JPH01174962A - Fluid analyzer for three component simultaneously continuous measurement using differential method and multiple fluid modulation method - Google Patents

Abstract

PURPOSE:To achieve a smaller size of the apparatus, by measuring a single and a total concentration of first and third components to determine a single concentration of a second component from a difference in the results of measurement. CONSTITUTION:A sample fluid S comprises first and second fluids S1 and S2 being shunted into two passages. The passage of the fluid S1 measures a single component of a first component (CH4) in the fluid S1 with a converter C to burn away a second component (HC) in fluid S1 while the passage of the fluid S2 makes a line to measure the concentration of a third component (total HC). After the modulation with comparison fluids R1 and R2 by frequencies F1 and F2 using fluid modulation means V1 and V2, the fluid S1 and S2 converted are supplied to a detector D. A signal O outputted from the detector D is separated into signal components O1 and O2 with the modulation frequencies F1 and F2 relative to the fluids F1 and F2 by a signal processing means B and a signal processing is performed to obtain the results of measuring the first and third components. This enables measurement of a single concentration of the second component (non-methane HC) from a difference between the results of measuring both the concentrations.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a first and a second component (for example, CH, Other non-methane HC, or
NO, NO8, etc.) and the third component (total HC or total No.) defined as the sum of both components, the concentration of the third component (total HC, etc.)
concentration or total concentration) and the individual concentration of the first component (CHa concentration or NO concentration) are directly measured by the same type of detector (HC detector or NO detector), while both of them are By using the so-called differential method of indirectly measuring the independent concentration of the second component (non-methane HC concentration or No! concentration) from the difference in concentration,
It relates to a fluid analyzer for simultaneous and continuous measurement of three components, which is configured to be able to simultaneously and continuously measure the concentrations of the three components, and more specifically, for such a fluid analyzer for simultaneous and continuous measurement of three components, a multi-fluid modulation method is used. (This is the name given by the inventors) By applying a unique method that has never existed before, these three components can be detected simultaneously while using only one detector, which is less than before. This invention was developed with the aim of providing a completely new fluid analysis device that can perform continuous analysis.

[Conventional technology]

For example, the sample fluid contained in the atmosphere is an example of a sample fluid.
When performing fluid analysis to analyze the concentration (and thus the amount) of harmful components (especially non-methane HC and NOt) in automobile exhaust gas, factory exhaust gas, etc., the differential method as described above is used. A fluid analyzer for simultaneous and continuous measurement of three components is used, but in order to achieve this with a conventional general fluid analyzer for simultaneous measurement of three components, it is necessary to detect the concentration of the third component (total concentration). Two detectors (sensors) were required: a detector and a detector for detecting the concentration of the first component alone.

That is, when continuously measuring non-methane HC (second component), which is a particularly harmful component among the HC components in the sample fluid, the sample fluid S is divided into two streams as shown in Figure 7 (a). The first sample fluid S1 and the second sample fluid S2 are divided into the channels, and one channel is provided with a catalyst for burning and removing only the non-methane HC (second component) in the first sample fluid S1. A first HC detector DI (for example, a flame ion detector) for measuring the concentration of CHa (first component) in the converted first sample fluid 31 by inserting a converter C consisting of a device, etc. First analysis section A1 with detector: FID)
is provided, and the other flow path is not provided with a converter as described above, and the total HC concentration in the second sample fluid S (
a second analysis section A having a second HC detector D2 (also a flame ion detector: FID) for measuring the concentration of the third component as the sum of the first component and the second component;
2, and so on, two analysis sections Al are provided.

A2 and HC detector D1. D2 is required.

The independent concentration of non-methane HC as the second component is determined from the third component concentration (total HCt 11 degrees) obtained by the second signal processing circuit B2 connected to the second HC detector D1 of the second analysis section A2. , a first signal processing circuit B1 connected to the first HC detector D1 of the first analysis section A1.
It can be obtained as an output from a subtraction circuit G that performs subtraction processing on the first component single concentration (CHs concentration) obtained by.

In addition, when continuously measuring N07 (second component), which is a particularly harmful component of NOo in the sample fluid, as shown in Figure 7 (b), the sample fluid S is divided into two channels. The flow is divided into a first sample fluid S1 and a second sample fluid S2, and one flow path is subjected to a (reduction) process to convert No. (second component) in the first sample fluid S1 into No. (first component). By installing a converter C consisting of a catalytic device and the like for converting, the total concentration of the third component in the converted first sample fluid Sl is 081 degrees (the concentration of the third component as the sum of the first component and the second component). ) is provided with a first analysis section A1 having a first NO detector Di (for example, a chemical luminescence detector: CLD) for measuring the A second analysis section A having a second NO detector D2 (also a chemical luminescence detector: CLD) for independently measuring the No (first component) concentration in S
2, and so on, two analysis sections A1. A2 and NO detector DI, O2 are required. Note that the second
The individual concentration of NO8 as a component is determined by the first analysis section A1.
A first signal processing circuit B connected to the first NO detector D1 of
From the third component concentration (total concentration) obtained in step 1, the first component alone concentration (No concentration) obtained by the second signal processing circuit B2 connected to the second NO detector D2 of the second analysis section A2 is calculated. It can be obtained as an output from the subtraction circuit G that performs subtraction processing.

[Problem that the invention seeks to solve]

However, as described above, the first component and the second component are similar components contained in the same sample fluid, and
When performing simultaneous and continuous analysis of the three components of the third component, which is defined as the sum of both components, it is necessary to use two detectors (sensors) and an analysis section as in the conventional apparatus described above. A) Not only does the analyzer become larger and the manufacturing cost becomes higher, but also (b) Since adjustments such as zero and span adjustments are required for each of the two detectors, the time and effort required for measurement becomes large. (1) Each detector is not adjusted sufficiently and there is a zero adjustment error or sensitivity difference between the two detectors, or
Mutual interference often occurs between the two detectors, leading to various problems such as very large measurement errors.

Therefore, in order to avoid such problems, two components (the first component and the third component) in the same sample fluid are alternately measured using a fluid analysis device equipped with only one detector. It may be possible to use a so-called batch processing analysis method, but in that case, simultaneous and continuous measurements cannot be performed, so the measurement data will be discontinuous, and the concentration measurement results of the first component and the third component will be discontinuous. Since there is a time difference between the result of measuring the concentration of the second component and the result of measuring the concentration of the second component, there is a drawback that the reliability of the result of measuring the concentration of the second component obtained by calculating the difference between them is greatly inferior. Therefore, adopting such a batch analysis method simply to save on the number of detectors may greatly sacrifice the original purpose of fluid analysis, and is not a good idea. .

The present invention has been made in view of the above-mentioned conventional situation, and its purpose is to provide a simple and inexpensive structure that uses only one detector, which is smaller than the conventional one, and yet to be able to detect The object of the present invention is to develop a fluid analyzer for simultaneous and continuous measurement of three components, which can analyze the three components described above simultaneously and continuously with high precision.

[Means for solving problems]

In order to achieve the above object, the present invention has the following features:
As is clear from the basic conceptual diagrams (diagrams corresponding to claims) shown in (b), the sample fluid S is configured to be divided into two flow paths as a first sample fluid S1 and a second sample fluid S2, and the above-mentioned The flow path of the first sample fluid S1 is designed to either remove the second component in the first sample fluid S1 as shown in FIG. By installing a converter C for conversion, it becomes a line for measuring the concentration of the first component alone or a line for measuring the concentration of the third component (total concentration). Without setting, third component concentration (total concentration)
A measurement line or a line for measuring the concentration of the first component alone, and the converted first sample fluid Sl and the unconverted second sample fluid S2 are used as comparison fluids R1 and R2, respectively.
The frequencies Fl are different from each other.

Fluid modulation means Vl for fluid modulation at F2 (Hertz)
, V2 are provided in both the flow paths, have only one detector capable of detecting both the concentration of the first component and the concentration of the third component, and have fluid modulation in each of the flow paths. Both sample fluids 31.3
2 is provided simultaneously and continuously, and the output signal O from the detector in the analysis section A is adjusted to each modulation frequency Fl, F2 (Hertz) for each sample fluid S1.32. By separating the signal components into 01.02 and rectifying and smoothing them, the first
Single concentration of component and concentration of third component (total concentration)
The multi-fluid has the following characteristics: a signal processing means B is configured to be able to measure each of the second components separately, and to be able to measure the individual concentration of the second component from the difference between the two concentration measurement results. The present invention provides a fluid analyzer for simultaneous and continuous measurement of three components using a modulation method and a differential method.

[Effect]

The effects achieved by this characteristic configuration are as follows.

That is, in the fluid analyzer for simultaneous and continuous measurement of three components using the differential volume method and multi-fluid modulation method according to the present invention, the sample fluid S is The first sample fluid s1 is divided into a first sample fluid S1 and a second sample fluid S2, and the first sample fluid s1 is processed to remove the second component therein or convert it into the first component. In a fluid analyzer equipped with a basic configuration for simultaneous and continuous measurement of three components, in which the second sample fluid S2 is supplied to the analysis section A from the first sample fluid S1- And the second sample fluid S2 is adjusted to the comparative fluids R1 and R using appropriate fluid modulation means vi and V2, respectively, which are constituted by, for example, rotary pulp, a three-way switching solenoid valve, a four-way switching solenoid valve, etc.
2, the fluids are modulated at different frequencies Fl and F2, respectively, and then simultaneously and continuously supplied to the analysis section A having only one detector.
The conventional wisdom is that a single measurement signal 0 (=01+02) is obtained from multiple detectors, in which the individual measurement signal components (01, 02) corresponding to both sample fluids 31 and 32 are collectively superimposed. We adopted a unique method (multi-fluid modulation method) that was completely unthinkable, and made the output signal 0 from the single detector, for example, in Fig. 1 (a).

As schematically illustrated in (b), by using the signal processing means B constructed by appropriately combining a frequency separation means, a signal rectification/smoothing means, and a subtraction means, it is possible to Each modulation frequency F1. F2
By performing signal processing of separating signal components 01.02 into signal components 01.02 and rectifying and smoothing them, the analysis values for each sample fluid 31.32, that is, the first
(3) Obtain the measurement results of the component concentration and the third (1) component concentration, and further calculate the difference between the third component concentration (total concentration) obtained in this way and the first component alone concentration. Since it is configured to obtain the measurement result of the independent concentration of the second component, it is defined as the first component and the second component, which are similar components contained in the sample fluid S, and the sum of these two components. When performing simultaneous and continuous analysis of the third component, it is only necessary to provide one analysis section A and a detector (sensor). Compared to a fluid analysis device for measurement, the entire device can be made smaller, simpler, and cost-effective, and the detector can be adjusted easily and in a shorter time. Since zero adjustment errors, sensitivity differences, or mutual interference between instruments cannot occur, good measurement accuracy can always be ensured.

〔Example〕

Specific embodiments of the present invention are shown below in the drawings (Figures 2 to 7).
The explanation will be based on Figure).

2 to 4 show an HC concentration analyzer as an example of a fluid analyzer for simultaneous and continuous measurement of three components using the differential method and multi-fluid modulation method according to the first embodiment. This means that, for example, among the HC components contained in the sample fluid S such as the atmosphere, automobile exhaust, or factory exhaust,
It is used in cases where the concentration of non-methane HC (second component), which is a particularly harmful component, is to be analyzed. The concentration of the third component (total HC concentration) defined as the sum of the second image components is directly measured, and the individual concentration of nonmethane HC, which is the second component, is indirectly measured from the difference between the two concentration measurement results. It is said to be composed of

Now, as shown in the overall schematic configuration diagram of FIG. 2, the sample fluid S is configured to be divided into two flow paths as a first sample fluid S1 and a second sample fluid S2, and the 1 sample fluid S10 flow path contains non-methane H, which is the second component in the first sample fluid S1.
By installing a converter C consisting of a catalyst device etc. for burning and removing C, it becomes a line for measuring the independent concentration of methane (CH4), which is the first component,
On the other hand, the flow path for the second sample fluid S2 is configured to be a line for measuring the third component concentration (total HC concentration) without providing a converter as described above.

A first sample fluid S1 that has been converted (that is, non-methane HC has been removed and contains only methane as HC) and a second sample fluid S2 that has not been converted (that is, non-methane Both sample fluids 31 and 32 (same as the original sample fluid S containing both HC and methane) were, respectively,
Using fluid modulation means Vl, V2, comparison fluid R1, R2
(Typically zero gas is used) due to the different frequencies Fl, F2 (Hertz) (in this example, F1=
In other words, the sample fluid and the comparison fluid were passed alternately at a predetermined frequency), and each of the fluid-modulated sample fluids 31.S
2 (R1, R2) are simultaneously and continuously supplied to the analysis section A having only one detector D (sensor). In this case, the detector in the analysis section A is generally of a type through which the sample fluid passes directly, such as a flame ion detector (FID) for HC detection. Both sample fluids modulated St.

32 (R1, R2) are supplied to the detector in a mixed state.

Therefore, the signal 0 outputted from the detector via the preamplifier 2 has individual measurement signal components (0
1,02) are collectively superimposed on one measurement signal (0
-01+02).

Therefore, the output signal 0 from the detector is converted into a signal constructed by combining frequency separation means E, signal rectification means F, and subtraction means G, as conceptually illustrated in FIG. By using the processing means B, signal processing is performed to separate signal components 01.02 of each transformation frequency Fl and F2 for each of the sample fluids SL and S2, and to perform rectification processing and smoothing processing on each signal component, respectively. The analysis value regarding the fluid 31, S2, that is, the first component -
(Methane) and the concentration of the third component (total HC concentration) can be obtained separately and directly, and the second component (Methane) is calculated from the difference between the two concentration measurement results. It is configured so that the single concentration of non-methane HC) can be measured indirectly.

The specific circuit configuration of the signal processing means B is as follows.
The circuit configuration is as shown in the block circuit diagram in the figure.

That is, the signal 0 outputted from the detector via the preamplifier 2 is branched into two signal processing lines arranged in parallel, and one signal processing line has a modulation frequency F1 for the sample fluid S1. A band pass filter a1 is provided to separate and extract (pass) only the signal o1 of (IH2), and at the subsequent stage, synchronization from a synchronization signal generator 1a attached to the fluid modulation means v1 for the sample fluid S1 is provided. The signal (signal representing the actual fluid modulation operation by the fluid modulation means v1: IHz) supplements the frequency separation effect that may be insufficient with the bandpass filter al alone, and achieves even more accurate frequency separation. At the same time, a synchronous detection rectifier b1 is provided for synchronously rectifying the output signal 01 from the bandpass filter a1 so that the separated alternating current can be converted into direct current. A low-pass filter (L,
P, F), and the other signal processing line is provided with a bandpass filter a2 for separating and extracting (passing) only the signal 02 of the modulation frequency F2 (2 Hz) for the sample fluid S2, In the subsequent stage,
A synchronizing signal (fluid modulating means v) from a synchronizing signal generator lb attached to the fluid modulating means v2 for the sample fluid S2
The signal representing the actual fluid modulation operation by 2H2) supplements the frequency separation effect that may be insufficient with the bandpass filter a2 alone, and enables even more accurate frequency separation. The band pass filter a2
A synchronous detection rectifier b2 is provided for synchronously rectifying the output signal o2 from the synchronous detection rectifier b2, and a smoothing element c2 is provided at the subsequent stage for smoothing the output signal from the synchronous detection rectifier b2 and removing frequency noise. low-pass filters (L, P, F) are provided, and the sample fluid S1
A subtracter G is provided as a subtraction means for manually inputting the output signal from the smoothing element C1 in the signal processing system related to the sample fluid S2, and manually inputting the output signal from the smoothing element C2 in the signal processing system related to the sample fluid S2. It is something. Therefore, the smoothing element cl outputs the measurement result of the concentration of methane, which is the first component, and the measurement result of the concentration of the third component (total HC concentration) is output from the smoothing element c2. , the subtracter G outputs the measurement result of the independent concentration of nonmethane HC, which is the second component.

The signal processing means B is a computer capable of performing numerical analysis processing such as Fourier analysis (corresponding to frequency separation processing), absolute value averaging processing (corresponding to rectification/smoothing processing), and subtraction processing. It is possible to configure it by appropriate means using various software or hardware, such as using a lock-in amplifier and a subtracter, or using other electric circuit configurations such as a lock-in amplifier and a subtracter.
In particular, in the device of the present invention, as described above, two signal processing series are provided in parallel, each consisting of bandpass filters al, a2, synchronous detection rectifiers bl, b2, and smoothing elements cl, c'l connected in series. Since the configuration is very simple and inexpensive compared to the above-mentioned means using a computer or lock-in amplifier, etc., there is also a possibility that bandpass filters Al and A2 alone may not be sufficient. The synchronous detection rectifier b1. Since the configuration is such that more accurate frequency separation can be performed by supplementing with b2, for example, compared to a configuration in which absolute value rectification is performed immediately after frequency separation using only a bandpass filter, There is an advantage that significantly superior signal processing performance (SZN ratio) can be obtained.

By the way, as long as each of the fluid modulation means Vl (V2) can alternately switch between the sample fluid 5l (32) and the comparison fluid R1 (R2) at a predetermined frequency,
Its configuration is arbitrary; for example, it may be configured with a rotary valve as shown in Figure 4 (a), or it may be configured with a four-way switching solenoid valve as shown in Figure 4 (b). Although not shown, a three-way switching solenoid valve may also be used.

FIGS. 5 and 6 show a NOx concentration analyzer as an example of a fluid analyzer for simultaneous and continuous measurement of three components using the differential method and multi-fluid modulation method according to the second embodiment. This is also used, for example, when analyzing the concentration of Not (second component), which is a particularly harmful component among NOX components contained in a sample fluid S such as the atmosphere, automobile exhaust, or factory exhaust. For that purpose, the first
The individual concentration of the component No, and their first . Second
A configuration in which the density of the third component (total N Otl 1 degree) defined as the sum of the image components is directly measured, and the individual density of Not, which is the second component, is indirectly measured from the difference between the two density measurement results. has been done.

In the case of this second embodiment device, as is clear from the overall schematic diagram of FIG.
In addition to using a catalytic device to convert (reduce) No. 8 into No. 8, which is the first component, a chemical luminescence detector (CLD
) and other NO detectors are used.

Therefore, in this case, the flow path of the first sample fluid S1 becomes a line for measuring the third component concentration (total N Otla degree) in the first sample fluid S1, and the flow path of the second sample fluid S2 The line serves as a line for measuring the independent concentration of No, which is the first component, and as is clear from the block circuit diagram of the signal processing means B shown in FIG. 3rd from C1
The measurement results of component concentration (total concentration) are output,
Further, the measurement result of the single concentration of No, which is the first component, is output from the smoothing element C2 of the system of the first sample fluid S1,
Then, the subtracter G outputs the measurement result of the independent concentration of NOx, which is the second component.

The other configurations of this second embodiment are the same as those of the first embodiment, so members having the same functions are designated by the same reference numerals, and the explanation thereof will be omitted.

It should be noted that the present invention is not limited to the above-mentioned re-embodiments, but includes, for example, Cox (Co, Cot, total).

It goes without saying that it is also applicable to other types of three-component measurements such as C).

〔Effect of the invention〕

As is clear from the above detailed description, according to the fluid analyzer for simultaneous and continuous measurement of three components using the differential volume method and multi-fluid modulation method according to the present invention, the sample fluid is separated into the first sample fluid and the second sample fluid. Along with dividing the fluid into
The first sample fluid is processed by a converter to remove the second component or convert it into the first component before being supplied to the analysis section, while the second sample fluid is supplied to the analysis section as is. For a fluid analyzer equipped with a basic configuration for simultaneous and continuous measurement of three components, the first sample fluid and the second sample fluid are adjusted to be different from each other depending on the comparison fluid using a fluid modulation means, respectively. By modulating each fluid with a frequency and then simultaneously and continuously feeding it into an analysis section having only one detector, the individual measurements corresponding to both sample fluids are first obtained from that single detector. A unique multi-fluid modulation method is applied to obtain a single measurement signal in which signal components are superimposed all at once, and the output signal from the single detector is subjected to appropriate frequency separation means and signal rectification/smoothing. By using a signal processing means configured by combining means and subtraction means, signal processing is performed in which signal components of each modulation frequency for each sample fluid are separated and rectified and smoothed respectively. obtaining analytical values for each sample fluid, that is, measurement results of the concentration of the first (3) component and the concentration of the third (1) component;
Furthermore, by calculating the difference between the third component concentration (total concentration) obtained in this way and the first component alone concentration, the measurement result of the second component alone concentration is obtained.
Although it can be configured very simply and inexpensively by providing only one analysis section and detector (sensor), it is possible to analyze the first and second components, which are similar components contained in the sample fluid, and their It is now possible to perform simultaneous and continuous analysis of the third component, which is defined as the sum of image components. In comparison, the entire device can be made smaller, simpler, and cost-reduced, and the detector can be adjusted more easily and in a shorter time. Alternatively, since mutual interference cannot occur, a remarkable effect is exhibited in that good measurement accuracy can always be ensured.

[Brief explanation of the drawing]

Figures 1 (a) and (b) are explanatory diagrams (diagrams corresponding to claims) of the basic concept of a fluid analyzer for simultaneous and continuous measurement of three components using the differential volume method and multi-fluid modulation method according to the present invention, respectively.
It shows. 2 to 6 show various specific embodiments of the device of the present invention, FIG. 2 is a general schematic diagram of the first embodiment, FIG. 3 is a block circuit diagram of its signal processing means, 4(a) and 4(b) are respectively schematic illustrations of the fluid modulation means, FIG. 5 is an overall schematic diagram of the second embodiment, and FIG. 6 is a block circuit diagram of the signal processing means. It is a diagram. FIGS. 7(a) and 7(b) are for explaining the technical background of the present invention and the problems of the prior art, and show the fluid analysis for simultaneous and continuous measurement of three components according to the conventional example, respectively. 1 shows an overall schematic configuration diagram of the device. S: Sample fluid, Sl: First sample fluid, S2: Second sample fluid, R1, R1 comparison fluid, Fl, F2: Modulation frequency, Vl, F2: Fluid modulation means A: Analysis section, D: Detector, B : Signal processing means, C: Converter, 0: Output signal from the detector, 01.02: Each sample fluid 31. Each modulation frequency Fl for S2°. F2 signal component. Applicant Horiba Manufacturing Co., Ltd. Representative Patent Attorney Hideo Fujimoto

Claims (1)

[Claims] Regarding the first component and the second component, which are similar components contained in the sample fluid, and the third component defined as the sum of both components, the concentration of the third component (total concentration) By using a so-called difference method in which the individual concentration of the second component and the individual concentration of the first component are directly measured using the same type of detector, and the individual concentration of the second component is indirectly measured from the difference between the two concentrations, In a fluid analyzer for simultaneous and continuous measurement of three components, which is configured to be able to measure the concentration of three components simultaneously,
The sample fluid is configured to separate into two flow paths as a first sample fluid and a second sample fluid, and the flow path for the first sample fluid removes a second component in the first sample fluid. Alternatively, a converter for converting the fluid into the first component is inserted to create a line for measuring the concentration of the first component alone or a line for measuring the concentration of the third component (total concentration), and the flow path for the second sample fluid is as described above. A third component concentration (total concentration) measurement line or a first component single concentration measurement line is used without providing a converter, and the converted first sample fluid and the unconverted second sample fluid are connected to each other using a comparison fluid. Fluid modulation means for modulating the fluid at different frequencies is provided in both channels, and has only one detector capable of detecting both the concentration of the first component and the concentration of the third component, and An analysis section is provided to which both sample fluids each fluid-modulated are simultaneously and continuously supplied in a flow path, and the output signal from the detector in the analysis section is converted into signal components of each modulation frequency for each sample fluid. By separating and rectifying and smoothing each component, the individual concentration of the first component and the concentration of the third component (total concentration) can be measured separately, and the difference between the two concentration measurement results can be used to determine the concentration of the first component and the third component (total concentration). A fluid analysis device for simultaneous and continuous measurement of three components using a differential method and a multi-fluid modulation method, characterized in that the device is provided with a signal processing means configured to be able to measure the concentration of a second component alone.