JPH06103258B2 - Fluid analysis device by multi-fluid modulation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention adopts a unique non-conventional method called a multi-fluid modulation method (this is the name named by the present inventors). 2 (or shunted into 2 systems) while using only 1 detector
Mutual interference between the two sample fluids in order to obtain even higher measurement accuracy in a completely new fluid analysis device capable of simultaneously and continuously analyzing the sample fluids with extremely high accuracy. It was made as a development of a mechanism to correct the measurement error due to.

[Conventional technology]

For example, harmful components such as automobile exhaust gas and factory exhaust gas (NO _x , H
Fluid analyzers used to analyze the concentration (and thus the amount) of _y C _z or CO _x etc. have traditionally included analyzers equipped with a chemical luminescence detector (CLD) or frame analyzers. An analyzer equipped with an ion detector (FID), or a non-dispersive infrared analyzer (NDIR) equipped with a condenser type microphone or a micro flow type pneumatic detector or a solid detector such as a thermopile or a semiconductor. Fluid analyzers that employ various detectors (sensors) are used.

By the way, when performing the fluid analysis as described above, for example, NO and NO ₂ , or methane (CH ₄ ) and HC other than methane (NMHC), or CO and CO ₂ ,
In many cases, it is necessary to measure the concentrations of two components in the sample fluid simultaneously and continuously, but in order to realize it with conventional general fluid analyzers, two detectors (sensors) are inevitably required. Met.

That is, in the case of simultaneously measuring NO and NO ₂ simultaneously, the sample fluid is divided into two measurement systems, and one system is a first NO detector for measuring the NO concentration in the sample gas by itself. And the other system is provided with a _second NO detector for measuring the total NO concentration in the processed fluid produced by converting the NO ₂ in the sample gas into NO. NO detector is required (NO ₂ concentration is obtained as the difference between the total NO concentration detection value by the _second NO detector and the NO single concentration detection value by the first NO detector, and this method is called the difference method) When measuring methane and HC other than methane (NMHC) at the same time, split the sample fluid into two measurement systems, and use one system to divide the total HC concentration (TH
To measure the concentration of methane in the process gas produced by the first HC detection to measure C), and the other system is subjected to the process of catalytically removing HC other than methane in the sample fluid by catalytic combustion. 2 HC detectors are required, such as installing the 2nd HC detector (in this case, the difference method is also used, and NMHC uses the THC concentration detection value from the 1st HC detector and the 2nd HC detector) Obtained as the difference with the detected value of methane concentration),
When measuring CO and CO ₂ in the sample fluid simultaneously and continuously, the sample fluid is divided into two measurement systems, one system is equipped with a CO detector and the other system is equipped with a CO ₂ detector. , Two different detectors are required, a CO detector and a CO ₂ detector.

Then, as described above, by dividing the same sample fluid into two systems, it is not limited to the case where two components in the sample fluid are simultaneously and continuously analyzed, and two different sample fluids are included in each. It is apparent that two detectors (sensors) are also required when attempting to perform simultaneous and continuous analysis of specific components.

However, as described above, when performing the simultaneous continuous analysis of two components in the same sample fluid or the specific component contained in each of two different sample fluids, as in the conventional device, The fact that two detectors must be used not only means that (a) the analyzer becomes large and the manufacturing cost is high, but (b) zero detector and span adjustment for each two detectors. Since adjustment is required, it is very troublesome for measurement and is very troublesome. (C) When the adjustment of each detector is not sufficient and there is a zero adjustment error or a difference in sensitivity between the two detectors. Causes various problems such as a very large measurement error.

Therefore, in order to avoid such a problem, an analyzer equipped with only one detector is used to alternately measure two components in the same sample fluid, or alternatively two different sample fluids are alternately measured. It may be possible to use a batch-type analysis method, which is a measure to measure in the same way, but in that case, there is a disadvantage that the measurement data becomes discontinuous because simultaneous and continuous measurement cannot be performed. When performing the analysis using the difference method, there is a possibility that the measurement accuracy may be significantly deteriorated. Therefore, it is not a good idea to adopt such a batch-type analysis method merely to save the number of detectors, because it may seriously sacrifice the original purpose of fluid analysis.

In view of such conventional circumstances, the inventors of the present invention have, as a result of earnest research, adopted an epoch-making method called a multi-fluid modulation method, thereby using only one detector, (Or split into multiple systems)
We have developed a completely new fluid analysis method and fluid analysis device that can analyze sample fluids simultaneously and continuously. For the basic concept, see 1987.
We have already proposed it based on earlier applications such as the patent application filed on December 11, and the patent application filed on December 12, 1987.

That is, the fluid analysis device by the multi-fluid modulation method (the method is applied in this device) is shown in the basic conceptual diagram shown in FIG. 3 and the specific configuration diagram of the main part shown in FIG. As is apparent from the above, a plurality (two in this example) of sample fluids S1 and S2 (these may be different from each other originally, or a single sample fluid may be divided into two systems) Respectively,
Fluid modulation means V1 and V2 for performing fluid modulation at different frequencies F1 and F2 (Hertz) by comparison fluids R1 and R2, and a single detector D, and the fluid-modulated sample fluids S1 and S2. Are supplied simultaneously and continuously, and an output signal O from the detector D in the analysis unit A.
To the signal components O1 and O2 of the modulation frequencies F1 and F2 for the sample fluids S1 and S2 by appropriately using frequency separating means and signal rectifying / smoothing means (which is conceptually shown in FIG. 3). It comprises a signal processing means B for obtaining an analysis value for each of the sample fluids S1 and S2 by separating and performing rectification and smoothing respectively, and further, the signal processing means B is configured as shown in FIG. As specifically shown in FIG. 1, from the output signal O from the detector D,
Two band pass filters a1 and a2 that pass only signals in the bands near F1 and F2 are provided in parallel with each other, and the pass band frequency F1 (F2) is provided after the band pass filters a1 (a2). Fluid modulation means V1 (V2) corresponding to
The synchronous detection rectifier b1 (b2) for detecting and rectifying the output signal from the bandpass filter a1 (a2) is provided in synchronization with the actual fluid modulation operation by, and the subsequent stage of each synchronous detection rectifier b1 (b2). In addition, the smoothing element c1 (c2) for smoothing the output signal therefrom is provided.

That is, in the fluid analysis apparatus of the multi-fluid modulation system having such a configuration, the comparison fluid is compared by using the appropriate fluid modulation means V1 and V2 configured by, for example, a rotary valve, a three-way switching solenoid valve or a four-way switching solenoid valve Two sample fluids S1 and S2 that are fluid-modulated by R1 and R2 at different frequencies F1 and F2, respectively (or divided into two systems)
By simultaneously and continuously supplying to the analysis section A having only one detector D, the individual measurement signals corresponding to all the sample fluids S1 and S2 are first obtained from that one detector D. In addition to adopting a peculiar method that was not considered at all by conventional wisdom, that one measurement signal O (= O1 + O2) in which components (O1, O2) are collectively superimposed is obtained.
Next, the output signal O from the only one detector D is signal processing means B which is constituted by appropriately combining frequency separation means and signal rectification / smoothing means as illustrated in FIG. By using each sample fluid S
By performing signal processing of separating the signal components O1 and O2 of the respective modulation frequencies F1 and F2 for 1, S2 and performing rectification and smoothing processing respectively, it is possible to obtain analysis values for the sample fluids S1 and S2. Therefore, even when performing simultaneous continuous analysis of two components in the same sample fluid or simultaneous analysis of a specific component contained in each of two different sample fluids, only one detector ( Therefore, it is possible to reduce the size and simplification of the entire device and to reduce the cost more easily than the conventional general fluid analysis device that requires two detectors. It is easy to adjust in a short time, and since zero adjustment error and sensitivity difference between multiple detectors cannot occur unlike the conventional method, it is always possible to ensure good measurement accuracy. Has excellent advantages.

Moreover, as the signal processing means B, for example, a computer capable of arithmetic processing of numerical analysis such as Fourier analysis (corresponding to frequency separation processing) and absolute value averaging processing (corresponding to rectification / smoothing processing) is used. Alternatively, it is possible to configure appropriate means by various software or hardware such as using an electric circuit such as a lock-in amplifier. In the above fluid analyzer, as shown in FIG. , Bandpass filter a1
(A2), the synchronous detection rectifier b1 (b2), and a smoothing element c1 (c
2) The signal processing series formed by connecting in series with is provided in parallel in two columns, so it is very simple and inexpensive compared to the above-mentioned means using a computer or a lock-in amplifier. Of course, the band-pass filter a1 (a2) alone is used to supplement the frequency separation action that may be insufficient by the synchronous detection rectifier b1 (b2) so that more accurate frequency separation can be performed. Therefore, for example, compared with the configuration in which absolute value rectification is performed immediately after frequency separation using only a bandpass filter, the signal processing performance (S / N) is far superior.
There is also an advantage that the ratio can be obtained.

However, even in the fluid analysis device by the multi-fluid modulation method, which has various useful advantages as described above,
The following problems remain.

That is, as described with reference to FIG. 4, in the signal processing means B, the measurement signal O input from the detector D via the preamplifier 2 is first filtered by the bandpass filters a1 and a2. The individual measurement signal components O1 (frequency F1) and O2 (frequency F2) corresponding to the sample fluids S1 and S2 are separated, but it is necessary to set both fluid modulation frequencies F1 and F2 to sufficiently different values. Alternatively, it is not possible to obtain a reliable frequency separation result without practically difficult measures such as using a high-grade one having considerably sharp frequency cut characteristics as both bandpass filters a1 and a2. Therefore, in addition to the signal O1 of the original frequency F1 (F2), the noise component of the other fluid modulation frequency F2 (F1) is inevitably mixed in the signal that has passed through each bandpass filter a1 (a2). The mutual interference effect that it does will occur.

Thus, if the noise component of the other fluid modulation frequency F2 (F1) due to the mutual interference effect is mixed in the signal that has passed through each band pass filter a1 (a2), the following inconvenience occurs. .

That is, the both fluid modulation frequencies F1 and F2 can usually be arbitrarily set, but in that case, in general, even after the signal is synchronously detected and rectified by the synchronous detection rectifier b1 (b2). A signal corresponding to the interference noise component remains as a measurement error factor (that is, its smoothed value does not become 0).

This will be easily understood from FIGS. 5 (a) and 5 (b) showing an example in which one fluid modulation frequency F1 is 1 Hz and the other fluid modulation frequency F2 is 3 Hz. .

It should be noted that the measurement error factors due to the mutual interference effect as described above appear extremely greatly in a system using a low-frequency signal as a measurement signal, as is clear from FIG. 5 (a). As is apparent from (b), it does not appear so large in a system in which the higher frequency signal is the measurement signal (that is, the lower frequency signal is measured from the system side in which the higher frequency signal is the measurement signal). It has been experimentally found that there is a tendency that interference to the system side as a signal) is large, and it can be theoretically verified from the graphs of FIGS. 5 (a) and 5 (b). it can.

Further, the above problem is not limited to the noise component due to the mutual interference effect, and for example, the frequency F2 (of the other system) caused by other factors such as the deviation of the mechanical duty of the fluid modulation unit V1 (V2) ( The same occurs when the noise component of F1) is mixed.

Therefore, in order to reduce the above “measurement error caused by the interference noise component or the like of the other frequency signal in the system using one frequency signal as the measurement signal” as described above, As a result of continued research, we have developed the following technology, which we have already proposed in a patent application filed on December 24, 1987.

In the fluid analysis device by the multi-fluid modulation method having the above-mentioned basic structure, as shown in FIG. 6, the two fluid modulation means V1 and V2 have the ratio of the fluid modulation frequencies F1 and F2. Set to be even or even 1 / F1 (F1 = lHz, F2 = 2hlHz or vice versa: h
Is an integer).

That is, by adopting such a configuration, for example, both fluid modulation frequencies V1 and V2 are set to sufficiently different values, or sharp frequency cut characteristics are provided as both band pass filters a1 and a2 in the signal processing means B. Without using practically difficult means such as using a high-grade one, it is easy to eliminate measurement errors, etc. due to interference noise components due to local frequency signals in the system that uses one frequency signal as the measurement signal as described above. Can be reduced to

That is, for example, one (lower) fluid modulation frequency F1
When the fluid modulation frequency F2 of 1 Hz and the other (higher) is set to 2 Hz, which is an even multiple (double) of that, the lower frequency signal (1 Hz) is used as the measurement signal as shown in FIG. Even if there is an interference noise component due to the higher fluid modulation frequency (2 Hz) in addition to the original signal O1 (1 Hz) in the signal that has passed through the bandpass filter a1 in the system, synchronize that signal. If the synchronous rectification is performed by the detection rectifier b1, the noise component (2 Hz) is synchronously detected and rectified in such a manner that the smoothing value by the smoothing element c1 thereafter is offset by plus / minus and becomes zero. A correct measurement signal corresponding to only the original signal O1 (1 Hz) will be obtained from the element c1. On the contrary to the above, even in a system in which the higher frequency signal (2Hz) is used as the measurement signal, the interference noise component due to the lower frequency signal (1Hz) is similarly canceled by the plus / minus smoothed value. It will be easily understood from FIG. 7 (b) that the correct measurement signal having zero measurement value can be obtained.

7 (a) and 7 (b), the case where the original signal and the interference noise component whose frequencies are different from each other are in the same phase is illustrated.
As shown in (b), even if there is a phase shift θ between them, the interference noise component becomes 0 by the plus / minus offset of the smoothed value.

[Problems to be solved by the invention]

However, as described above, "both fluid modulation means V1, V
2 is set so that the ratio of the fluid modulation frequencies F1 and F2 due to them is an even number or a fraction of an even number, and "the other frequency (F2) in the system that uses one frequency signal F1 as the measurement signal" Although the purpose of "reducing measurement error due to interference noise component of" was achieved, it was found that the following problems still remained.

As described above, the actual modulation frequencies of the sample fluids S1 and S2 that are fluid-modulated by the respective fluid modulation means V1 and V2 are:
Whatever the structure of the fluid modulation means V1 and V2 is, it is caused by a deviation of mechanical duty due to manufacturing errors, driving unevenness of a driving mechanism, a flow path difference to the detection unit A, or the like. Inevitably, noise components having frequencies other than the original fluid modulation frequencies F1 and F2 are included. That is, in the fluid modulation frequency of the sample fluid S1 by the one fluid modulation means V1, in addition to the original fluid modulation frequency F1, the other system frequency F2 and other harmonic noise components are included, and Sample fluid S2 by the other fluid modulation means V2
In addition to the original fluid modulation frequency F2, the fluid modulation frequency of 1 includes the other system frequency F1 and other harmonic noise components.

Regarding the harmonic noise component among these noise components, the bandpass filter a1 in the signal processing unit B is used.
(A2) and the smoothing element c1 (c2) are effectively worked and removed, but the other fluid modulation means generated from the fluid modulation means V1 (V2) in the system of one fluid modulation frequency F1 (F2) A noise component having the same frequency as the fluid modulation frequency F2 (F1) of V1 (V2) is, for example, one fluid modulation frequency F1.
Is 1 Hz and the other fluid modulation frequency F2 is 2 Hz. As is clear from FIGS. 9 (a) and 9 (b), the noise component signal is mainly due to mechanical factors. Since there is usually a phase shift θ (the value of which is unknown) from the original signal, the synchronous detection rectifier b
It is not effectively removed even by the synchronous detection action of 1 and b2, so that the smoothed value does not become 0 but remains as a measurement error.

The present invention has been made in view of such circumstances,
Its purpose is to easily and easily eliminate the measurement error caused by the above-mentioned cause, that is, "the measurement error caused by the interference noise component of the same frequency signal from the other system in the system using one frequency signal as the measurement signal". Another object of the present invention is to provide a fluid analysis device by a multi-fluid modulation system having a mechanism capable of surely correcting.

[Means for solving problems]

In order to achieve the above-mentioned object, the device of the present invention is a fluid analysis device by the multi-fluid modulation method having the improved basic structure as described above, that is, two sample fluids (also divided into two systems). To
Fluid analysis means for performing fluid modulation at frequencies different from each other by a comparison fluid; and an analysis unit having only one detector, and each of the fluid-modulated sample fluids being supplied simultaneously and continuously, In order to obtain an analysis value for each sample fluid by separating the output signal from the detector in the analysis unit into signal components of each modulation frequency for each sample fluid and performing rectification and smoothing respectively. From the output signal from the detector, two bandpass filters that pass only the signals in the bands near the respective modulation frequencies are provided in parallel with each other, and the bandpass filters corresponding to the passband frequencies are provided after the bandpass filters. The output signal from the bandpass filter is detected and adjusted in synchronization with the actual fluid modulation operation by the fluid modulation means. Provided synchronous detection rectifier that, and the subsequent stage of the synchronous detection rectifier,
In a fluid analysis apparatus by a multi-fluid modulation method, which comprises a signal analysis means provided with a smoothing element for smoothing an output signal therefrom, the both fluid modulation means are respectively provided with an inlet of a sample fluid,
A rotary valve is provided which is provided with a flow path switching rotor that can be rotationally driven at a predetermined cycle in a housing provided with a comparative fluid inlet, an outlet to the analysis unit, and an outlet, and both rotary valves are provided. , And set them so that the ratio of the fluid modulation frequencies is even or even divided by 1,
In addition, the housing is configured to be rotatable and fixed around the rotation axis of the rotor so that the initial relative positional relationship between the housing and the rotor in at least one of the rotary valves can be arbitrarily adjusted and set. There is a feature in that there is.

[Action]

The action exerted by the above characteristic configuration is as follows.

That is, the above-mentioned device of the present invention basically has the same configuration as the fluid analysis device by the multi-fluid modulation method according to the improved prior art constructed by the combination of the above-mentioned FIG. 6 and FIG. Therefore, it is possible to reduce the "measurement error caused by the interference noise component of the other frequency signal in the system using one frequency signal as the measurement signal" as much as possible. Of course, both fluid modulation means can be rotationally driven at a predetermined cycle in a housing provided with a sample fluid inflow port, a comparison fluid inflow port, an outflow port to the analysis section, and an exhaust port, respectively, for flow path switching rotor. And a rotary valve having at least one of the rotary valves in at least one of the rotary valves. Is configured to be rotatable and fixed around the rotation axis of the rotor, the relative position of the fluid modulation operation by the rotary valves can be adjusted by arbitrarily adjusting and setting the initial relative positional relationship between the housing and the rotor. The relationship is arbitrarily adjusted, specifically, for example, in the state where the span fluid is flowed as the sample fluid only in one measurement system, the measurement value in the other system is
Even if a measurement error occurs due to an unknown phase shift as shown in the lower graph of FIG. 9 (a) or (b), while looking at the indicator, the measurement error will be almost zero. By simply rotating the housing of the rotary valve in the one system and adjusting the initial relative positional relationship between the housing and the corresponding rotor, it is possible to "reduce one frequency signal as a measurement signal". The measurement error caused by the interference noise component of the same frequency signal from the other system in the one system can be reliably corrected.

That is, by performing such adjustment operation, the interference noise component of the same frequency signal has a phase shift of 90 ° from an arbitrary value θ with respect to the original signal, as shown in FIG. 1 (a) or (b). It is corrected to be (π / 4), and as a result, the smoothed value becomes 0 as a result of synchronous detection and rectification as shown in the figure.

〔Example〕

Hereinafter, a specific embodiment of the fluid analysis device by the multi-fluid modulation method according to the present invention will be described with reference to the drawings (FIG. 2).

The device of the present invention is constructed by the combination of the above-mentioned FIG. 6 and FIG. 4, that is, both fluid modulation means V1, V2.
Are set so that the ratio of the fluid modulation frequencies F1 and F2 due to them is even or even divided by 1 (F1 = lHz, F2 = 2hlH
z or vice versa: h is an integer), which is a basic configuration of an improved prior art fluid analysis device using a multi-fluid modulation method (details thereof have already been described, and are omitted here). To).

Thus, in the present embodiment, the second embodiment of the fluid analysis device based on the multi-fluid modulation method having the above-mentioned basic configuration is provided.
As is clear from the schematic configuration diagram of FIG. 2A and the specific schematic configuration diagram of FIG. 2B, the fluid modulation means V1.
(V2) is a housing provided with an inflow port 3 for the sample fluid S1 (S2), an inflow port 5 for the comparative fluid R1 (R2), an outflow port 6 to the analysis unit A, and an exhaust port 4 to the exhaust flow path. A rotary valve is provided in which a flow path switching rotor R that can be rotationally driven in a predetermined cycle by a drive mechanism described later is provided in H.

As described above, both rotary valves are set so that the ratio of the fluid modulation frequencies F1 and F2 by them is even or even 1 / (for example, F1 = 1 Hz, F2 =
2Hz).

Then, as will be described later in detail, at least one (V1 in this example) of the both fluid modulating means (rotary valves) V1 and V2 has an initial relative positional relationship between the housing H and the rotor R arbitrarily. The position of the housing H can be changed and fixed so that it can be adjusted and set, that is, the housing H can be rotated and fixed around the rotation axis Y of the corresponding rotor R as indicated by a white arrow X in the drawing. There is.

That is, one of the two fluid modulation means (rotary valve)
The housing H of V1 is mounted on the base 10 so as to be slidably rotatable in a free state, and from above, the pressing plate 11 fixed to the base 10 by bolts 12 ...
Thus, it is configured so as to be pressed and fixed in an arbitrary rotation posture. Therefore, if the bolts 12 are loosened or the pressing plate 11 is removed together, and the housing H is freed, the rotational position of the housing H can be adjusted easily and arbitrarily. On the other hand, the housing H of the other two fluid modulation means (rotary valve) V2 is configured to be fixed directly on the base 10 in a fixed posture by bolts 13 ...

By the way, the drive mechanism for the rotors R, R of both rotary valves is as follows.

That is, in this example, the higher fluid modulation frequency (2H
The rotor R of the rotary valve constituting the fluid modulation means V2 having z) is set to the motor 7 whose rotation speed is controlled to 2 Hz.
While it is driven to rotate directly by, the lower fluid modulation frequency (1H
The rotor R of the rotary valve constituting the fluid modulation means V1 having z) is rotationally driven by the reduction gear mechanism 8 that reduces the rotation speed of the motor 7 to half. The rotary shaft system from the motor 7 to the corresponding rotor R and the rotary shaft system from the reduction gear mechanism 8 to the corresponding rotor R are respectively
For example, an optical type (photointerrupter or the like) for generating and supplying a frequency signal representing an actual modulation operation by each of the fluid modulation means V1 and V2 to the synchronous detection rectifiers b1 and b2 in the signal processing unit B. Sync signal generators 9a, 9
b is provided.

Now, in the fluid analysis device by the multi-fluid modulation method configured as described above, the span fluid is flowed as the sample fluid only to the measurement system of one fluid modulation means V1 (rotary valve) that is adjustable as described above. In this state, the housing H of the rotary valve is rotated by trial and error while observing the indicator, and the initial position is adjusted and set so that the measured value in the other system becomes 0. As described in detail in the above section [Operation], it is only necessary to perform an extremely easy operation of adjusting the initial relative positional relationship between the housing H and the rotor R.
Not only can “a measurement error caused by an interference noise component of the other frequency signal in the system that uses one frequency signal as the measurement signal” reduced as much as possible, but also “a system that uses one frequency signal as the measurement signal. The measurement error due to the interference noise component of the same frequency signal from the other system can be reliably corrected.

In the above embodiment, one of the fluid modulation means V1
Although only the rotary valve constituting the housing H has the housing H rotatable / fixable with respect to the rotor R, the rotary valve constituting the other fluid modulating means V1 may have such a structure. Also,
Even if it does so about both rotary valves which comprise both fluid modulation means V1 and V2, it does not interfere.

Further, in the above-described embodiment, the configuration is such that both rotary R, R of both fluid modulating means (rotary valves) V1, V2 are driven by one motor 7 by using the reduction gear mechanism 8. However, both rotors R, R may be separately driven by separate motors having different rotational speeds.

〔The invention's effect〕

As is clear from the above detailed description, according to the fluid analysis device by the multi-fluid modulation method according to the present invention, both fluid modulation means are provided in the fluid analysis device by the multi-fluid modulation method according to the improved prior art described above. A rotary valve having a flow path switching rotor that can be rotationally driven at a predetermined cycle in a housing having a sample fluid inlet, a comparison fluid inlet, an outlet to the analysis unit, and an outlet. And rotating the housing around the rotation axis of the rotor so that the initial relative positional relationship between the housing and the rotor in at least one of the rotary valves can be adjusted and set arbitrarily.
Since it is configured to be fixable, the initial relative positional relationship between the housing and the rotor, and by extension, the relative phase relationship of the fluid modulation operation by the both rotary valves, can be adjusted very easily. Of course, the basic action of being able to reduce “a measurement error caused by an interference noise component or the like of the other frequency signal in the system in which one frequency signal is the measurement signal” is exhibited as much as possible.
It is possible to surely correct "a measurement error caused by an interference noise component of the same frequency signal from the other system in a system using one frequency signal as a measurement signal", and it is possible to obtain more excellent measurement accuracy. The remarkable effect that it is possible is exhibited.

[Brief description of drawings]

FIGS. 1 (a) and 1 (b) are explanatory views of the action of the fluid analysis device by the multi-fluid modulation method according to the present invention, respectively. 2 (A) and 2 (B) are schematic configuration diagrams of a main part and a specific configuration diagram (schematic side view) in an embodiment of the fluid analysis device by the multi-fluid modulation method according to the present invention.
Is shown. Further, FIGS. 3 to 9 are for explaining the technical background of the present invention and problems in the prior art, and FIGS. 3 and 4 show the multi-fluid modulation method according to the prior art. Basic concept of fluid analysis device, and
Explanatory drawing of the concrete structure of the main part, FIG. 5 (a), (b)
Shows an explanatory view of the problems, respectively, and FIG. 6 is an overall schematic configuration diagram of a fluid analysis device by a multi-fluid modulation system in which the problems are improved, FIGS. 7 (a), 7 (b) and 8
Figures (a) and (b) are explanatory diagrams of their effects, respectively, and
9 (a) and 9 (b) show explanatory views of other problems, respectively. S1, S2: sample fluid, R1, R2: comparative fluid, F1, F2: fluid modulation frequency, V1, V2: fluid modulation means, (rotary valve) H: housing, R: rotor, 3: sample fluid S1 (S2) Inlet, 4: outlet, 5: comparative fluid R1 (R2) inlet, 6: outlet to detector A, A: analyzer, D: detector, B: signal processing means, O: detection Output signal from the device D, O1, O2: Each modulation frequency F1, F2 for each sample fluid S1, S2
Signal components, a1, a2: bandpass filter, b1, b2: synchronous detection rectifier, c1, c2: lowpass filter.

Claims (1)

[Claims] 1. A fluid modulation means for fluid-modulating two (or shunted into two systems) sample fluids at different frequencies by a reference fluid, respectively, and a single detector, and An analysis section to which each fluid-modulated sample fluid is supplied simultaneously and continuously, and an output signal from the detector in the analysis section is separated into signal components of each modulation frequency for each sample fluid and rectified respectively. And a smoothing process, in order to obtain an analysis value for each of the sample fluids, two band-pass filters that pass only signals in the bands near each of the modulation frequencies from the output signal from the detector are mutually separated. The actual fluid modulation by the fluid modulation means corresponding to the pass band frequency is provided in parallel with the band pass filters provided in parallel. In synchronism with the work, synchronous detection rectifier for detecting rectifying the output signal from the band-pass filter provided, and the subsequent stage of the synchronous detection rectifier,
In a fluid analysis device by a multi-fluid modulation system, which comprises a smoothing element for smoothing an output signal therefrom, the both fluid modulating means are respectively provided with a sample fluid inlet port
A rotary valve is provided which is provided with a flow path switching rotor that can be rotationally driven at a predetermined cycle in a housing provided with a comparative fluid inlet, an outlet to the analysis unit, and an outlet, and both rotary valves are provided. , And set them so that the ratio of the fluid modulation frequencies is even or even divided by 1,
In addition, the housing is configured to be rotatable and fixed around the rotation axis of the rotor so that the initial relative positional relationship between the housing and the rotor in at least one of the rotary valves can be arbitrarily adjusted and set. A fluid analysis device using a multi-fluid modulation method characterized by the following.