JP2006329823A - Analyzer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an analyzer having one measuring means capable of detecting a plurality of component concentrations, capable of calibrating easily and accurately a measuring component wherein securement of a stable calibration gas is difficult, and having high measurement accuracy. <P>SOLUTION: In this analyzer, a sample including a measuring object component A is introduced into a conversion means X for converting the measuring object component A disposed separately in a sampling system comprising a sample collection means, a sample treating means and a calibration means into a measuring object component B, and the converted sample is detected by a measuring means 5, and comparison operation is performed between an output related to the measuring object component A from the measuring means 5 before and after introduction and an output related to the measuring object component B from the measuring means 5 before and after introduction. Hereby, check of a detection function and/or a calibration function and/or a treating and processing function of the sample treating means and/or an operation processing means, and/or processing based on each function are performed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an analyzer capable of detecting a plurality of component concentrations, and is particularly useful as a gas analyzer in which a span gas at the time of device calibration is difficult to obtain.

  In general, in measurement of components in various samples, such as a nitrogen oxide (hereinafter referred to as “NOx”) analyzer in the atmosphere or exhaust gas from a fixed emission source or a mobile emission source, a plurality of measurement target components ( (Hereinafter referred to as “measurement component”)), it is required to detect multiple components at the same time, and by periodically introducing zero gas and span gas to calibrate the instrument, Maintains reliability.

Taking a NOx analyzer as an example, in order to simultaneously measure nitrogen monoxide (hereinafter referred to as “NO”) and nitrogen dioxide (hereinafter referred to as “NO ₂ ”) constituting NOx, a chemiluminescence method or non-dispersion is mainly used. using a measuring device for detecting only nO, such as formula infrared absorption method, with measuring the total NOx concentration by converting the nO ₂ in the sample to nO by converting means, nO concentration obtained when no conversion, and NOx concentration A method of obtaining the NO ₂ concentration by subtracting the NO concentration from the above can be mentioned.

Specifically, FIG. 8 shows a configuration example of an atmospheric NOx automatic measuring instrument using the chemiluminescence method that is widely used (for example, Non-Patent Document 1).
The sample collected by suction from the sample atmosphere inlet 61 is sucked by a suction pump (sample atmosphere suction pump) 63 provided at a subsequent stage of the measuring means (reaction tank) 65 and cleaned by the dust filter 62, and then the flow rate control unit. 71, introduced into the measuring means 65 via an electromagnetic valve (switching valve) 67. A converter 64 is provided in one flow path between the electromagnetic valve 67 and the measuring means 65 (flow path Sa), and a flow path resistance 66 is provided in the other flow path in relation to a pressure balance with the converter 64 ( Flow path Sb).

During normal measurement, NO ₂ in the atmosphere is connected to the flow path Sa and converted to NO, and the total NOx is measured. When measuring only NO or NO _2, it is possible to obtain NO ₂ by switching to the flow path Sb, detecting only NO in the atmosphere, and subtracting NO from NOx immediately before or after switching. Thus, NO, NO ₂ and NOx can be measured by the configuration of switching the flow path.

Here, ozone (hereinafter referred to as “O ₃ ”) source gas is separately introduced into the measuring means 65 via the ozone generator 72. The gas that has passed through the measuring means 65 is discharged to an exhaust duct or the like after performing necessary processing, for example, decomposing residual ozone (the decomposer is not shown). The measuring means 65 can measure the NO concentration in the sample by detecting the light quantity (hν) generated by the following reaction by the photoelectric photometric unit (photometric unit) 73,
NO + O ₃ → NO ₂ * + O ₂
NO ₂ * → NO ₂ + hν
The output of the photometry unit 73 is clearly indicated by the instruction recorder 75 via the amplifier 74. One of the features of this measuring method is that it has an excellent characteristic that the relationship between concentration and output becomes a straight line over a wide concentration range.

  At this time, zero gas is introduced into the measuring means 65 for calibration of the zero point of the measuring instrument, zero adjustment is performed, and span gas of a predetermined concentration is introduced into the measuring means 65 for calibration of detection sensitivity, and a preset predetermined concentration is set. The span is adjusted so that the output value corresponds to. Although the calibration gas inlet is not disclosed, it is generally introduced from the part (a) or the part (b) in FIG. As shown in the JIS standard, zero gas contains 0% (gas not containing NO) of the maximum scale value (hereinafter referred to as “FS”) of the measurement range, and span gas contains NO at a concentration of 80 to 100% of the measurement range. It is common to use gas.

In addition, as a method for detecting NO and NO ₂ simultaneously and continuously in parallel, an analyzer using a chemiluminescence method in each of the subsequent stages of both the channels A and B in the above method (hereinafter referred to as “CLD”). A method using both a measuring means for detecting only NO and a measuring means for detecting only NO ₂ can be considered. Further, without using the converter 4, an analyzer using a non-dispersive infrared absorption method (hereinafter referred to as “NDIR”) having a NO detection unit and a NO ₂ detection unit, which will be described later, and a non-dispersion ultraviolet absorption. It is conceivable to use a method analyzer (hereinafter referred to as “NDUV”) to directly detect NO and NO ₂ in the data and add each concentration and both to obtain the NOx concentration.
Japanese Industrial Standard "JIS B7953-1997"

However, the analyzer described above may have the following problems.
In the measurement means capable of simultaneously detecting NO and NO ₂ in parallel, it is preferable that it is possible to confirm whether the measurement means of each component is correctly detected even during measurement. For example, the occurrence of a measurement error such as a measurement value higher or lower than the true value due to interference with other components coexisting in the sample is applicable.

  However, the presence or absence of such an effect cannot be confirmed in the state where the sample is actually measured. For this reason, data such as interference effects of coexisting components is obtained and the measured values are corrected. However, if the concentration of the actual measured components is low, the magnitude of the error effect on the measured values is ignored. However, there was a strong demand for confirmation of the degree of influence or confirmation that the measurement component was truly measured.

Further, in the measurement means capable of detecting NO and NO ₂ simultaneously in parallel, calibration of individual measurement components is preferable. For example, measurement having strong adsorptive properties such as NO ₂ Regarding components, it may be difficult to ensure long-term stability of the high-pressure gas used as the calibration gas. In addition, for example, the occurrence of measurement errors due to overshoot due to residual components in the pressure adjusting unit and piping until the introduction of the calibration gas from the high-pressure gas container or poor reproducibility of calibration due to response delay cannot be ignored. In particular, there is a problem in that the use of a low-concentration high-pressure gas has a great influence, and a calibration gas having a low concentration cannot be used.

Such a problem with the calibration gas corresponds to not only NO ₂ but also low-concentration ammonia (NH ₃ ). In addition, in the case of components with high reactivity and poor stability of the substance to be measured such as hydrogen chloride (HCl) and chlorine (Cl ₂ ), it is not possible to maintain the same concentration for a long time in a gasified state. There is a problem that the calibration gas cannot be used substantially.

  For example, a standard gas generator may be provided separately for such problems, but long-term stable generators are expensive and may require additional equipment, increasing the complexity of the equipment and increasing the burden on maintenance. There is a great possibility that another problem such as this will occur, and from the viewpoint of the overall performance of the apparatus, there will be a new problem.

Furthermore, in the method of converting NO ₂ in the sample to NO by the conversion means and measuring it as NOx in the regular measurement, when the concentration of NO _{2 in} the sample is high, the conversion efficiency of the conversion means is relatively short. Since it decreases in the meantime, it is necessary to frequently maintain and replace it, and this is a problem as an analyzer that requires long-term continuous automatic operation. In particular, when the change in the NO ₂ concentration in the sample is large, it is difficult to determine when the conversion efficiency of the conversion means is reduced, and there is a strong demand for an analyzer that can check the conversion efficiency as needed.

  In addition, in the method of providing measuring means for each of a plurality of flow paths, or the method of combining measuring means having different principles or methods, it becomes expensive because it combines a plurality of measuring means having independent functions. Arises. In addition, a function that complements the difference in characteristics of each measuring means such as detection sensitivity, response speed, and the influence of multiple components is required, resulting in poor operability and complicating the analyzer.

  Therefore, the present invention solves such problems and has one measuring means capable of detecting a plurality of component concentrations, ensures reliability with respect to the measured value during sample measurement, and has a high measurement accuracy. The purpose is to provide. It is another object of the present invention to provide means capable of easily and accurately calibrating measurement components for which it is difficult to ensure a stable calibration gas. It is another object of the present invention to provide a means for easily inspecting the conversion efficiency of the conversion means when the measurement component is converted by the conversion means. In particular, when a substance containing the same element is used as multiple measurement components, there are many cases where a stable component and a component that does not exist coexist, and it is a problem to provide an analyzer with high measurement accuracy even under such conditions. It becomes.

  As a result of intensive studies, the present inventors have found that the above-described object can be achieved by an analyzer shown below, and have completed the present invention.

  The present invention comprises a sampling system comprising a sample collection means, a sample processing means, and a calibration means, a measurement means, and an arithmetic processing means, and can detect at least the concentrations of the measurement target component A and the measurement target component B. A sample containing the measurement target component A is introduced into the conversion means X that selectively converts the measurement target component A separately provided in the sampling system into the measurement target component B, and the converted sample is converted into the measurement means. Detection of the measurement target component A of the measurement means by comparing the output related to the measurement target component A of the measurement means before and after introduction with the output related to the measurement target component B of the measurement means before and after introduction. Checking the function and / or the calibration function of the component A to be measured and / or the processing function of the sample processing means and / or the arithmetic processing means, and / or And performing a process based on ability.

That is, according to the present invention, the sample or calibration gas (hereinafter referred to as “sample or the like”) containing the measurement component A can be used under the condition that the measurement component A can be selectively converted into the measurement component B by the conversion means X or Y. )) By temporarily introducing part or all of the sample or the like into the conversion means X, checking the detection function and calibration function of the means for detecting the concentration of the measurement component A, and processing based on each function, That is, the correction of the error with respect to the concentration of the measurement component A including the interference effect of other components in the sample with respect to the output related to the measurement component A (hereinafter, “output related to the measurement component Z” is referred to as “output Z”) and the measurement component A Is to calibrate. At this time, the calibration of the measurement component A does not need to be calibrated by the measurement component A itself, but is characterized in that it is calibrated by the measurement component B obtained by converting the measurement component A. NH ₃ and NO ₂ Alternatively, when a component such as HCl or Cl _{2 that} is difficult to obtain a stable calibration gas is included in a part of the measurement target, a very effective technical effect can be obtained. Further, by confirming such functions, not only the function check of the measuring means but also the processing function check of the sample processing means and the arithmetic processing comparison calculation and the processing based on each function, that is, the conversion means Y described later. Sample conversion or flow path switching and detector output linked to switching are continuously performed. This makes it possible to easily check the detection function of the means for detecting the concentration of a specific measurement component, the calibration function, and the degree of influence of errors, and actually perform processing based on the function, especially during calibration. The calibration gas for the components can be made unnecessary or common.

  Further, the present invention is excellent in that the blank time of the measurement data accompanying the check or processing can be almost ignored because the check or processing of the plurality of functions can be performed simultaneously. Furthermore, the present invention converts the specific measurement component A into another measurement component B using the conversion means X or Y, and performs processing such as calculation based on the value detected as the measurement component B. In the case of measuring the component concentrations of both close concentrations, the measurement accuracy can be improved.

  The present invention is the above-described analyzer, wherein the measurement unit includes at least a detection unit that detects the concentration of the measurement target component A and a detection unit that detects the concentration of the measurement target component B, and is measuring the sample. The measurement unit component A is calibrated by introducing it into the conversion unit X and performing the comparison operation.

  As described above, the present invention does not need to be calibrated by the measurement component A itself, and is characterized in that it can be calibrated by the measurement component B obtained by converting the measurement component A. An unprecedented effect can be obtained by utilizing the measurement component A present in the sample. In other words, even when an actual sample is being measured, by introducing a part or all of the sample temporarily into the conversion means, it is possible not only to eliminate the need for calibration gas, but also to detect specific measurement components. There is an unprecedented advantage in that sensitivity calibration can be performed. Further, by using a measuring means having a detector for measuring each measurement component individually (hereinafter, “detector for detecting the concentration of measurement component Z” is referred to as “detector Z”), the detector output for the same sample can be obtained. Since the comparison operation can be performed at the same time, it is possible to take advantage of the advantage that the output operation error due to the time lag in output responsiveness can be minimized.

  The present invention is the above-described analyzer, and includes the influence of interference by other components in the sample on the output related to the measurement target component A by introducing the sample into the conversion means X during the measurement and performing the comparison calculation. An error with respect to the concentration of the measurement target component A is corrected.

  As described above, it is practically impossible to confirm the function of the measuring means and the error of the measured value during the actual sample measurement, and it is much less feasible to correct it. In the present invention, such a difficulty is obtained under the condition that the measurement component A can be selectively converted into the measurement component B, and other coexisting components are contained in the actual sample together with the measurement component A and the measurement component B. By comparing and calculating the output A and the output B before and after conversion in the existing state, an error is inspected and corrected for the concentration of the measurement target component A including the interference effect of other components.

  Further, in the present invention, the sample processing means has conversion means Y for selectively converting the measurement target component A into the measurement target component B, and the sample that has passed through the conversion means Y and the sample that has not passed through are converted periodically. The analyzer for detecting the concentrations of the measurement target component A and the measurement target component B by the measurement means having at least a detection unit for detecting the concentration of the measurement target component B, By introducing the sample into the conversion means X during the measurement and performing the comparison operation, the conversion efficiency of the conversion means Y is inspected and replaced with the conversion means X when the efficiency is reduced.

  That is, in the analysis apparatus according to the present invention, the measurement means capable of detecting the measurement component A and the measurement component B has at least the detector B, and the sample processing means selectively selects the measurement target component A as the measurement target component. In the case of having the conversion means Y for converting to B, the detector B functions to detect the measurement component A, and the combination of the detector B and the conversion means Y used during normal measurement functions to detect the measurement component A. To do. Therefore, by introducing a sample or the like into the separately provided conversion means X and performing a comparison operation, the conversion efficiency of the conversion means Y can be inspected and the processing function of the sample processing means can be checked.

  Further, in this configuration, since the detection is performed by the same detector B, the calibration of the output A makes it possible to match the sensitivity of the measurement unit corresponding to the measurement component A and the measurement unit corresponding to the measurement component B. The output B can be secured and calibration is unnecessary. Therefore, the detection efficiency of the measurement component A can be substantially confirmed and calibrated by inspecting the conversion efficiency using almost unused conversion means X. Further, when the conversion efficiency of the conversion means Y is lowered, it is possible to maintain the measurement accuracy by replacing it as it is and continuing the measurement. Further, by using the same detector B, it is possible to minimize an output calculation error due to a temporal shift in output responsiveness, and to detect a shift in detection sensitivity between a plurality of detectors and other external sources. The advantage that the error due to the factor can be eliminated can be utilized.

  The present invention is the above analysis apparatus, wherein the sample processing means has a reference gas supply flow path, a flow path having the conversion means Y, and a flow path not having the conversion means Y, and the three flow paths It is characterized by using a gas switching type measuring method or a fluid modulation type measuring method for performing switching.

  Instead of a method having separate detection units for the measurement component A and the measurement component B as the measurement unit, the measurement unit having one detection unit includes a reference gas, a sample processed by the conversion unit Y, and the conversion unit Y. The present invention can also be applied to the case of using a method of sequentially switching and introducing three gases of a sample that does not pass through. That is, by introducing a sample or the like into the separately provided conversion means X and performing a comparison operation, it is possible to check the conversion efficiency of the conversion means Y and check the processing function of the sample processing means, and substantially measure Confirmation and calibration of the component A detection function can be performed. Further, a function of replacing the conversion means Y when the conversion efficiency of the conversion means Y is reduced, a function of suppressing an output calculation error due to a temporal shift in output responsiveness, and detection sensitivity between a plurality of detectors Similar to the above, it is possible to secure a function of eliminating errors due to misalignment and other external factors. Here, the gas-switching measurement method, as will be described later, allows each component to be detected simultaneously by holding and calculating the output sequentially when each flow channel is sequentially switched at a constant cycle. As described later, the fluid modulation type measurement method obtains a plurality of modulated outputs in the switching period when each flow path is sequentially switched at a constant period. Refers to a measurement method capable of simultaneously detecting each component.

  As described above, by applying the present invention, it has one measuring means capable of detecting a plurality of component concentrations, and easily and accurately calibrate measurement components for which it is difficult to secure a stable calibration gas. Therefore, it is possible to provide an analyzer with high measurement accuracy. In particular, when a substance containing the same element is used as multiple measurement components, stable components and other components often coexist, and even under these conditions, it is possible to provide an analyzer with high measurement accuracy. It becomes. Further, the present invention can improve the measurement accuracy when measuring a plurality of component concentrations having relatively close concentrations.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Basic configuration of a plurality of component measuring analyzers according to the present invention>
The present invention is an analyzer for measuring a plurality of components in a sample, and calibrates the device using a gas obtained by introducing the sample into the conversion means X and converting a specific measurement component A into another measurement component B as a span gas. It is characterized by that. In particular, the present invention is suitable for securing a calibration means in an analyzer that targets measurement components for which span gas is difficult to obtain, such as NH ₃ , NO _2, HCl, and Cl ₂ . Hereinafter, as a specific embodiment, a case where the present invention is applied to a NOx analyzer using NDIR as a measuring means will be described as an example.

FIG. 1 illustrates a basic configuration of an analyzer according to the present invention (first configuration example).
The sample collected by suction from the sample inlet 1 is cleaned by the dust filter 2 and then divided into two through the suction pump 3, and one (flow channel Sa) selectively converts NO ₂ in the sample as the conversion means X. It is introduced into the measuring means 5 via the converter 4 that converts to NO, and the other (flow path Sb) is introduced into the measuring means 5 via the flow path resistance 6 without any treatment. During normal measurement, the flow path Sb is connected to the measuring means 5, and is connected to the flow path Sa during processing such as function check and calibration. Switching between the two is performed by an electromagnetic valve (switching valve) 7 provided upstream of the measuring means 5. Calibration gas is introduced from the calibration gas inlet 8. At this time, the measurement component A becomes NO ₂ and the converted measurement component B becomes NO. The output from the measuring means 5 is introduced into an arithmetic processing means (not shown), subjected to a comparison operation, and stored together with data such as the calibration coefficient of the measurement component NO ₂ , the conversion efficiency of the converter 4 and the error of the measurement component NO _2. Or further processed to display an image on a display unit (not shown) or the like and transfer / communicate to the outside of the apparatus.

  The converter 4 is preferably a unit in which, for example, a predetermined amount of carbon-based elements having graphite or activated carbon particles as a carrier and a molybdenum-based catalyst supported on the surface thereof are enclosed. This is because a high conversion efficiency T of 90 to 95% or higher can be secured at a low temperature of about 150 to 200 ° C. and the activity can be maintained for a long time.

  The measurement means 5 ensures the selectivity for the measurement component by (a) a method using a detector having selectivity for the measurement component, or (b) an optical filter (such as an interference filter) using a non-selectivity detector. And (c) a method of ensuring high selectivity by combining a detector having selectivity and an interference filter. Examples of the non-selective detector include a pyro detector and a thermopile detector in NDIR. Examples of the detector having selectivity include a pneumatic detector in which a measurement component in NDIR or a component having equivalent infrared absorption characteristics is enclosed.

Specifically, as an example of the method (a) or (c), a beam splitter 21 as shown in FIG. 2 is used, and NO and NO ₂ components are simultaneously obtained by the NO detector 22a and the NO ₂ detector 22b. The case where NDIR for multi-component measurement to detect is used is shown. As the beam splitter 21, for example, an interference filter for NO (a bandpass filter having a center wavelength of 5.4 μm) is used, and infrared light having a center wavelength of 5.4 μm transmitted through the beam splitter 21 is detected by the NO detector 22a. detecting, detection at 23 via the NO ₂ detector 22b (band-pass filter and 6.0μm center wavelength) of the interference filter for NO ₂ infrared wavelength region other than the transmissive infrared rays reflected by the beam splitter 21 To do. The infrared rays generated from the light source unit 24 are absorbed in the sample cell unit 25 in an amount corresponding to the concentrations of the measurement components NO and NO ₂ in the sample, and the infrared absorption amounts are detected by the detectors 22a and 22b. The concentration of NO and NO ₂ in the sample can be detected. The outputs from the detectors 22a and 22b are amplified by the preamplifiers 26a and 26b, respectively, and then amplified and calculated by the calculation processing unit 27.

In normal measurement, the sample is introduced into the measuring means 5 through the flow path Sb, and the NO component and NO NO are converted by converting the outputs of the NO detector 22a and NO ₂ detector 22b in the arithmetic processing unit 27. The concentration of the _two components and the concentration of the NOx components can be obtained simultaneously by adding them.

The measuring means 5 is not particularly limited as long as it has a method for detecting NO and a means for detecting NO ₂ , and NDUV can be used in addition to NDIR. As for NDIR, in addition to the method (a) or (c), there is NDIR having a plurality of solid state detectors (eg, pyro detectors) as exemplified in FIG. 3 as the method (b). Infrared light from the light source unit 24 is introduced into the detectors 31a, 31b, and 31c via the sample cell unit 25, and a chopper 32 driven by a motor is provided in the middle of the optical system, and the infrared light is intermittent light. Thus, the detectors 31a, 31b and 31c are introduced. Between the light source unit 24 and the detectors 31a, 31b, and 31c, optical filters 33a, 33b, and 33c that selectively transmit infrared light in a wavelength region corresponding to the normal measurement target component are provided and introduced into the sample cell unit 25. Only the change in infrared absorption due to the measured component in the sample gas is detected.

<Basic check or processing function of analyzer according to the present invention>
Next, a basic check or processing function of the analysis apparatus, which is one of the features of the present invention, will be described. The analyzer according to the present invention introduces a sample containing the measurement component A into the conversion means X separately provided in the sampling system, detects the converted sample by the measurement means 5, and outputs A and B before and after the introduction. (1) Calibration function of measurement component A, (2) Detection function of measurement component A (including a function for checking errors such as interference effects), (3) Processing function of sample processing means ( (Including the conversion function of the conversion means X), (4) the processing function of the arithmetic processing means, and / or processing based on any one or some combination of the functions. In particular, there is an advantage in that such a function can be checked or processed during sample measurement. Note that (4) the processing function of the arithmetic processing means can be checked or processed at the time of checking or processing the functions of (1) to (3). Also, (2) the detection function of the measurement component A is the same except for the error checking function such as interference influence, and (3) the processing function of the sample processing means is the same except for the conversion function of the conversion means X. is there.

(1) Checking or processing calibration function of measurement component A While measuring a sample or the like containing a plurality of measurement components A (concentration a), measurement component B (concentration b), measurement component C (concentration c) ( The output of the measurement means is individually output A = a, output B = b, output C = c,...), A sample or the like converted by introducing part or all of the sample into the conversion means X When the conversion efficiency of the conversion means X is 100% and there is no error such as interference effects of other components in the output A, the output of the measurement means is A ′ = 0 and B ′ = a ′ + b individually. , C ′ = c,. At this time, since the decrease amount of the output A and the increase amount of the output B are essentially the same and correspond to the concentration a of the measurement component A, it should be a = a ′. However, since there is actually a change in sensitivity of the measuring means, a ≠ a ′. Therefore, by obtaining the ratio of a and a ′ (calibration coefficient), the correlation between the sensitivity of the two can be known. That is, for example, if the sensitivity of the output A can be accurately calibrated, it means that the other sensitivity can be calibrated based on the sensitivity.

Specifically, in an analyzer having a measuring means having a NO detector and a NO ₂ detector, only the NO detector is calibrated during calibration of the device, and NO ₂ is converted to NO during sample measurement. introducing the sample to the conversion means X which can, after conversion to NO ₂ in the sample before conversion to NO detected by NO ₂ detecting section by measuring by NO detector, NO detector and NO ₂ detecting section It becomes possible to obtain the sensitivity ratio. As a result, NO ₂ can be calibrated based on calibrated NO, and unstable NO ₂ calibration gas can be dispensed with.

(2) Checking or processing of error checking function of measurement target component A Also, if there is an interference effect under the condition (1) above, if the sensitivity of output A is accurately calibrated (calibration The subsequent output A = a ″) and the error ΔA = a ″ −a ′. In other words, it is possible to detect the degree of influence of other components in the sample during measurement, and to obtain an actual measurement value with high accuracy by calculating and correcting the value with respect to the actual measurement value. .

  Specifically, it is possible to perform the calculation process at the same time as the measurement component A is calibrated. Further, when a calibration coefficient abnormality or the like occurs during calibration of the measurement component A, it is also possible to check the error based on the data at that time and perform correction processing.

(3) Checking or processing of conversion function of conversion means X In this analyzer, the conversion means X for converting the measurement component A into the measurement component B is used only when the measurement component A is calibrated or when an error is confirmed / corrected. Since it is used and not always used, the conversion efficiency is hardly lowered and it can be used for a long time. Therefore, since it is possible to maintain the conversion efficiency at the time of manufacture for a long time, it is also possible to take a method of storing the conversion efficiency at the time of manufacture and applying it to the calibration of the measurement component A or the error confirmation / correction. It is. However, since the calibration of the measurement component A plays an important role in this analyzer, the efficiency may be decreased in a relatively short period when the concentration of the measurement component A is high, so that it can be frequently inspected. preferable.

Specifically, a sample containing a plurality of measurement components A (concentration a), measurement component B (concentration b), measurement component C (concentration c)... Is introduced into the conversion means X having a conversion efficiency of T, when measuring the sample converted in a state where the measurement component A is calibrated and the error can be ignored, the output of the measurement means is individually A ′ = a × (1 −T), B ′ = a × T + b, C ′ = c,... (If the conversion efficiency T of the conversion means is ideally 100%, the output of the measurement means is individually A ′. = 0, B ′ = a + b, C = c,.
Therefore, the conversion efficiency T = 1−A ′ / a of the conversion means can be calculated.

(4) Simultaneous check or processing of each function As described above, it has been explained that each function can be checked or processed individually. However, in reality, there is a change or error in the sensitivity of the output A, and the conversion efficiency T It is necessary to check or process when it is unclear.

  At this time, first, a standard is set for two of these three indexes (for example, adoption of the immediately previous calibration coefficient, adoption of zero error or previous error value, adoption of 100% conversion efficiency), and output before and after conversion. A and B are compared and another one index is narrowed down. Next, a comparison operation is performed using the narrowed down index, and this is repeated in sequence, and calibration, correction, or conversion efficiency determination is performed to obtain highly accurate measured values based on data under one condition be able to. Alternatively, a highly accurate actual measurement value can be obtained by comparing and calculating the output A and the output B before and after conversion under a plurality of measurement conditions. Specifically, see the next section.

<Specific Checking Method and Processing Method for Analyzing Apparatus According to the Present Invention>
Further, using the basic check or processing function of the above-described analyzer, specifically, the instrument calibration of the NO / NO ₂ analyzer, the conversion efficiency check of the conversion means, and the error inspection and correction method will be described in detail. .

Usually, the analyzer calibrates with zero gas and span gas before the start of measurement or periodically, but for the NO ₂ component, since it is difficult to produce a stable span gas for a long period of time as described above, only zero calibration is performed. The span calibration in this analyzer is an instrument calibration using span gas only for the NO component.

In addition, the span calibration of the NO ₂ component and the inspection of the conversion efficiency T of the converter 4 in this analyzer can be performed by the following method. This will be described with reference to FIGS.

(1) Perform zero calibration for the NO component and NO ₂ component in advance, and perform span calibration only for the NO component.

(2) In a state where the flow path Sb is connected to the measuring means 5, the gas Z containing a predetermined amount of NO ₂ (regardless of the accuracy of concentration) is used as the sample gas from the sample inlet 1 or the calibration gas inlet 8. 5 is introduced.
The outputs of the NO detector 22a and the NO ₂ detector 22b at this time are stored in memory.
Here, it is assumed that the output of the NO component is 0 ppm and the output of the NO ₂ component is 100 ppm.

(3) Next, the gas Z is introduced into the measuring means 5 via the flow path Sa in a state where the electromagnetic valve 7 is operated and the flow path Sa including the converter 4 is connected to the measuring means 5.
The outputs of the NO detector 22a and the NO ₂ detector 22b at this time are stored in memory.

(3-1) Here, assuming that the output of the NO component is 90 ppm and the output of the NO ₂ component is 0 ppm, there is no error due to the interference effect of other components on the output of the NO ₂ component. Further, the conversion efficiency T of the converter 4 is 100% because the NO ₂ component is completely converted from the change in the output of the NO ₂ detector 22b.
At this time, since the output of the NO component is 90 ppm, it can be seen that the accurate value of the NO ₂ component before conversion is 90 ppm.
On the other hand, since the output of the NO ₂ component is 100ppm in (2), as the span calibration of NO ₂ component, multiplied by a multiplier (calibration factor) 90/100 = 0.9 to the output of the NO ₂ detector 22b A correct detection value can be obtained by performing the processing.
This also proves that the NO ₂ detector 22b is functioning properly.

(3-2) Next, it is assumed that the output of the NO component is 80 ppm and the output of the NO ₂ component is 10 ppm. If there is no error due to the influence of interference of other components on the output of the NO ₂ component, the conversion efficiency T = (100−10) / 100 = 90% of the converter 4 from the change in the output of the NO ₂ detector 22b. Become.
At this time, since the output of the NO component is 80 ppm, it can be seen that the accurate value of the NO ₂ component before conversion is 80/90 × 100 = 89 ppm.
On the other hand, since the output of the NO ₂ component in the pre-conversion is 100 ppm, as the span calibration of NO ₂ component, to the output of the NO ₂ detector 22b multiplying the multiplier (calibration factor) 89/100 = 0.89 processing By performing the above, a correct detection value can be obtained.
This at the same time proves that the NO ₂ detector 22b is functioning properly.

(4) Further, as conditions close to the sample to be actually measured, it is assumed that the output of the NO component in (2) is 50 ppm and the output of the NO ₂ component is 50 ppm.

  (4-1) Next, the gas Z is introduced into the measuring means 5 via the flow path Sa in a state where the electromagnetic valve 7 is operated and the flow path Sa including the converter 4 is connected to the measuring means 5.

(4-2) Here, when the output of the NO component is 90 ppm and the output of the NO ₂ component is 5 ppm, assuming that the output of the NO ₂ component has no error due to the interference effect of other components, it is for NO ₂ From the change in the output of the detector 22b, the conversion efficiency of the converter 4 becomes T = (50−5) / 50 = 90%.
At this time, since the output of the NO component is 90 ppm, it can be seen that the accurate value of the NO ₂ component before the conversion is (90-50) / 90 × 100 = 44 ppm.
On the other hand, since the output of the NO ₂ component before conversion is 50 ppm, the span calibration factor NO ₂ component, the ratio of the output of the NO ₂ component to exact values of NO ₂ component (calibration factor) 44/50 = 0 .88, and a correct detection value can be obtained by performing a process of multiplying the output of the NO ₂ detector 22b by a multiplier of 0.88.

(5) On the other hand, the case where it is unclear whether the output of the NO ₂ component has an error due to the interference effect of other components under the above conditions (3-2) and (4-2) will be considered.

(5-1) When the conversion efficiency Tx of the converter 4 is obtained in advance and coincides with the conversion efficiency T, NO ₂ is selectively converted to NO. This indicates that there is no error due to the interference effect of other components.

(5-2) When the above conversion efficiency T does not coincide with the conversion efficiency Tx of the converter 4 obtained in advance, Tx is applied as the conversion efficiency of the converter 4, and the output error Δ (NO _{2 of} NO ₂ component) ) Can be obtained.
That is, under the same conditions as the above (3-2), the true NO ₂ concentration is 80 / Tx (ppm). Next, from the ratio (calibration coefficient) f = 80 / Tx / (100-10) = 0.89 between this and the NO ₂ output difference (100−10) before and after conversion, the sensitivity to the NO ₂ output 100 before conversion Calibration is performed to obtain a post-conversion post-conversion NO ₂ output that includes an output error Δ (NO ₂ ). The difference between this and the true NO ₂ concentration is the output error Δ (NO ₂ ).
Δ (NO ₂ ) = 100 × 80 / Tx / (100−10) −80 / Tx
= 8.9 / Tx (ppm)
Further, under the same conditions as the above (4-2), the true NO ₂ concentration is (90-50) / Tx (ppm). Next, from the ratio (calibration coefficient) f = (90-50) / Tx / (50-5) = 0.89 between this and the NO ₂ output difference before and after conversion (50-5), NO ₂ before conversion Sensitivity calibration is performed on the output 50 to obtain a post-conversion NO ₂ output after conversion including an output error Δ (NO ₂ ). The difference between this and the true NO ₂ concentration is the output error Δ (NO ₂ ).
Δ (NO ₂ ) = 50 × (90−50) / Tx / (50−5) − (90−50) / Tx
= 4.4 / Tx (ppm)

(5-3) If none of the above applies, conversion by the converter 4 under two measurement conditions results in a calibration coefficient f, conversion efficiency T, and NO ₂ component output error Δ ( NO ₂ ) can be obtained.
Specifically, the condition (4) “NO component output 50 ppm, NO ₂ component output 50 ppm” is (4-2) condition “NO component output 90 ppm, NO ₂ component In addition to the case where the output is 5 ppm, for example, a sample having a condition of “NO component output of 70 ppm and NO ₂ component output of 30 ppm” is converted, and “NO component output is 90 ppm and NO ₂ component output is By setting the case of “4 ppm” and performing a comparison operation, an accurate measurement value can be calculated.
Specifically, if the calibration coefficient of the NO ₂ component output is f, the conversion efficiency of the converter 4 is T, and the output error of the NO ₂ component is Δ (assuming no difference under the above two conditions), Is established,
50 + 50 × f × T = 90 → f × T = 0.8
50 × f × (1−T) + Δ = 5 → Δ + 50f = 45
30 × f × (1−T) + Δ = 4 → Δ + 30f = 28
f = 0.925, Δ = 0.25 ppm, T = 86.5% can be obtained.
Therefore, in normal measurement, (NO ₂ component output × f−Δ) is applied as an output after correction of the NO ₂ component, thereby enabling highly accurate measurement.
If Δ can be calculated in accordance with the change of the coexisting component, a measured value with higher accuracy can be obtained.

  (6) Table 1 summarizes the above results.

(7) As described above, according to the present analyzing apparatus, the span calibration of the NO ₂ component can be performed without preparing a special span gas, and an unstable calibration gas of NO ₂ becomes unnecessary. At the same time, it is possible to inspect the conversion efficiency T of the converter 4 or the function and error of the measuring means. The calibration coefficient f, conversion efficiency T and NO ₂ component output error Δ (NO ₂ ) obtained in this way are stored until the next function check and processing or for a predetermined period of time, and compared with new data to maintain the analyzer. It can be effectively used as an index for determining whether or not it is necessary.
Furthermore, since the flow path Sa is not used during normal measurement, the converter 4 can be set so that the conversion efficiency T _{0 in the} initial state can be maintained, and the conversion efficiency T ₀ when the apparatus is manufactured. Can be stored in memory and used during calibration.
In particular, the sample gas used above is the actual sample itself, and the detection sensitivity of a specific measurement component can be calibrated by switching the sample to the conversion means at any time during measurement of the actual sample. The apparatus has an excellent function that it can be performed and the conversion efficiency T of the conversion means can also be inspected.

<Application of the above analyzer>
The analyzer having the above-described configuration and function can be applied not only to a NOx analyzer using a conversion unit that converts NO ₂ into NO, but also to the following analyzers.
(1) A NOx (/ NO / NO ₂ ) analyzer using NDIR or NDUV having a plurality of detectors including a NO detector and a NO ₂ detector, using a conversion means for converting NO into NO ₂ . It is useful for measuring the exhaust gas from the atmosphere or from fixed or mobile sources.
(2) Using NDIR or NDUV having a plurality of detectors including a NO detector and an NH ₃ detector (including NO ₂ detector) using a conversion means for converting NH ₃ into NO or NO ₂ There was NOx and NH ₃ analyzer. This is useful for monitoring and controlling the NH ₃ injection amount in a denitration plant.
(3) Using a conversion means for reacting NH ₃ and NO to convert to H ₂ O and N ₂ , including a NO detector and an NH ₃ detector (a NO ₂ detector can also be included), a plurality of detectors NOx and NH ₃ analyzer using NDIR or NDUV. As above, it is useful for monitoring and controlling the NH ₃ injection amount in a denitration plant.
(4) An HC / CO / CO ₂ analyzer using NDIR having a plurality of detectors including a CO detector and a CO ₂ detector, using a conversion means for converting hydrocarbon (HC) into CO or CO ₂ . It is useful for safety monitoring such as explosion prevention or gas monitoring of waste storage silos.

  Moreover, in the said analyzer, when the measurement component A and the measurement component B are the substances containing the same element, the characteristic of this invention can be utilized effectively. That is, a specific measurement component can be converted to another measurement component by a relatively simple conversion process such as oxidation or reduction by the conversion means. Therefore, from the correlation between the two measurement components as described above, the calibration of the analyzer can be facilitated, calibration gas can be eliminated or shared, or the efficiency of the conversion means can be easily confirmed.

<Another configuration example of the analyzer according to the present invention (second configuration example)>
Next, as an application of the first configuration example, it is possible to apply the technical idea of the present invention to a conventional analyzer and to provide the conversion means X for function check and processing.
Specifically, as illustrated in FIG. 4, the flow path Sa having the conversion means Y that selectively converts the measurement component A into the measurement component B in the sample processing means, and the concentration of at least the measurement component B in the measurement means 5 An analyzer for detecting the concentrations of the measurement component A and the measurement component B by switching between the sample that has passed through the conversion means Y and the sample that has not passed through the conversion means Y and introducing them into the measurement means 5 A method of checking and processing each function by arranging a flow channel Sc having conversion means X for selectively converting measurement component A into measurement component B in the sample processing means can be mentioned. Similarly, the case where the present invention is applied to a NOx analyzer using NDIR having only a NO detector as a measuring means will be described below. The measurement component A becomes NO ₂ and the converted measurement component B becomes NO.

A sample Sa (channel Sa) in which NO ₂ in the sample is converted into NO by a converter 4a that is a sampling means that is suctioned from the sample inlet 1 and cleaned by the dust filter 2, and the cleaning NO ₂ in the sample is converted to NO by the sample Sb (flow path Sb) that has passed through the flow path resistance 6 without being processed after being converted to the converter 4c, which is the conversion means X for function check and processing. The sample Sc (flow path Sc) is introduced into the measuring means 5 via the switching valve 7a. During normal measurement, the flow path Sa and the flow path Sb are switched. When the NO _{2 in} the sample is large or when the NO ₂ concentration measurement has an important role, it is performed constantly or frequently. During the function check and processing, the flow path Sa and the flow path Sc are switched by the switching valve 7a. Components such as gas switching, calibration gas introduction, and converters 4a and 4c are the same as those in the first configuration example.

The measuring means 5 can use a one-component NDIR having a NO detector, but can also use a multi-component NDIR having other detectors such as SO ₂ and CO. Here, a case of NDIR having only a NO detector will be described.

In normal measurement, the flow path Sa and the flow path Sb are switched by the switching valve 7a, and the concentrations of the NOx component and the NO component are obtained by switching the sample Sa and the sample Sb at a constant cycle and introducing them into the measuring means 5. it can, by subtracting the output from these measuring means 5 in the arithmetic processing unit 27, it is possible to obtain NOx component, the concentration of NO component and NO ₂ components simultaneously. At the time of function check and processing, the change of the concentration of the NO component is changed by switching the flow path Sa and the flow path Sc by the switching valve 7a and switching the sample Sa and the sample Sc at a constant cycle and introducing them into the measuring means 5. no Although it is possible to obtain the concentration of NOx component as a reference, obtained by subtracting the output from these measuring means 5 in the arithmetic processing unit 27, NOx component, serving as a reference concentration of nO component and nO ₂ component simultaneously be able to.

<Basic function of analyzer according to second configuration example>
Next, basic functions of the analyzer according to the second configuration example will be described.
The analysis apparatus according to the second configuration example introduces a sample containing the measurement component A into the conversion means X separately provided in the sampling system, detects the converted sample by the measurement means 5, and outputs the output A before and after the introduction. By comparing and calculating the output B before and after introduction, as in the first configuration example, (1) a calibration function for the measurement component A, and (2) a detection function for the measurement component A (a function for checking errors such as interference effects) are included. ), (3) processing function of the sample processing means (including the conversion function of the conversion means Y in this configuration example), (4) check of the processing function of the arithmetic processing means, and / or any one of the functions or Processing based on several combinations can be performed. The point that the function can be checked or processed during sample measurement, the point that a plurality of functions can be checked or processed at the same time during the check or processing, and the like are the same as in the first configuration example.

(1) Checking or processing of calibration function of measurement component A, and (2) Checking or processing of error check function of measurement target component A In this configuration example, the measurement means 5 normally has a concentration of measurement component A. Therefore, it is not necessary to check or process the calibration function of the measurement component A and the error check function independently, and to simultaneously perform the calibration of the measurement component B and the error check or processing. Is possible. However, since the actual measurement accuracy of the component A including the conversion means Y is inspected by checking or converting the conversion function of the conversion means Y, which will be described later, during the measurement of the actual sample, In addition, the component A calibration function and the error check function are checked or processed (hereinafter referred to as “confirmation of actual measurement accuracy”). Even in this configuration example, when the measuring means 5 has a detector for detecting the concentration of the measurement component A, it is possible to apply the same function as the check or processing of each function in the first configuration example. .

(3) Checking or processing of conversion function of conversion means Y The conversion efficiency of the conversion means Y is normally inspected at the time of manufacturing the analyzer, and at the time of regular inspection of the analyzer during actual operation (for example, once / year or 2 years) ) Re-inspect. However, in this configuration example, the conversion means Y is always used and comes into contact with the sample or the like, so there is a risk of a decrease in efficiency. When the concentration of the measurement component A is high, the efficiency may be decreased in a short period of time. The decrease in efficiency directly affects the measurement accuracy of the measurement component A. Therefore, it is important to check or process the conversion efficiency, and it is preferable that it can be frequently checked or processed. On the other hand, the conversion means X is used only when calibrating the measurement component A or when confirming / correcting the error, and is not always used. Therefore, the conversion efficiency is not lowered and can be used for a long time. Therefore, since the conversion efficiency at the time of manufacture can be maintained for a long time, the conversion efficiency at the time of manufacture is stored in memory, and the measurement component A is calibrated or the error is confirmed and corrected based on the value. Is possible. In addition, when the conversion efficiency of the conversion means Y is lowered, the measurement accuracy can be maintained by replacing it as it is and continuing the measurement. Thus, the two conversion means X and Y have the same function, but it is also possible to have a complementary function by changing their roles.

  Specifically, a sample including a plurality of measurement components A (concentration a), measurement component B (concentration b), measurement component C (concentration c),... Is measured by switching between the flow channel Sa and the flow channel Sb. In this case, when the conversion efficiency T of the conversion means Y is assumed, the outputs of the measurement means are individually A = a × TX = b, C = c,. Next, when measurement is performed by switching between the flow path Sc and the flow path Sb instead of the flow path Sa, and the conversion efficiency Tx of the conversion means X, the output of the measurement means is individually A ′ = a × Tx, B '= B, C' = c,...

  That is, since a = A ′ / Tx, the true concentration a of the measurement component A can be obtained using the known conversion efficiency Tx. Therefore, the conversion efficiency T = A / a = A × Tx / A ′ of the conversion means Y can be obtained.

<Specific Checking Method and Processing Method of Analyzing Device According to Second Configuration Example>
Further, using the basic check or processing function of the above-described analyzer, specifically, the instrument calibration of the NO / NO ₂ analyzer, the conversion efficiency check of the conversion means, and the error inspection and correction method will be described in detail. .

Since usually analyzer, the measurement before the start or periodically calibrate the zero gas and span gas for each component, checking and processing of the calibration and error for NO ₂ component as described above is not required, NO component Calibration is performed with zero gas and span gas only before starting measurement or periodically. However, in recent years, with the improvement of cogeneration power generation or automobile combustion conditions and exhaust gas treatment methods, the concentration of NO ₂ component in the sample has increased, and the NO ₂ component including the conversion efficiency T of the converter 4a has increased. The importance of managing the accuracy of actual measurements is increasing.

The inspection of the conversion efficiency T of the converter 4a or the measurement accuracy of the NO ₂ component in this analyzer can be performed by the following method. This will be described with reference to FIG.

  (1) Perform zero calibration and span calibration for the NO component in advance.

(2) A gas Z containing a predetermined amount of NO ₂ is introduced into the measuring means 5 from the sample inlet 1 or the calibration gas inlet 8 as a sample gas while periodically switching the flow path Sa and the flow path Sb.
At this time, the NO detector output in the measuring means 5 when the channel Sa and the channel Sb are connected is obtained. Assuming that 90 ppm and 0 ppm, respectively, the output when connected to the flow path Sa represents the concentration of (NO + NO ₂ ), and the output when connected to the flow path Sb represents the concentration of NO. The output is 0 ppm, and the output of the NO ₂ component is 90 ppm. Store each value in memory.

(3) Next, the operation of the switching valve 7a is changed, and the gas Z is introduced into the measuring means 5 while periodically switching the flow path Sc including the converter 4c and the flow path Sa. At this time, the output of the NO component and NO ₂ component calculated from the output when connected to each flow path is stored.
Here, the conversion efficiency Tx of the converter 4c is preferably stored in advance as a value at the time of manufacture or a value checked in advance (as described above, since it is not always used, its conversion efficiency Tx ), And a high conversion efficiency Tx of 90 to 100% is maintained. NO output components 0 ppm, the output of the NO ₂ component is assumed that a 95 ppm, when the conversion efficiency Tx = 95% of the converter 4c, the output of the NO component 0 ppm, the concentration a true NO ₂ component a = 95 / Tx = 100 (ppm).
Therefore, since the output of the NO ₂ component in (2) is 90 ppm, the conversion efficiency T = 90/100 = 90% of the converter 4a can be obtained.

(4) Further, as conditions close to the sample to be actually measured, it is assumed that the output of the NO component in (2) is 50 ppm and the output of the NO ₂ component is 40 ppm. That is, the NOx measurement value for the sample Sa is assumed to be 90 ppm, and the NO measurement value for the sample Sb is assumed to be 50 ppm.

(5) The operation of the switching valve 7a is changed to introduce the gas Z into the measuring means 5 while periodically switching the flow path Sc including the converter 4c and the flow path Sa.
Here, assuming that the NOx measurement value for the sample Sc is 95 ppm and the NO measurement value for the sample Sb is 50 ppm, that is, the output of the NO component is 50 ppm and the output of the NO ₂ component is 45 ppm, the conversion efficiency is assumed. Since Tx = 95%, the NO component output is 50 ppm, and the true NO ₂ component concentration a is a = 45 / 0.95 = 47 (ppm).
Therefore, since the output of the NO ₂ component in (4) is 40 ppm, the conversion efficiency T = 40/47 = 84% of the converter 4a can be obtained.

  (6) If the conversion efficiency T falls below a predetermined value (for example, 90%), the flow path c is used during normal measurement to ensure a conversion efficiency of 95% and maintenance of the converter 4a from the analyzer. The analyzer according to the present invention can be configured by outputting a replacement instruction and using the new flow path a for the new converter 4a as a function check and processing flow path.

(7) The information provided by the above operation is not limited to the checking and processing of the conversion efficiency of the converter 4a. The NO ₂ component detection function is checked and the error is confirmed through the output of the NO detector. checking substantially calibration function of NO ₂ component assumes calibration of NO component, that is, will be conducted to confirm the actual measurement accuracy, it is possible to ensure high accuracy measurements.

<Application of analyzer according to second configuration example>
The analyzer having the above-described configuration and function can be applied not only to a NOx analyzer using a conversion unit that converts NO ₂ into NO, but also to the following analyzers.
(1) A NOx analyzer using conversion means for converting NO ₂ to NO and using CLD or NDUV as a NO detector. It is useful for measuring the exhaust gas from the atmosphere or from fixed or mobile sources.
(2) A NOx analyzer using NDIR or NDUV having a NO ₂ detector using a conversion means for converting NO into NO ₂ . Similarly to the above, it is useful for measuring exhaust gas in the atmosphere or from a fixed emission source or a mobile emission source.
(3) A NOx and NH ₃ analyzer using NDIR or NDUV having a NO detector using a conversion means for converting NH ₃ into NO or NO ₂ . This is useful for monitoring and controlling the NH ₃ injection amount in a denitration plant.
(4) A NOx and NH ₃ analyzer using NDIR or NDUV having a NO detector using conversion means for reacting NH ₃ and NO to convert them into H ₂ O and N ₂ . As above, it is useful for monitoring and controlling the NH ₃ injection amount in a denitration plant.
(5) An HC / CO / CO ₂ analyzer using NDIR having a CO ₂ detector using a conversion means for converting hydrocarbon (HC) into CO or CO ₂ . It is useful for safety monitoring such as explosion prevention or gas monitoring of waste storage silos.
(6) A H ₂ / H ₂ O analyzer using NDIR or NDUV having a H ₂ O detector using a conversion means for converting H ₂ to H ₂ O. It is useful for safety monitoring such as explosion prevention or monitoring of supplied fuel.
(7) A CO / CO ₂ analyzer using NDIR having a CO ₂ detector using a conversion means for converting CO to CO ₂ . Useful for safety monitoring.
(8) Using a conversion means for converting a reducing sulfur compound such as hydrogen sulfide (H ₂ S) or methyl mercaptan (CH ₃ SH) into sulfur dioxide (SO ₂ ), NDIR or NDUV having an SO ₂ detector was used. Sulfur compound (total S) / SO ₂ analyzer. As above, it is useful for analyzing the behavior of sulfur compounds in the atmosphere or in chemical processes.

  In the analyzer, the characteristics of the present invention can be effectively utilized when the measurement component A and the measurement component B are substances containing the same element. That is, a specific measurement component can be converted to another measurement component by a relatively simple conversion process such as oxidation or reduction by the conversion means. Therefore, from the correlation between the two measurement components as described above, the calibration of the analyzer can be facilitated, calibration gas can be eliminated or shared, or the efficiency of the conversion means can be easily confirmed. Furthermore, it is possible to detect a plurality of measurement components with a single detector, which is useful in that the apparatus is compact and there is no difference in characteristics such as sensitivity deviation between different detectors.

<2 of another configuration example of the analyzer according to the present invention (third configuration example)>
Next, as an application of the second configuration example, it is based on a gas switching type measurement method or a fluid modulation type measurement method in which three gases of a reference gas, a sample processed by the conversion unit, and a sample not passing through the conversion unit are switched. An analyzer for measuring multiple components in a sample, which is a measuring means and includes a detection unit that detects at least the concentration of the measurement target component B as a part of the measuring means. Similarly to the above, a case where the present invention is applied to a NOx analyzer using NDIR will be described as an example. FIG. 5 illustrates the configuration of the analyzer according to the present invention.

In addition to the configuration of the second configuration example, (a) the reference gas R (flow path R) obtained by purifying the atmosphere or the clean gas by the purification means 9 is provided with the switching means 7a, and (b) the gas passing through the flow path Sa. It is characterized in that it can be measured again. By clarifying the reference at all times, it is possible to eliminate error factors of the measuring means 5, such as changes in the offset of the detector and zero-degree lift due to temperature effects. The functions of the flow path Sa, the flow path Sb, and the flow path Sc that are switched to be introduced into the measuring means 5, the gas switching, the introduction of the calibration gas, and the converters 4a and 4c are the same as those in the second configuration example. There, the measurement component a becomes NO _2, measurement component B to be converted becomes NO.

The measuring means 5 can use a one-component NDIR having a NO detector, but can also use a multi-component NDIR having other detectors such as SO ₂ and CO. Here, a case of NDIR having only a NO detector will be described.

In normal measurement, the flow path R, the flow path Sa, and the flow path Sb are switched by the switching valve 7a, and the reference gas R, the sample Sa, and the sample Sb are switched at a constant cycle and introduced into the measurement means 5, thereby NOx. The concentration of the component and the NO ₂ component or NO component can be obtained, and by subtracting the output from the measuring means 5 in the arithmetic processing unit 27, the concentrations of the NOx component, NO component and NO ₂ component can be obtained simultaneously. it can.

Further, in this apparatus, as indicated by the broken line in FIG. 4, a flow path Sc for converting NO ₂ in the sample into NO is provided by the converter 4c in the same manner as the (CHECK 1) flow path Sa (use during normal measurement). First, it is used when checking the conversion efficiency T of the converter 4 or checking the measurement accuracy of the NO ₂ component.The gas passing through the passage C is referred to as the sample Sc.) Or (CHECK2) The gas passing through the flow path Sa is again used. It is characterized by adding a configuration to be introduced from the sample inlet 1.

When performing an inspection of the conversion efficiency T of the converter 4a described later,
(CHECK1) The flow path Sc is used instead of the flow path Sa, the flow path R, the flow path Sc, and the flow path Sb are switched, and the reference gas R, the sample Sc, and the sample Sb are switched at a constant cycle and introduced into the measurement means 5. By doing so, it is possible to compare the conversion efficiency Tx of the reference converter 4c with the conversion efficiency T of the converter 4a used in actual measurement.
(CHECK2) The gas passing through the flow path Sa is introduced again from the sample inlet 1, and the flow path R, the flow path Sa, and the flow path Sb are switched by the switching valve 7a, and the reference gas R, the sample Sa, and the sample Sb are switched at a constant cycle. by introducing the measuring unit 5 in switched, it is possible to obtain the conversion efficiency T converter 4a from the comparison between the density of the original NOx component and NO ₂ component.

  The case of using the above-described (A) gas switching measurement method and (B) fluid modulation measurement method will be described below.

(A) Gas switching type measurement method As in the case of FIG. 3, the measurement means 5 has a chopper in the middle of the optical system in which the infrared light from the light source part is introduced into the detector via the sample cell part, and the infrared light is intermittent light. Thus, an NDIR (not shown) that detects only a change in infrared absorption due to a measurement component in the sample gas introduced into the sample cell portion is used. Regardless of whether or not gas is introduced into the sample cell or switched, an output corresponding to the amount of infrared absorption (NO concentration) inside the sample cell can be obtained.

The operation and output at this time are shown in FIGS.
(1) As shown in FIG. 6A, the flow path R, the flow path Sa, and the flow path Sb are switched by the switching valve 7a, and sample Sa-sample Sb-reference gas R is periodically switched at regular time intervals. And introduced into the measuring means 5.
(2) As shown in FIG. 6B, in each time interval, a stable detector output is held after a lapse of a predetermined time, and the concentration is converted.
(3) As shown in FIG. 6C, each output means NOx component concentration-NO component concentration-concentration zero in order. Therefore,
(The concentration of NO ₂ component) = (concentration of NOx component) - (concentration of NO component)
Therefore, the concentration of the NO ₂ component can be obtained by calculating the above equation.
Above, it is possible to obtain a concentration of the NOx component / NO component / NO ₂ component.

(B) Fluid Modulation Measurement Method As shown in FIG. 7A, infrared light from the light source unit 24 is introduced into the detector 22 through the sample cell unit 25 and introduced into the sample cell unit as the measurement means 5. In addition, a fluid modulation type NDIR that detects only a change in infrared absorption due to a measurement component in the sample gas is used. Since there is no modulation means such as a chopper in the optical system, the main force of the detector 22 becomes zero if there is no introduction or switching of gas to the sample cell, and infrared light inside the sample cell by the gas introduced into the sample cell. An output corresponding to the amount of change in absorption is obtained.

The operation and output at this time are shown in FIGS.
(1) As shown in FIG. 7B, the flow path R, the flow path Sa, and the flow path Sb are switched by the switching valve 7a, and the sample Sa-reference gas R-sample Sb-reference gas R is set at a constant period, for example, 2 Hz ( Switching at the modulation period) and introducing it into the measuring means 5.
(2) As shown in FIG. 7C, the detector output is an output obtained by mixing the output of the modulation period of 1 Hz and the output of 2 Hz.
(3) The detector output is rectified in synchronization with the modulation periods of 1 Hz and 2 Hz.
The output synchronized with the modulation period of 1 Hz means an average value of (NOx component concentration-NO component concentration) as shown in FIG. That is, it means the average value of the concentration of the NO ₂ component.
On the other hand, the output synchronized with the modulation period of 2 Hz means an average value of (NOx component concentration + NO component concentration) as shown in FIG.
(4) Therefore, by adding both outputs that are synchronously rectified to each modulation frequency, an output that is twice the concentration of the NOx component is obtained, and an output that is twice the concentration of the NO component is obtained by subtracting both outputs. Can do.
Above, it is possible to obtain a concentration of the NOx component / NO component / NO ₂ component.

  The measuring means 5 is not particularly limited as long as it has a method for detecting NO, and NDUV can be used in addition to NDIR. Moreover, it is possible to apply NDIR which has the solid state detector demonstrated in the 1st structural example also about NDIR.

<Basic functions of the analyzer according to the third configuration example>
Next, basic functions of the analyzer according to the third configuration example will be described.
The analysis apparatus according to the third configuration example introduces a sample containing the measurement component A into the conversion means X separately provided in the sampling system, detects the converted sample by the measurement means 5, and outputs the output A before and after the introduction. By comparing and calculating the output B before and after introduction, as in the second configuration example, (1) a calibration function for the measurement component A, and (2) a detection function for the measurement component A (a function for checking errors such as interference effects) are included. ), (3) processing function of the sample processing means (including the conversion function of the conversion means Y in this configuration example), (4) check of the processing function of the arithmetic processing means, and / or any one of the functions or Processing based on several combinations can be performed. The point that the function can be checked or processed during the sample measurement, the point that a plurality of functions can be checked or processed at the same time during the check or processing, and the like are the same as in the second configuration example.

(1) Check or process the calibration function of measurement component A,
(2) Checking or processing of the error checking function of the measurement target component A, and (3) Checking or processing of the conversion function of the converting means Y have the same basic functions as those of the second configuration example. The functions based on the characteristics of the two points (a) and (b) are different.
(A) The function of the measurement component A and the measurement component B based on the displacement from the reference value by detecting the reference gas R in addition to the sample Sa and the sample Sb at the time of actual sample measurement and check or processing It is possible to ensure higher measurement accuracy than the second configuration example in that it can be checked or processed.
(B) The unconverted measurement component A is measured by making it possible to measure again the sample that has passed through the flow path Sa, that is, the sample in which most of the measurement component A in the sample has been converted to the measurement component B. Therefore, the conversion efficiency of the conversion means Y can be calculated from the comparison between the first output A and the subsequent output A.

<Specific Checking Method and Processing Method of Analyzing Device According to Third Configuration Example>
Further, using the basic check or processing function of the above-described analyzer, specifically, the instrument calibration of the NO / NO ₂ analyzer, the conversion efficiency check of the conversion means, and the error inspection and correction method will be described in detail. .

The inspection of the conversion efficiency T of the converter 4a or the measurement accuracy of the NO ₂ component in this analyzer can be performed by the following method.
(1) Perform zero calibration and span calibration for the NO component in advance.
(2) A gas Z containing a predetermined amount of NO ₂ (regardless of concentration accuracy) is introduced from the sample inlet 1 as a sample gas.
The NOx component output and NO component output at this time are stored.
(3) Here, when the output of the NOx component is 90 ppm and the output of the NO component is 0 ppm, the conversion efficiency of the converter 4a is T. Therefore, the concentration of the NO ₂ component in the sample gas is 90 / T ( ppm).
(4: CHECK 1) Instead of the flow path Sa, the flow path R, the flow path Sc, and the flow path Sb are switched, and the reference gas R, the sample Sc, and the sample Sb are switched at a constant cycle and introduced into the measuring means 5.
(4-1) At this time, since the conversion efficiency of the converter 4c is Tx, the output of the NOx component is 90 / T × Tx (ppm) in calculation.
(4-2) Here, when the measured NOx component output is 95 ppm and the NO component output is 0 ppm, 90 / T × Tx = 95.
When Tx = 100%, T = 90 / (95 × 1.00) = 95%.
Further, the concentration of the NO ₂ component at this time is 90 / T = 95 (ppm).
This at the same time proves that the measurement function of the NO ₂ component is appropriate.
(5: CHECK2) The gas passing through the flow path Sa is introduced again from the sample inlet 1, and the flow path R, the flow path Sa, and the flow path Sb are switched by the electromagnetic valve 7 as in the normal measurement, and the reference gas R, the sample Sa, The sample Sb is switched at a constant cycle and introduced into the measuring means 5.
(5-1) At this time, since the conversion efficiency of the converter 4a is T, the output of the NOx component is 90 / T ² (ppm).
(5-2) Here, when the measured NOx component output is 95 ppm and the NO component output is 0 ppm, 90 / T ² = 95.
Therefore, T = √ (90/95) = 97%.
The initial concentration of the NO ₂ component is 90 / T = 93 ppm.
(6) Further, as a condition close to a sample to be actually measured, it is assumed that a sample having a NO component concentration of 50 ppm and a NO ₂ component concentration of approximately 50 ppm is measured.
Here, when the output of the NOx component is 90 ppm and the output of the NO component is 50 ppm, if the conversion efficiency of the converter 4a is T, the concentration of the NO ₂ component in the sample gas is (90-50) / T ( ppm).
(7: CHECK 1) Instead of the flow path Sa, the flow path R, the flow path Sc, and the flow path Sb are switched, and the reference gas R, the sample Sc, and the sample Sb are switched at a constant cycle and introduced into the measuring means 5.
(7-1) At this time, assuming that the conversion efficiency of the converter 4c is Tx, the output of the NOx component is calculated to be 40 / T × Tx (ppm).
(7-2) Here, when the measured NOx component output is 95 ppm and the NO component output is 50 ppm, 40 / T × Tx = 95-50.
When Tx = 100%, T = 40 / (95-50) = 89%.
Further, the concentration of the NO ₂ component at this time is 40 / T = 45 ppm.
(8: CHECK2) The gas passing through the flow path Sa is introduced again from the sample inlet 1, and the flow path R, the flow path Sa, and the flow path Sb are switched by the electromagnetic valve 7 as in the normal measurement, and the reference gas R, the sample Sa, The sample Sb is switched at a constant cycle and introduced into the measuring means 5.
(8-1) At this time, since the conversion efficiency of the converter 4a is T, the output of the NOx component is (90-50) / T ² (ppm).
(8-2) Here, when the measured NOx component output is 95 ppm and the NO component output is 50 ppm, 40 / T ² = 95-50.
Therefore, T = √ (40/45) = 94%.
The initial concentration of the NO ₂ component is 40 / T = 43 ppm.
(9) As described above, according to this analyzer, the conversion efficiency T of the converter 4a can be inspected by a simple method. Further, since the sample gas used above is a sample in actual operation and the same confirmation can be performed during measurement of the actual sample, NO ₂ substantially including the conversion efficiency T of the converter 4a. This means that the actual measurement accuracy of the component is being inspected. In other words, the apparatus has an excellent function of being able to inspect the actual measurement accuracy of the NO ₂ component without preparing a special span gas.

<Application of analyzer according to third configuration example>
The analyzer having the above-described configuration / function can be applied not only to the NOx analyzer using the conversion means for converting NO ₂ into NO, but also to the NOx analyzer and HC / CO / as in the second configuration example. The present invention can also be applied to various analyzers such as a CO ₂ analyzer.

  Further, in the above, the functions formed by the invention according to each claim have been described with reference to a configuration example in which a part of the functions is combined, but of course, the present invention is not limited to this, and other combinations, or Needless to say, any combination with the matters described in the present application is possible.

  The above describes the NOx analyzer in the atmosphere, but the same technique is applicable not only to other component analyzers in the atmosphere, but also to analyzers of specific components in exhaust gas or specific components in various plants and processes. The present invention can also be applied to analyzers, and the present invention can be applied not only to the measurement of gas as described above, but also to the measurement of components such as liquids and various measurement principles. Needless to say, it is not limited.

Explanatory drawing which illustrates the fundamental structure (1st structural example) of the analyzer which concerns on this invention. Explanatory drawing which illustrates schematically the measurement means of the analyzer which concerns on a 1st structural example. Explanatory drawing which illustrates schematically the other measuring means of the analyzer which concerns on a 1st structural example. Explanatory drawing illustrating another configuration (second configuration example) of the analyzer according to the present invention. Explanatory drawing illustrating another configuration (third configuration example) of the analyzer according to the present invention. Explanatory drawing which illustrates the operation | movement and output of the gas switching type | mold measuring method in a 2nd structural example. Explanatory drawing which illustrates the operation | movement and output of the fluid modulation type | mold measuring method in a 2nd structural example. Explanatory drawing which illustrates the structure of the analyzer which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sample inlet 2 Dust filter 3 Suction pump 4, 4a, 4c Conversion means (converter)
5 Measuring means 6 Flow path resistance 7 Solenoid valve (switching valve)
7a Switching valve 8 Calibration gas inlet Sa, Sb, Sc, R flow path

Claims (5)

An analyzer having a sampling system comprising a sample collection means, a sample processing means and a calibration means, a measurement means, and an arithmetic processing means, and is capable of detecting at least the concentrations of the measurement target component A and the measurement target component B,
A sample containing the measurement target component A is introduced into the conversion means X for selectively converting the measurement target component A separately provided in the sampling system into the measurement target component B, and the converted sample is detected by the measurement means; By comparing and calculating the output related to the measurement target component A of the measurement means before and after the introduction and the output related to the measurement target component B of the measurement means before and after the introduction,
Checking the detection function of the measurement target component A and / or the calibration function of the measurement target component A and / or the processing function of the sample processing means and / or the arithmetic processing means of the measurement means, and / or based on the function An analyzer characterized by performing processing. 2. The analyzer according to claim 1, wherein the measurement unit includes a detection unit that detects at least the concentration of the measurement target component A and a detection unit that detects the concentration of the measurement target component B.
An analyzer characterized by calibrating the measurement target component A of the measuring means by introducing the sample into the converting means X during the measurement and performing the comparison operation. The analyzer according to claim 2,
By introducing the sample into the conversion means X during the measurement and performing the comparison operation, an error with respect to the concentration of the measurement target component A including the influence of interference by other components in the sample on the output of the measurement target component A is corrected. Analyzing device characterized by doing.   The sample processing means has conversion means Y for selectively converting the measurement target component A into the measurement target component B, and the measurement means is configured by periodically switching between a sample that has passed through the conversion means Y and a sample that has not passed through the conversion means Y. 2. The analyzer according to claim 1, wherein the concentration of the measurement target component A and the measurement target component B is detected by the measurement unit having at least a detection unit that detects the concentration of the measurement target component B. Is introduced into the conversion means X during the measurement, and the comparison operation is performed to check the conversion efficiency of the conversion means Y and replace the conversion means X when the efficiency is reduced.   Gas switching measurement method or fluid in which the sample processing means has a reference gas supply flow path, a flow path having the conversion means Y, and a flow path not having the conversion means Y, and switching between the three flow paths 5. The analyzer according to claim 1, wherein a modulation type measurement method is used.

Images