas supply flow path F1 and sample gas recovery flow path F2 are short-circuited is formed, The sample gas flows cyclically in this flow path.

  At an appropriate timing after the time necessary for completely sending the sample gas held in the measuring tube 11 to the main column 13 has elapsed, the control unit 20 connects the ten-way valve 4 to the connection state indicated by the solid line in FIG. However, prior to this, the operation of the pump 7 is first stopped. Since the inside of the measurement container 1 is almost atmospheric pressure and there is no pressure difference between the sample gas outlet 1b and the sample gas inlet 1a, the circulation of the sample gas stops when the pump 7 is stopped. Next, the first and second electromagnetic on-off valves 5 and 6 are closed, and switching is performed so that the third electromagnetic on-off valve 9 is opened at the same time or a little later than that. FIG. 4 shows the flow path configuration at this time. At this time, as shown by a thick line in FIG. 4, both ends of the flow path between the first electromagnetic on-off valve 5 and the second electromagnetic on-off valve 6 sandwiching the ports [9], [8] of the ten-way valve 4 are sandwiched. Is closed, and this flow path communicates only with the gas discharge port 10 through the third electromagnetic on-off valve 9. What is particularly important here is that the sample gas supply flow path F1 and the sample gas recovery flow path F2 connected to the ports [9] and [8] of the ten-way valve 4 are completely disconnected from the measurement container 1, and instead. In addition, the port [8] of the ten-way valve 4 and the gas discharge port 10 are connected via the third electromagnetic opening / closing valve 9.

  In the state where the flow path is switched as described above, the ten-way valve 4 is switched to the connection state indicated by the dotted line in FIG. FIG. 5 shows the flow path configuration at this time. At this time, as shown by a thick line in FIG. 5, the measuring tube 11 is inserted into the flow path whose both ends are closed between the first electromagnetic on-off valve 5 and the second electromagnetic on-off valve 6 described above. Become. Immediately before the switching of the ten-way valve 4, the carrier gas flows through the measuring tube 11, and at this time, the gas pressure in the measuring tube 11 is substantially equal to the gas pressure in the carrier gas supply port 17. Assuming that the gas supply pressure to the carrier gas supply port 10 is twice the atmospheric pressure, the capacity of the carrier gas that can exist in the measuring tube 11 is twice the normal atmospheric pressure. That is, when the inner volume of the measuring tube 11 is 4.5 mL, the amount of carrier gas that can exist in the measuring tube 11 is a volume corresponding to 9 mL under atmospheric pressure.

  Thus, when the ten-way valve 4 is switched, the carrier gas is sealed in the measuring tube 11 at a gas pressure higher than the atmospheric pressure. On the other hand, when the ten-way valve 4 is switched and the flow path is formed, the gas discharge port 10 is at substantially atmospheric pressure. Therefore, a pressure difference is generated between the measuring tube 11 and the gas discharge port 10. Due to the pressure, the carrier gas in the measuring tube 11 flows in the flow path toward the gas outlet 10 and is finally released into the atmosphere. The discharge of the carrier gas continues until the inside of the measuring tube 11 becomes substantially atmospheric pressure and the gas pressure is balanced in the flow path. At the time when the release of the carrier gas from the gas discharge port 10 is completed, a carrier gas with a volume of 4.5 mL should remain in the measuring tube 11, and eventually the carrier with a volume of 4.5 mL that has been pressurized is used. Gas will decrease.

  After discharging the pressurized carrier gas from the metering tube 11 in this way, the control unit 20 opens the first and second electromagnetic release valves 5 and 6 again and closes the third electromagnetic release valve 9. Then, the pump 7 is operated. Accordingly, the flow path shown in FIG. 2 is formed again, and the sample gas sucked from the measurement container 1 flows into the measuring tube 11 to hold a certain amount of sample gas. At this time, the carrier gas remaining in the measuring tube 11 flows into the measuring container 1 as described above, and the capacity of the carrier gas is the same as that of the sample gas collected in the measuring tube 11 by charging. Thus, since the total gas capacity does not increase, the sample components in the measurement container 1 are not diluted.

  However, for each measurement, the sample gas in the measurement container 1 is replaced with the carrier gas by an amount corresponding to the internal volume of the measuring tube 11 (here, 4.5 mL). That is, the sample gas in the measurement container 1 is not diluted, but the specific gas component in the sample gas in the measurement container 1 is consumed and reduced by the amount contained in 4.5 mL of the sample gas. This is an unavoidable problem in this analysis because of the essential reason that the sample components are consumed (that is, cannot be refluxed) in the gas chromatographic analysis. Therefore, when the concentration of the specific gas component in the measurement container 1 is repeatedly measured, it is necessary to consider that the concentration decreases by an amount corresponding to the decrease in the sample gas for each measurement. Since the amount of decrease in the sample gas in each measurement is determined, it is relatively easy to calculate the concentration by correcting the concentration decrease as described above.

  When repeated measurement is performed with the configuration of the above-described embodiment, the conventional device (the first and second electromagnetic on-off valves 5 and 6 are always opened and the third electromagnetic on-off valve 9 is closed with the configuration shown in FIG. 1). FIG. 6 shows the experimental results of the stability of the concentration when the measurement is repeated in the state). In this experiment, a small amount of reference gas (for example, propane gas) was introduced into a sealed measurement vessel 1 from a reference gas introduction unit (not shown) before repeated measurement, and the concentration of the reference gas component was repeatedly measured. is there. The measurement is performed up to 19 times at regular time intervals, the peak area of the peak of the reference gas appearing on the chromatogram obtained for each measurement is obtained, and the concentration is calculated from the peak area.

  In the conventional apparatus, the sample gas is sampled from the measurement container 1 for each measurement and the reference gas component is decreased little by little, and the reference gas component is also diluted with the carrier gas. Therefore, as shown in FIG. In total, the reference gas concentration is reduced by about 4.6%. On the other hand, in the configuration of the present embodiment, since the reference gas component is not diluted by the carrier gas, the total decrease in the reference gas concentration is 2.0% as shown in FIG. It can be seen that it is reduced to less than half. As described above, when correction is performed by data processing in consideration of the reduction amount of the reference gas component consumed for each measurement, the result is as shown in FIG. Since the reduction amount of the consumed reference gas component can be grasped relatively accurately, the total concentration attenuation can be greatly reduced to about 0.4% by performing the correction process.

  As described above, according to the configuration of this embodiment, when the concentration of an arbitrary component of the sample gas in the measurement container 1 is repeatedly measured, it is possible to prevent the concentration from being attenuated more than necessary. The concentration of the component can be measured stably and accurately. Therefore, for example, when measuring gas leakage from the measurement object as described above, for example, it is possible to capture the fluctuation of the concentration of the specific gas component with high accuracy, and to improve the estimation accuracy of the degree of gas leakage. Can do.

  The configuration of the above embodiment is merely an example, and various modifications and additions can be made. For example, in the above embodiment, a ten-way valve is used as a sampling valve, but this may be a valve having an appropriate configuration. The insertion position of the pump 7 for sucking the sample gas from the measurement container 1 and returning it to the measurement container 1 and the flow meter 7 for measuring the flow rate are not limited to the above description. What is required is that the sample gas supply flow path F1 for supplying the sample gas from the measurement container 1 to the sampling valve and the sample gas recovery flow path F2 for returning the sample gas from the sampling valve to the measurement container 1 are electromagnetically opened and closed, respectively. In addition to providing flow path opening / closing means such as a valve, a discharge means for discharging gas in the flow path whose both ends can be blocked by the flow path opening / closing means is provided. In addition to these points, it is obvious that the invention of the present application is included even if appropriate changes, additions and modifications are made within the scope of the present invention.

The block diagram centering on the flow path of the gas chromatograph provided with the gas sample introduction apparatus by one Example of this invention. The flow-path block diagram for demonstrating sampling operation | movement of the sample gas in the gas chromatograph in a present Example. The flow-path block diagram for demonstrating sampling operation | movement of the sample gas in the gas chromatograph in a present Example. The flow-path block diagram for demonstrating sampling operation | movement of the sample gas in the gas chromatograph in a present Example. The flow-path block diagram for demonstrating sampling operation | movement of the sample gas in the gas chromatograph in a present Example. The figure which shows the experimental result for demonstrating the difference of the effect of the structure of a present Example, and a conventional apparatus. The flow-path block diagram of the gas chromatograph provided with the conventional gas sample introducing device. The flow-path block diagram in the case of measuring repeatedly the sample gas in an airtight container with the apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Measurement container 1a ... Sample gas inlet 1b ... Sample gas outlet 2 ... Standard gas supply port 3 for quantitative analysis ... Six-way valve 4 ... Ten-way valve 5 ... First electromagnetic on-off valve 6 ... Second electromagnetic on-off valve 7 ... Pump 8 ... Flow meter 9 ... Third electromagnetic on-off valve 10 ... Gas discharge port 11 ... Measuring tube 12 ... Pre-column 13 ... Main column 14 ... Dummy column 15 ... Choke column 16 ... Detectors 17, 18 ... Carrier gas supply port 20 ... Control unit 21 ... Data processing unit 22 ... Operation unit 23 ... Display unit F1 ... Sample gas supply channel F2 ... Sample gas recovery channel

Claims (3)

A gas sample introduction device for introducing a sample gas into a gas analysis unit, a measuring tube having a predetermined internal volume, and a charging state in which the sample gas is flown through the measuring tube so as to hold the sample gas in the measuring tube A sampling valve that switches a flow path between a sampling state in which a carrier gas is flown through the measuring tube so that the sample gas held in the measuring tube is pushed out and introduced into the gas analyzer, and a sample is supplied to the sampling valve in a charging state In a gas sample introduction device comprising: a sample gas supply channel for supplying a gas; and a sample gas recovery channel for recovering the sample gas that has passed through the measuring tube in the charging state from the sampling valve;
a) first channel opening / closing means provided on the sample gas supply channel;
b) a second channel opening / closing means provided on the sample gas recovery channel;
c) third flow path opening / closing means having one end connected to the sample gas recovery flow path between the second flow path opening / closing means and the sampling valve and the other end reaching the discharge port;
d) When the sampling valve is switched from the sampling state to the charging state, the first and second flow path opening / closing means are closed and the third flow path opening / closing means are opened prior to charging the sampling valve. Control for controlling the operation of each channel opening / closing means and the sampling valve so that the first and second channel opening / closing means are opened and the third channel opening / closing means are closed after a predetermined time has elapsed after switching to the state. Means,
A gas sample introduction device comprising:   The ends of the sample gas supply channel and the sample gas recovery channel are connected to a measurement container having a predetermined internal volume, and the sample gas sealed in the measurement container is collected in the measuring tube and supplied to the gas analysis unit. The gas sample introducing device according to claim 1, wherein the introducing operation is repeatedly performed. The gas sample introduction device according to claim 1, wherein the gas analysis unit is a gas chromatograph including a separation column and a detector that detects a sample component separated by the column.

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