JP4240665B2 - Calibration gas preparation device and gas analyzer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a calibration gas preparation device and a gas analysis device that calibrates an analysis unit using a calibration gas. More specifically, the present invention relates to span calibration by diluting a high-concentration standard gas filled in a high-pressure vessel. The present invention relates to a calibration gas preparation device and a gas analysis device that are used as span gas. In this specification, span calibration includes not only calibration of the scale value near the maximum scale in the predetermined measurement range of the analyzer, but also calibration of the scale value between the maximum scale and the minimum scale. The standard gas used for calibration is the span gas.
[0002]
[Prior art]
In a gas analyzer that analyzes trace components in gas, such as pollutants in the environmental atmosphere, the analyzer is periodically calibrated with zero gas and a span gas with a known concentration. Of these, the span gas is required to have a concentration within or close to the concentration range that the analysis target component in the sample gas can normally take.
[0003]
However, since it is generally difficult to store a low-concentration standard gas from the viewpoint of stability, usually, a high-concentration standard gas filled in a high-pressure vessel is diluted with zero gas and used. For example, in a sulfur oxide or nitrogen oxide analyzer having an environmental standard of 40 ppb, a standard gas of about 45 ppm or 90 ppm is diluted to 90 ppb and used as a span gas.
[0004]
FIG. 1 shows a basic configuration of a gas analyzer 1 for obtaining span gas in this way. In FIG. 1, 10 is a zero gas supply line, 20 is a standard gas supply line, 30 is a calibration gas supply line, and these three lines basically constitute a calibration gas preparation apparatus. Reference numeral 40 denotes a sample gas introduction line, 50 denotes a switching member such as a three-way valve, and 60 denotes an analysis unit.
[0005]
The zero gas supply line 10 includes a pump 11, a purifier 12, and a flow rate controller 13, and a gas that becomes a material of zero gas introduced by the pump 11 from the material gas inlet 14 is purified by the purifier 12, and has a predetermined flow rate. Zero gas can be supplied. As the zero gas material gas, it is easy to use the same gas as the sample gas, for example, the atmosphere if it is an atmospheric analyzer.
[0006]
The standard gas supply line 20 includes a high-pressure vessel 21, a pressure regulator 22, an on-off valve 23, and a flow rate controller 24 so that the standard gas in the high-pressure vessel 21 can be supplied at a predetermined flow rate when the on-off valve 23 is opened. It has become.
[0007]
The calibration gas supply line 30 is a combination of the zero gas supply line 10 and the standard gas supply line 20, and a span gas in which the zero gas and the standard gas are mixed depending on the open / close state of the on-off valve 23 when the pump 11 is operated. Alternatively, only zero gas can be supplied as calibration gas. Reference numeral 31 denotes an overflow pipe provided in the calibration gas supply line 30 so that the remaining calibration gas supplied to the analysis unit 60 via the switching member 50 is discharged.
[0008]
The sample gas introduction line 40 can introduce the sample gas from the sample gas inlet 41 via a filter, a sampling pump or the like (not shown). The switching member 50 selects any one of the calibration gas supply line 30 and the sample gas introduction line 40 and distributes the gas to the analysis unit 60 side.
[0009]
In the gas analyzer shown in FIG. 1, when the analyzer is calibrated, the pump 11, the on-off valve 23, and the switching member 50 are operated as shown in FIG. That is, in calibration with zero gas, as shown in FIG. 6A, with the on-off valve 23 closed, at the start of calibration, the pump 11 is turned on and the switching member 50 is set to the calibration gas line side. At the end of calibration, the pump 11 is turned off and the switching member 50 is set to the sample gas line side at the same time.
[0010]
In the calibration with span gas, as shown in FIG. 6B, at the start of calibration, the pump 11 is turned on, the on-off valve 23 is opened, and the switching member 50 is set to the calibration gas line side. At the end of calibration, the pump 11 was turned off, the on-off valve 23 was closed, and the switching member 50 was moved to the sample gas line side at the same time.
[0011]
[Problems to be solved by the invention]
When the gas analyzer shown in FIG. 1 is operated as shown in FIG. 6, there are the following problems.
[0012]
(1) When starting span calibration, a high-concentration standard gas may be supplied to the analysis unit 60 prior to a span gas having an appropriate concentration. As a result, not only does it take time for the calibration gas concentration to stabilize, but also the high-concentration standard gas is adsorbed in the calibration gas supply line 30 or the analysis unit 60, which may cause errors in subsequent calibration and measurement. there were. As a result of investigations by the present inventors, the cause is that the supply pressure of zero gas immediately increases even when the pump is operated due to the deterioration of the pump capacity and the resistance when passing through the purifier having a certain capacity. I found that there was nothing.
[0013]
{Circle around (2)} Calibration is preferably completed after the last zero calibration. However, in the case of manual calibration, calibration sometimes ends with span calibration being performed. In this case, the span gas may remain in the calibration gas supply line 30 or the analysis unit 60, which may cause an error in subsequent measurement or the next zero calibration.
[0014]
(3) Since the sample gas cannot be measured during calibration, there is a demand to finish the calibration work in as short a time as possible. The calibration cannot be performed unless the indicated value of the analysis unit 60 when the calibration gas is introduced is stable, but the time until the indicated value is stabilized is not necessarily short enough.
[0015]
(4) During the measurement of the sample gas, the gas in the piping of the calibration gas preparation device does not flow. For example, the gas in the piping of the calibration gas preparation device gradually increases due to a small amount of impurities released from the piping material. There was a concern of contamination.
[0016]
(5) When the standard gas leaks very little even though the on-off valve 23 is closed (so-called slow leak), it is extremely difficult to detect. Even in such a slight leak, there is a possibility that the standard gas having a concentration that affects the next calibration is filled during the measurement of the sample gas in which the gas in the piping of the calibration gas preparation apparatus is not flowing.
[0017]
(6) During the measurement of the sample gas in which the gas in the piping of the calibration gas preparation device is not flowing, the high-concentration standard gas remaining in the standard gas supply line enters the zero gas supply line due to diffusion, and the purifier 12 There was a risk of contamination.
[0018]
The present invention has been made in view of the above circumstances, and prevents the calibration gas preparation device and the analysis unit from being contaminated, and also does not affect the measurement accuracy of the gas analyzer even if it is contaminated. It is an object of the present invention to provide a gas preparation device for gas and a gas analyzer.
[0019]
In order to solve the above-described problems, the present invention provides a zero gas supply line that supplies a gas that has passed through a purifier by a pump as a zero gas, a standard gas supply line that supplies a standard gas of a high-pressure vessel via an on-off valve, and a zero gas A calibration gas supply line formed by joining a supply line and a standard gas supply line, and supplying the zero gas from the calibration gas supply line by operating the pump with the on- off valve closed; or, an the calibration gas preparation device or we subjected to feed the calibration gas supply line span gas prepared by diluting the standard gas in the zero gas by the pump in a state of opening the opening and closing valve is actuated A calibration gas preparation device having the following characteristics is provided.
[0020]
First, the calibration gas preparation device of claim 1, when starting the supply of the span gas, the on-off valve is characterized in that opening after the pump has operated for a predetermined time. Thus, since the standard gas is merged after the supply pressure of the zero gas is sufficiently increased, the problem that the high concentration standard gas is supplied to the analysis unit prior to the span gas having an appropriate concentration can be avoided. it can. Even if the zero gas supply line or the calibration gas supply line is filled with impurities, standard gas components, or the like, the gas can be flushed out of the apparatus prior to the span gas supply.
[0021]
Further, calibration gas preparation device according to claim 2, at the time of terminating the supply of the span gas, the pump is characterized in that subsequently continued operation a predetermined time even after the on-off valve is closed. As a result, even if the calibration is terminated while performing the manual span calibration, the span gas remains in the calibration gas supply line 30 and gives an error to the next zero calibration. Can be resolved.
[0022]
In order to solve the above problems, the present invention provides a zero gas supply line that supplies, as a zero gas, a gas that has passed through a purifier by a pump, and a standard gas supply line that supplies a standard gas of a high-pressure vessel via an on-off valve A calibration gas supply line formed by joining the zero gas supply line and the standard gas supply line, and the zero gas is removed from the calibration gas supply line by operating the pump with the open / close valve closed. A calibration gas preparation unit that supplies or supplies a span gas prepared by diluting the standard gas with the zero gas by operating the pump with the open / close valve open; and from the calibration gas supply line; an analysis unit for analyzing the supplied gas, the sample gas introduction line that sample gas is introduced, the sample gas introduction line and the calibration gas supply line And a switching member for circulating either a gas line to the analysis unit side by selecting of the span gas is supplied to the analyzer by selecting the calibration gas supply line side by the switching member A gas analyzer that performs span calibration and has the following characteristics is provided.
[0023]
First, the gas analyzer according to claim 3, when starting the supply of the span gas, the on-off valve is characterized in that opening after the pump has operated for a predetermined time. Thus, since the standard gas is merged after the supply pressure of the zero gas is sufficiently increased, the problem that the high concentration standard gas is supplied to the analysis unit prior to the span gas having an appropriate concentration can be avoided. it can. Even if the zero gas supply line or the calibration gas supply line is filled with impurities, standard gas components, or the like, it can be flushed out of the apparatus prior to span calibration and cleaned.
[0024]
The gas analyzer according to claim 4, when to terminate the supply of the span gas, the pump is characterized in that subsequently continued operation a predetermined time even after the on-off valve is closed. As a result, even if the calibration is terminated while performing the manual span calibration, the span gas remains in the calibration gas supply line 30 and gives an error to the next zero calibration. Can be resolved.
[0025]
In order to solve the above-mentioned problems, the present invention provides a zero gas supply line for supplying, as zero gas, a gas passed through a purifier by a pump, and a standard gas in a high-pressure vessel through an on-off valve. And a calibration gas supply line formed by joining the zero gas supply line and the standard gas supply line, and the zero gas is generated by operating the pump with the open / close valve closed. Is supplied from the calibration gas supply line, or the span gas prepared by diluting the standard gas with the zero gas by operating the pump with the open / close valve opened is supplied from the calibration gas supply line. a calibration gas preparation unit that, the analysis unit for analyzing the supplied gas, the sample gas introduction line that sample gas is introduced, the calibration gas supply line A switching member for flowing gas to the analyzer side by selecting one line of the sample gas introduction line, and a overflow pipe located upstream of the downstream and the switching member of said calibration gas preparation unit comprising, before SL gas analyzer by the switching member to supply the span gas or the zero gas by selecting the calibration gas supply line side to said analyzing unit for span calibration or zero calibration, the span calibration or zero calibration When starting the operation, the switching member selects the calibration gas supply line after the pump has been operated for a predetermined time.
[0026]
As a result, even if the zero gas supply line or the calibration gas supply line is full of impurities, standard gas components, etc., before the calibration gas is supplied to the analyzer, it is flushed out of the equipment and cleaned. I can leave. For this reason, since the calibration gas can be introduced into the analysis section after its properties are stabilized, the time until the indicated value of the analysis section is stabilized can be shortened after the calibration gas supply line side is selected by the switching member. As a result, the time during which the sample gas cannot be measured by the calibration operation can be shortened as much as possible.
[0027]
Further, in order to solve the above-mentioned problems, the present invention provides a zero gas supply line for supplying a gas passed through a purifier by a pump as a zero gas and a standard gas in a high-pressure vessel through an on-off valve. And a calibration gas supply line formed by joining the zero gas supply line and the standard gas supply line, and the zero gas is generated by operating the pump with the open / close valve closed. Is supplied from the calibration gas supply line, or the span gas prepared by diluting the standard gas with the zero gas by operating the pump with the open / close valve opened is supplied from the calibration gas supply line. a calibration gas preparation unit that, the analysis unit for analyzing the supplied gas, the sample gas introduction line that sample gas is introduced, the calibration gas supply line And a switching member for flowing gas to the analyzer side by selecting one line of the sample gas introduction line, and an overflow pipe located upstream of the downstream and the switching member of said calibration gas preparation unit in the gas analyzer including a state wherein the analysis unit by said switching member to select the sample gas introduction line side during a period in which analyzed for the sample gas, the pump, said opening and closing valve is closed in to provide a gas analyzer apparatus characterized that you operate regularly Jo Tokoro time.
[0028]
Thereby, the gas in the piping of the calibration gas preparation device and the purifier can be periodically flowed and discharged even during the measurement of the sample gas. Therefore, even if the zero gas supply line is contaminated due to trace impurities released from the piping material, slow leak of standard gas, diffusion of high concentration standard gas remaining in the standard gas supply line, etc., calibration at the next calibration It can be cleaned regularly so as not to affect the concentration and purity of the working gas.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each of the following figures is a time chart for explaining the operating state of the gas analyzer 1 shown in FIG.
FIG. 2 is a time chart showing an operation content of the gas analyzer 1 when one embodiment of the present invention is instructed to manually perform zero calibration. As shown in FIG. 2, the timing of switching from the sample gas introduction line 40 to the calibration gas supply line 30 by the switching member 50 is slightly delayed, for example, about 10 seconds from the timing of operating the pump 11. The time for setting the switching member 50 on the calibration gas supply line 30 side and supplying the zero gas to the analysis unit 60 is usually about 20 minutes.
[0030]
According to this embodiment, even if the zero gas supply line 10 or the calibration gas supply line 30 is filled with impurities, components of standard gas, or the like, while the pump 11 is being operated, the overflow pipe 31 is removed from the apparatus. It can be washed out and kept clean. For this reason, the purity of the zero gas is increased by the time when switching is performed by the switching member 50 so that the calibration gas supply line is circulated to the analysis unit 60 side. As a result, the time during which the sample gas cannot be measured by the zero calibration operation can be shortened as much as possible.
[0031]
FIG. 3 is another embodiment of the present invention, and is a time chart showing the operation content of the gas analyzer 1 when manual span calibration is instructed. As shown in FIG. 3, the timing for opening the on-off valve 23 is slightly delayed, for example, about 10 seconds from the timing for operating the pump 11. In addition, the timing of switching from the sample gas introduction line 40 to the calibration gas supply line 30 by the switching member 50 is further slightly sent, for example, about 10 seconds. Thereafter, for example, after about 20 minutes, the on-off valve 23 is closed and the switching member 50 switches from the calibration gas supply line 30 to the sample gas introduction line 40. However, the pump 11 does not stop at the same time, It is designed to operate continuously for about 5 minutes.
[0032]
According to this embodiment, since the standard gas is merged after the supply pressure of the zero gas is sufficiently increased, the high concentration standard gas is preceded by the span gas having an appropriate concentration, and the calibration gas supply line 30 and the analysis unit 60 are used. The problem of being supplied to can be avoided.
[0033]
Further, even if the zero gas supply line 10 or the like is contaminated, it can be flowed out of the apparatus prior to span calibration and kept clean. Furthermore, since the span gas can be introduced into the analysis section after its concentration is stabilized, the time until the indicated value of the analysis section 60 is stabilized after the calibration gas supply line 30 side is selected by the switching member can be shortened. The time during which the sample gas cannot be measured by the span calibration operation can be shortened as much as possible.
[0034]
In addition, even if the calibration is ended while performing the span calibration by mistake, the span gas remains in the calibration gas supply line 30 or the analysis unit 60, and an error is caused in the subsequent measurement or the next zero calibration. The problem of giving can be solved.
[0035]
FIG. 4 is still another embodiment of the present invention, and is a time chart showing the operation content of the gas analyzer 1 when the calibration signal from the analysis unit 60 is received and zero span calibration is automatically performed at a constant period. . As shown in FIG. 4, the timing of switching from the sample gas introduction line 40 to the calibration gas supply line 30 by the switching member 50 is slightly delayed, for example, about 10 seconds from the timing of operating the pump 11. Thereafter, the on-off valve 23 is opened from closed for about 20 minutes, and then closed. During this time, the analyzer 60 can perform zero calibration, span calibration, and final zero confirmation. The timing at which the pump 11 is stopped and the timing at which the switching member 50 switches from the calibration gas supply line 30 side to the sample gas introduction line 40 side are the same.
[0036]
According to this embodiment, even if the zero gas supply line 10 or the like is contaminated, it can be cleaned in advance. For this reason, the purity of the zero gas is increased by the time when switching is performed by the switching member 50 so that the calibration gas supply line is circulated to the analysis unit 60 side. As a result, the time during which the sample gas cannot be measured by the zero calibration operation can be shortened as much as possible. Finally, since the pump 11 is operated even after the on-off valve 23 is closed, the span gas remains in the calibration gas supply line 30 and the analysis unit 60, and an error occurs in the subsequent measurement and the next zero calibration. Can solve the problem of giving.
[0037]
FIG. 5 shows still another embodiment of the present invention. The gas analyzer 1 that automatically performs zero-span calibration periodically in response to a calibration signal from the analysis unit 60 performs the following after the calibration operation is completed. It is a time chart which shows the operation | movement content at the time of carrying out an automatic washing | cleaning regularly within the period until the calibration operation | work of this starts. The calibration work is usually performed once a week or two weeks, but only the pump 11 is operated for about 3 minutes once a day as shown in FIG. 5 between the calibration work and the calibration work. Yes.
[0038]
According to the present embodiment, the gas in the piping of the calibration gas preparation device and the purifier is periodically flowed and discharged even during sample gas measurement in which the sample gas introduction line 40 is selected by the switching member 50. can do. For this reason, the zero gas supply line 10 and the purifier 12 provided in the zero gas supply line 10 due to a small amount of impurities released from the piping material, a slow leak of the standard gas, a diffusion of the high concentration standard gas remaining in the standard gas supply line 20, etc. Even if it is contaminated, it can be periodically cleaned so as not to affect the concentration and purity of the calibration gas at the next calibration.
[0039]
【The invention's effect】
According to the present invention, even if the zero gas supply line or the calibration gas supply line is filled with impurities, components of standard gas, or the like, it can be flowed out of the apparatus prior to the supply of the span gas or zero gas and cleaned. For this reason, since the calibration gas can be introduced into the analysis section after its properties are stabilized, the time during which the sample gas cannot be measured by the calibration operation can be shortened as much as possible.
[0040]
Further, in the span calibration, it is possible to avoid the problem that the high concentration standard gas is supplied to the analysis unit prior to the span gas having an appropriate concentration.
In addition, even if the calibration is terminated while performing the manual span calibration by mistake, the span gas remains in the calibration gas supply line 30 or the analysis unit 60 and the subsequent measurement or the next zero is performed. The problem of giving an error to calibration can be solved.
[0041]
Further, the gas in the piping of the calibration gas preparation device and the purifier can be periodically flowed and discharged during the sample gas measurement. Therefore, even if the zero gas supply line or the purifier is contaminated due to trace impurities released from the piping material, slow leak of standard gas, or diffusion of high concentration standard gas remaining in the standard gas supply line, the next calibration It can be cleaned regularly so as not to affect the concentration and purity of the calibration gas.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a gas analyzer according to the present invention.
FIG. 2 is a time chart showing an operation content according to the embodiment of the present invention.
FIG. 3 is a time chart showing operation contents according to another embodiment of the present invention.
FIG. 4 is a time chart showing the operation content according to another embodiment of the present invention.
FIG. 5 is a time chart showing operation contents according to another embodiment of the present invention.
FIG. 6 is a time chart showing the operation content according to the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Zero gas supply line 11 Pump 12 Purifier 20 Standard gas supply line 21 High pressure vessel 23 On-off valve 30 Gas supply line for calibration 40 Sample gas introduction line 50 Switching member 60 Analysis part

Claims (6)

The zero gas supply line that supplies the gas that has passed through the purifier by the pump as zero gas, the standard gas supply line that supplies the standard gas of the high-pressure vessel via the on-off valve, the zero gas supply line, and the standard gas supply line merge. A gas supply line for calibration, wherein the zero gas is supplied from the gas supply line for calibration by operating the pump with the open / close valve closed, or the open valve is opened with the open / close valve open. in the calibration gas preparation device or we subjected to feed the calibration gas supply line span gas prepared by diluting the standard gas in the zero gas by the pump is operated, when starting the supply of the span gas, the opening and closing A calibration gas preparation apparatus , wherein the valve is opened after the pump has been operated for a predetermined time. The zero gas supply line that supplies the gas that has passed through the purifier by the pump as zero gas, the standard gas supply line that supplies the standard gas of the high-pressure vessel via the on-off valve, the zero gas supply line, and the standard gas supply line merge. A gas supply line for calibration, wherein the zero gas is supplied from the gas supply line for calibration by operating the pump with the open / close valve closed, or the open valve is opened with the open / close valve open. in the calibration gas preparation device or we subjected to feed the calibration gas supply line span gas prepared by diluting the standard gas in the zero gas by the pump is operated, when to terminate the supply of the span gas, the pump Is a calibration gas preparation device that continues to operate for a predetermined time after the on- off valve is closed . The zero gas supply line that supplies the gas that has passed through the purifier by the pump as zero gas, the standard gas supply line that supplies the standard gas of the high-pressure vessel via the on-off valve, the zero gas supply line, and the standard gas supply line merge. A calibration gas supply line, and the zero gas is supplied from the calibration gas supply line by operating the pump with the open / close valve closed, or the open / close valve is opened. A calibration gas preparation unit for supplying a span gas prepared by diluting the standard gas with the zero gas by operating the pump from the calibration gas supply line, an analysis unit for analyzing the supplied gas, and a sample gas the amount but by selecting a sample gas inlet line to be introduced, either of lines of the the calibration gas supply line the sample gas inlet line And a switching member for flowing gas into the part side, the gas analyzer for span calibration by supplying the span gas to the analyzer by selecting the calibration gas supply line side by the switching member, the span The gas analyzer according to claim 1, wherein when the gas supply is started, the on- off valve opens after the pump has been operated for a predetermined time. The zero gas supply line that supplies the gas that has passed through the purifier by the pump as zero gas, the standard gas supply line that supplies the standard gas of the high-pressure vessel via the on-off valve, the zero gas supply line, and the standard gas supply line merge. A calibration gas supply line, and the zero gas is supplied from the calibration gas supply line by operating the pump with the open / close valve closed, or the open / close valve is opened. A calibration gas preparation unit for supplying a span gas prepared by diluting the standard gas with the zero gas by operating the pump from the calibration gas supply line, an analysis unit for analyzing the supplied gas, and a sample gas the amount but by selecting a sample gas inlet line to be introduced, either of lines of the the calibration gas supply line the sample gas inlet line And a switching member for flowing gas into the part side, the gas analyzer for span calibration by supplying the span gas to the analyzer by selecting the calibration gas supply line side by the switching member, the span When the gas supply is terminated, the pump continues to operate for a predetermined time after the on- off valve is closed . The zero gas supply line that supplies the gas that has passed through the purifier by the pump as zero gas, the standard gas supply line that supplies the standard gas of the high-pressure vessel via the on-off valve, the zero gas supply line, and the standard gas supply line merge. A calibration gas supply line, and the zero gas is supplied from the calibration gas supply line by operating the pump with the open / close valve closed, or the open / close valve is opened. a calibration gas preparation unit supplying a span gas prepared by diluting from the calibration gas supply line in the zero gas of the standard gas by Rukoto the pump is to operate, an analysis unit for analyzing the supplied gas, the sample a sample gas inlet line which the gas is introduced, the content by selecting one line of the a calibration gas supply line the sample gas inlet line A switching member for flowing gas into the section side, and a overflow pipe located upstream of the downstream and the switching member of said calibration gas preparation section, by pre-Symbol switching member for selecting the calibration gas supply line side a gas analyzer for span calibration or zero calibration by supplying the span gas or the zero gas to the analyzer by, when starting the span calibration or zero calibration, the switching member is actuated the pump for a predetermined time After that, the calibration gas supply line side is selected. The zero gas supply line that supplies the gas that has passed through the purifier by the pump as zero gas, the standard gas supply line that supplies the standard gas of the high-pressure vessel via the on-off valve, the zero gas supply line, and the standard gas supply line merge. A calibration gas supply line, and the zero gas is supplied from the calibration gas supply line by operating the pump with the open / close valve closed, or the open / close valve is opened. A calibration gas preparation unit for supplying a span gas prepared by diluting the standard gas with the zero gas by operating the pump from the calibration gas supply line, an analysis unit for analyzing the supplied gas, and a sample gas the amount but by selecting a sample gas inlet line to be introduced, either of lines of the the calibration gas supply line the sample gas inlet line A switching member for flowing gas into the part side, the gas analyzer and a downstream and an overflow tube arranged upstream of the switching member of said calibration gas preparation unit, wherein the switching member is the sample gas introduction line side during a period in which the analysis unit is performing an analysis of the sample gas by selecting the pump, gas analyzer, it characterized that you operate regularly Jo Tokoro time in a state where the on-off valve is closed .

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