JP2000206037A - Spectroscopic analytical method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spectroscopic analytical method in which the component of a sample can be analyzed with high accuracy by a method wherein an influence due to a change in the output characteristic of a light receiving element due to the passage of time is removed by using a specific procedure. SOLUTION: A linear image sensor 4 detects, by using a plurality of light receiving elements, the intensity of a luminous flux, at every wavelength, which is spectrally reflected by a concave diffraction grating 3, and it outputs a signal according to the intensity of the luminous flux at every wavelength. A control part 5 uses a microcomputer, it processes output information from the sensor 4, it obtains an absorbence spectrum and a quadratic differential value in the wavelength region of the absorbence spectrum, and it calculates the component amount of a sample by using a specific working expression on the basis of the quadratic differential value. In addition, the control part 5 controls a motor 12 for filter changeover, a motor 16 for incident-light changeover and a motor 26 for a shutter so as to be operated. It performs an operation to remove an influence due to a change in the output characteristic of the respective light receiving elements in the sensor 4 when the component of the sample is analyzed while light which is being received by the sensor 4 is being changed over variously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of irradiating a sample with a measuring light from a light source, spectrally detecting light, which is reflected light or transmitted light from the sample, and obtaining a spectral spectrum of the detected light. The present invention relates to a spectroscopic analysis method in which a plurality of light receiving elements arranged side by side receive light spectral spectra simultaneously for each wavelength, and analyze components contained in a sample based on light receiving information of the light receiving elements.

[0002]

2. Description of the Related Art When a sample is irradiated with light for measurement, it exhibits an absorption characteristic corresponding to the amount of the component contained in the sample in a wavelength range peculiar to the component. Alternatively, the detection light, which is transmitted light, is spectrally analyzed, and components contained in the sample are analyzed based on the spectrum. For example, in advance, in a sufficiently large population, based on the information of the absorbance at a wavelength specific to the component,
Arithmetic expressions (so-called calibration expressions) for analyzing the components are set, and the spectral spectrum of the light detected from the sample is received by a plurality of light receiving elements, and light receiving information at a wavelength specific to the components to be measured is obtained. Based on the above, the components are analyzed using the calibration formula. Conventionally, components have been analyzed using the received light information obtained by receiving the spectral spectrum of the detection light from the sample as it is.

[0003]

By the way, it has been found that the output characteristics of the light receiving element change due to various factors, and that the manner of changing the output characteristics differs for each light receiving element. For example, as shown in FIGS. 6 and 7, the output characteristic of the light receiving element changes according to the temperature of the measurement atmosphere and the amount of light incident on the light receiving element. It also changes over time.
FIG. 6 shows the output voltage when the measurement atmosphere temperature of each of the plurality of light receiving elements is 10 ° C. and 25 ° C. in the linear image sensor including the plurality of light receiving elements in a row.
FIG. 7 shows the relationship between the amount of incident light and the output of one specific light receiving element when the ambient temperature is T1 and T2.

Therefore, in the conventional method, since the received light information of the spectrum of the detected light is used as it is, the output characteristics of the light receiving element at the time of measurement are different from the output characteristics when the calibration equation is set. In that case,
There is a problem that the analysis accuracy of the components is deteriorated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a spectroscopic analysis method capable of accurately analyzing the components of a sample irrespective of a change in output characteristics of a light receiving element. It is in.

[0006]

According to the characteristic configuration of the present invention, a plurality of reference filters having different transmitted light amounts are prepared, and the light receiving elements are set in advance as reference reference information for each of the light receiving elements. The light receiving information of the spectral spectrum of the reference light having the measuring light from the light source transmitted through the reference filter is obtained, and the reference reference information is stored. At the time of measurement, for each light receiving element, light receiving information of the spectral spectrum of the reference light is obtained as measurement reference information for each reference filter. Then, based on the reference reference information for each reference filter, the measurement reference information for each reference filter, and the light reception information of the spectral spectrum of the light detected from the sample, the light reception from when the calibration equation is set for each light receiving element. The components of the sample are determined in consideration of the characteristic change of each element.

That is, in analyzing the components, it is possible to eliminate the influence of the change in the output characteristics of the light receiving element over time. Further, since the reference reference information and the measurement reference information are obtained by using a plurality of reference filters having different transmitted light amounts, even if the output characteristics change due to a difference in the temperature of the measurement atmosphere and the incident light amount to the light receiving element, the change is not obtained. The effect due to the change in the output characteristics can be eliminated. In addition, since the reference reference information and the measurement reference information are obtained for each light receiving element, it is possible to consider that the way of changing the output characteristics differs for each light receiving element. Therefore, the components of the sample can be analyzed with high accuracy regardless of the change in the output characteristics of the light receiving element.

According to a second aspect of the present invention, for each light receiving element, the light receiving information of the light receiving element is determined based on the reference reference information and the measurement reference information for each reference filter. A reference state conversion formula for converting into light reception information in the state is obtained. Then, using the reference state conversion formula, the received light information of the spectral spectrum of the light detected by the light receiving element is converted into the received light information in the reference state to obtain the reference state sample information, and the sample is obtained based on the reference state sample information. Find the components of For example, for each light receiving element, based on a plurality of pieces of reference reference information and measurement reference information, a reference state conversion equation, which is an equation indicating the correspondence between the reference reference information and the measurement reference information, is set. Then, using the reference state conversion formula, the light reception information of the light receiving element is converted into the light reception information in the reference state.

Incidentally, when the components of the sample are determined based on the reference reference information, the measurement reference information, and the received light information of the spectrum of the detected light in consideration of the characteristic change of each light receiving element, the following method is used. Conceivable. That is, using the reference reference information and the measurement reference information, a coefficient for correcting the provisional component value provisionally obtained based on the received light information of the spectral spectrum of the detected light to a value in consideration of the characteristic change is obtained. Then, a provisional component value is obtained based on the received light information of the spectral spectrum of the detection light,
It is conceivable that the provisional component value is corrected by the coefficient. Comparing the two methods, the method according to the second aspect can more effectively remove the influence of the change in the output characteristic due to the difference in the amount of incident light, and the component accompanying the change in the output characteristic. The error of the analysis value can be reduced. Therefore, it is possible to provide a preferable specific method for reducing an error of the component analysis value due to a change in the output characteristic of the light receiving element.

According to a third aspect of the present invention, in a light-shielding state in which light irradiation to a plurality of light-receiving elements is prohibited in a reference state, light-receiving information is obtained for each of the light-receiving elements and the light-receiving information is obtained in advance. It is stored as reference dark information. At the time of measurement, light receiving information is obtained as measurement dark information for each of the light receiving elements in the light-shielded state. Then, a reference state conversion formula is obtained based on the difference between the reference reference information and the reference dark information for each reference filter and the difference between the measurement reference information and the measured dark information for each reference filter. That is, in such a light receiving element, a current (a so-called dark current) flows even in the light-shielded state where no light is irradiated, and the dark current becomes noise when analyzing components. In addition, the dark current changes depending on the temperature of the measurement atmosphere and the elapsed time. For example, as shown in FIG. 7, the dark information D1 when the ambient temperature is T1, and the dark information D1 when the ambient temperature is T1.
2 is different from the dark information D2. Therefore, in the reference state, the dark information corresponding to the dark current is previously obtained and stored as the reference dark information, and at the time of measurement, the dark information is obtained as the measured dark information. Then, a change in the output characteristic is obtained by obtaining a reference state conversion formula based on the difference between the reference reference information and the reference dark information for each reference filter and the difference between the measurement reference information and the measurement dark information for each reference filter. It is possible to obtain a reference conversion formula that can remove the influence of the dark current in a state where the consideration is taken. Therefore, the components can be analyzed while removing the influence of the dark current in a state in which the change in the output characteristics of the light receiving element is taken into consideration, so that the component analysis accuracy can be further improved.

According to a fourth aspect of the present invention, light-receiving information of a spectral spectrum of detected light is obtained by a plurality of light-receiving elements in a state where the sample is not irradiated with measurement light, and the light-receiving information is obtained. The light is converted into light reception information in the reference state using the reference state conversion formula, and reference state disturbance light information is obtained.
Then, based on the reference state sample information and the reference state disturbance light information, the reference state disturbance light information is processed as information corresponding to disturbance light other than the detection light, and components contained in the sample are analyzed. That is, in a state where the sample is irradiated with the measurement light, the light received by the light receiving element includes the detection light from the sample and other light (hereinafter, sometimes referred to as disturbance light), When the sample is not irradiated with the measuring light,
Since the light received by the light receiving element is only disturbance light, the light receiving information of the light receiving element obtained without irradiating the sample with the measuring light is converted into the light receiving information in the reference state using the reference state conversion formula. Then, the reference state disturbance light information is obtained, and the reference state disturbance light information is processed as information based on the disturbance light, thereby removing the influence of the disturbance light in a component analysis in a state in which a change in the output characteristic is considered. You can do it. On the other hand, by providing a hood or the like for blocking disturbance light, it is conceivable to remove the influence of the disturbance light on the component analysis, but it is not only troublesome to attach and detach the hood, but in some cases, the hood is covered with the hood. It may not be possible to analyze the components in the state. For example, there is a case where a component of a growing fruit or vegetable is analyzed. Therefore, it is possible to remove the influence of the disturbance light in a state in which the change in the output characteristics is taken into consideration without providing a means for shielding the disturbance light such as a hood, thereby eliminating the operation for blocking the disturbance light. The component analysis accuracy can be further improved while simplifying the operation.

According to a fifth aspect of the present invention, there is provided a calibration filter capable of obtaining calibration light having at least two peak portions in a wavelength range for component analysis.
At the time of measurement, the spectral spectrum of the calibration light that has passed through the calibration filter is received by a plurality of light-receiving elements, and the received light information is converted into light-receiving information in the reference state using a reference state conversion formula, and the reference state is converted. In addition to obtaining the calibration information, the correspondence between the plurality of light receiving elements and the light receiving wavelength is obtained based on the reference state calibration information, and the light receiving wavelength of each light receiving element is calibrated based on the correspondence. In other words, the wavelength of the light received by each of the plurality of light receiving elements is determined by the positional relationship with the optical component that separates the detection light, and this positional relationship is small due to the influence of the temperature of the measurement atmosphere and the passage of time. The position may deviate from the positional relationship in the state. On the contrary,
While taking into account the change in the output characteristics of the light receiving element, adapted to the positional relationship between the light receiving element and the optical component at the time of measurement,
The correspondence between the plurality of light receiving elements and the light receiving wavelengths is obtained, and the light receiving wavelength of each light receiving element is calibrated based on the correspondence. Therefore, the correspondence between the plurality of light receiving elements and the light receiving wavelength is calibrated to an appropriate state adapted to the state at the time of measurement,
Since the components can be analyzed, the component analysis accuracy can be further improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a spectroscopic analyzer to which the spectroscopic analysis method of the present invention is applied will be described below with reference to the drawings. As shown in FIG.
Irradiating the sample S with the measuring light from the light source 1 and receiving the detection light which is the diffuse reflection light from the sample S; A concave diffraction grating 3, which splits the spectrum to obtain a spectrum of the detection light,
A linear image sensor 4 having a plurality of light receiving elements arranged in a row so as to simultaneously receive the spectral spectrum of the detection light obtained by the concave diffraction grating 3 for each wavelength, based on light receiving information of the linear image sensor 4 And a control unit 5 for analyzing components contained in the sample, a display unit 6 for displaying and outputting the analysis results by the control unit 5, and the like.

Further, in order to remove the influence of the change in the output characteristics of each light receiving element of the linear image sensor 4 on the component analysis, various kinds of measurement light from the light source 1 are used in addition to the detection light from the sample S. There is provided an incident light switching section M for variously switching the light to be incident on the concave diffraction grating 3 such that the light is incident on the concave diffraction grating 3 while passing through a filter.

The light source 1 is provided with a tungsten-halogen lamp which emits infrared light as measurement light.

Furthermore, the measuring light from the light source 1
, An optical fiber for detection 7 for guiding the light received by the light emitting and receiving unit 2 to the incident light switching unit M, and a calibration for directly guiding the measuring light from the light source 1 to the incident light switching unit M. Optical fiber 9 is provided.

Although the detailed description of the light emitting and receiving unit 2 is omitted,
It has a ring-shaped irradiation unit 2o and a circular light receiving unit 2i located concentrically inside the ring-shaped irradiation unit 2o, and measurement light guided by the irradiation optical fiber 7. Is irradiated from the irradiating section 2o, and the light received by the light receiving section 2i is guided so as to be incident on the optical fiber 8 for detection. Then, the distance between the irradiation unit 2o and the light receiving unit 2i is set to about 20 mm,
The diffusely reflected light reflected inside the sample S can be received by the light receiving section 2i.

The concave diffraction grating 3 is arranged at a position where the light incident from the slit 10s can be spectrally reflected in the dark box 10 for a spectroscopic section having the slit 10s into which the light to be spectrally incident. The linear image sensor 4 is
In the spectroscopic unit dark box 10, the spectroscopic spectrum reflected by the concave diffraction grating 3 is arranged so as to be simultaneously received by a plurality of light receiving elements. Then, the linear image sensor 4 detects the light flux intensity for each wavelength spectrally reflected by the concave diffraction grating 3 by a plurality of light receiving elements, and outputs a signal corresponding to the light flux intensity for each wavelength. It is configured in.

The incident light switching section M will be described. A filter-equipped disk 11 provided rotatably around an axis parallel to the incident optical path P in a state orthogonal to the incident optical path P with respect to the slit 10s, and a filter switching mechanism for driving the filter-equipped disk 11 to rotate. It has a motor 12, an optical fiber 13 for detecting light guiding and an optical fiber 14 for calibrating light guiding, and the light emitting end face of each of the optical fibers 13, 14 is located on the upstream side of the incident optical path P with respect to the filter mounting disk 11. A fiber support 15 provided to be reciprocally linearly movable so as to be alternately positioned on the incident optical path P, and an incident light switching motor 16 for moving and driving the fiber support 15
And the fiber support 1 by the incident light switching motor 16.
5 is provided with a gear mechanism 17 for connecting them so as to drive the reciprocating linear movement. The filter-equipped disk 11, the filter switching motor 12, the fiber support 15, the incident light switching motor 16, and the gear mechanism 17 are provided with an incident light switching unit dark box 18 for preventing harmful light from entering the incident optical path P. It is provided inside.

As shown in FIG. 2, three reference filters 19 having different amounts of transmitted light are arranged on the filter-equipped disk 11 in a state of being arranged along the circumference intersecting the incident optical path P.
a, 19b, 19c, a calibration filter 20 for obtaining calibration light having at least two peaks in a wavelength range for component analysis, a light-shielding portion 21 that does not allow light to pass, and an opening 22.

Further, as shown in FIG. 4A, when the fiber support 15 is moved so that the exit end face of the detection light guiding optical fiber 13 is located on the incident optical path P,
The detection optical fiber 8 is connected to the incident light switching section dark box 18 so that the exit end face of the detection optical fiber 8 faces the light incident end face of the detection light guiding optical fiber 13.
Hereinafter, as described above, the emission end face of the detection light guiding optical fiber 13 is located on the incident optical path P, and the incidence end face of the detection light guiding optical fiber 13 and the emission end face of the detection optical fiber 8 face each other. The state in which the light guided by the detection optical fiber 8 enters the incident optical path P may be referred to as a detection light incidence state.

As shown in FIG. 4B, when the fiber support 15 is moved so that the exit end face of the calibration light guiding optical fiber 14 is positioned on the incident optical path P,
The calibration optical fiber 9 is connected to the incident light switching section dark box 18 such that the emission end face of the calibration optical fiber 9 faces the incidence end face of the calibration light guide optical fiber 14. Hereinafter, as described above, the emission end face of the calibration light guide optical fiber 14 is located on the incident optical path P, and the incidence end face of the calibration light guide optical fiber 14 and the emission end face of the calibration optical fiber 9 face each other. The state where the light guided by the calibration optical fiber 9 enters the incident optical path P may be referred to as a calibration light incident state.

As shown in FIG. 3, the light source 1 irradiates the shutter disk 23 provided with the light-passing openings 23w and the light-shielding portions 23c that block the light alternately in the circumferential direction. A shutter motor 24 for rotatably driving the shutter disk 23 is provided so as to be rotatable in a state of crossing the incident optical path with respect to the incident end face of the optical fiber 7. Then, the shutter disk 23 is driven by the shutter motor 24.
Is rotated at a constant speed, so that the sample S is periodically switched between an irradiation state in which the sample light is irradiated and a non-irradiation state in which the measurement light is not irradiated.

Next, the control operation of the control unit 5 for analyzing the components will be described. The control unit 5 is configured using a microcomputer, and basically processes output information from the linear image sensor 4 to obtain an absorbance spectrum and a second derivative value in a wavelength region of the absorbance spectrum. Is obtained, and the component amount Q is calculated based on the secondary differential value based on the calibration equation of the following equation 1.

[0025]

(Equation 1) Q = K ₀ + K ₁ × A (λ ₁ ) + K ₂ × A (λ ₂ ) + K ₃
× A (λ ₃ ) ……

Where K ₀ , K ₁ , K ₂ , K ₃ ...; Coefficients A (λ ₁ ), A (λ ₂ ), A (λ ₃ ) obtained from a sufficiently large population; λ
Derivative of absorbance spectrum at

The control unit 5 includes a filter switching motor 1.
2. Incident light switching motor 16 and shutter motor 24
In analyzing the components while controlling the respective operations to variously change the light received by the linear image sensor 4, a process for removing the influence due to the change in the output characteristics of each light receiving element of the linear image sensor 4 is performed. Do. Less than,
The processing will be described.

In advance, when the measuring atmosphere temperature is a reference temperature (for example, 25 ° C.) and the calibration light is incident by the operation of the incident light switching motor 16, the filter switching motor 12 causes the reference filter 19a,
19b and 19c are sequentially positioned on the incident optical path P, and for each reference filter, for each light receiving element, output information of the spectral spectrum of the reference light in which the measuring light from the light source 1 has passed through the reference filter is used as reference reference information Ra _{e. (i), Rb e (i} ), together with obtained as Rc _e (i), allowed to store the reference reference information in the storage section 5m of the control unit 5. However, i = 1, 2, 3 ...
, And are the numbers of the light receiving elements.

At the reference temperature, the light-shielding portion 21 is positioned on the incident optical path P by the filter switching motor 12 so that the light irradiation to the linear image sensor 4 is prohibited. The information is obtained and the received light information is stored in the storage unit 5m as the reference dark information _De (i).

At the time of measurement, the incident light switching motor 16
In the state where the calibration light is incident by the operation of the above, the reference filter 19 is driven by the filter switching motor 12.
a, 19b, 19c sequentially is located in the incident light path P and for each reference filter, the light receiving element respectively measuring the reference information received information spectrum of the reference light _{Ra m (i), Rb m} (i), Rc _m (i). Further, the light-shielding portion 21 is positioned on the incident optical path P by the filter switching motor 12, and in the light-shielding state, light-receiving information is obtained for each of the light-receiving elements, and the light-receiving information is obtained as measurement dark information D _m (i). .

In the state where the calibration light is incident by the operation of the incident light switching motor 16, the calibration filter 20 is positioned on the incident optical path P by the filter switching motor 12, and the linear image sensor 4 As a state in which the measuring light from the light source 1 receives the spectrum of the calibration light that has passed through the calibration filter 20, measurement calibration information V _m (i) is obtained for each of the light receiving elements.

In the state where the detection light is incident by the operation of the incident light switching motor 16, the shutter motor 2
4 is operated for a set time so that the irradiation state and the non-irradiation state can be periodically switched. Then, for each of the light receiving elements, measured disturbance light-containing sample information Sw _m (i) as information in the irradiation state, and
As the information in the non-irradiation state, measured disturbance light information Sc _m
(I) is obtained.

Subsequently, a reference state conversion formula setting process is performed as follows. That is, for each light receiving element, the storage unit 5
m, reference reference information Ra stored in
_{e (i), Rb e (} i), Rc e (i) and reference dark information D _e (i), as well as the measurement reference information R measured
_{a m (i), Rb m} (i), Rc m (i) and the measured dark information D _m a (i), was processed as shown in Equation 2 below, using these processing results, the least squares After approximation, as shown in FIG. 5, coefficients α (i), β
Find (i).

[0034]

[Number 2] (Equation 2) Xa (i) = Ra m (i) -D m (i) Xb (i) = Rb m (i) -D m (i) Xc (i) = Rc m (i) _{-D m (i) Ya (i} ) = Ra e (i) -D e (i) Yb (i) = Rb e (i) -D e (i) Yc (i) = Rc e (i) -D _e (i) (Equation 3) Y = α (i) × X + β (i)

However, when the information stored in the storage unit 5m is obtained (hereinafter sometimes referred to as a reference state), the output information of the light receiving element is E (i), and the output information of the light receiving element at the time of measurement is M ( Assuming that i), X and Y are represented by Equation 4 below.

[0036]

X = M (i) −D _m (i) Y = E (i) −D _e (i)

Subsequently, the control unit 5 performs a reference state conversion process of converting the received light information obtained at the time of measurement into a value in the reference state. In other words, the measured disturbance light-containing sample information Sw _m (i) is converted into a value in the reference state using the above Expressions 3 and 4, and the reference state disturbance light-containing sample information Sw _e (i) is obtained. That is, the measurement disturbance light-containing sample information Sw _m (i)
Let M (i) be the output information of the light receiving element at the time of measurement,
Output information E of the light receiving element in the reference state (i) is determine as a reference state disturbance light containing sample information Sw _e (i). Similarly, using the above equations 3 and 4, the measured disturbance light information Sc _m (i) is converted into a value in the reference state to obtain the reference state disturbance light information Sc _e (i), and the measurement calibration is performed. The information V _m (i) is converted into a value in the reference state to obtain reference state calibration information V _e (i).

Subsequently, disturbance light information removal processing is performed as follows. That is, based on the following equation 5, the reference state disturbance light-containing sample information Sw _e (i) and the reference state disturbance light information S
The c _e (i), and the reference state ambient light information Sc _e (i) is treated as information only by disturbance light, as the information of the detection light by only measurement light from the light source 1, the reference state ambient light-free sample Obtain information S (i).

[0039]

[Number 4] (Equation 5) S (i) = Sw e (i) -Sc e (i)

Subsequently, a wavelength calibration process is performed as follows. That is, using the reference state calibration information V _e (i), the correspondence between the plurality of light receiving elements and the light receiving wavelength is obtained, and the light receiving wavelength of each light receiving element is calibrated.

Then, in the state where the light receiving wavelength of each light receiving element is calibrated as described above, based on the calibration equation shown in the above equation 1, using the reference state disturbance light free sample information S (i). , The component amount Q is calculated.

[Another Embodiment] Next, another embodiment will be described. (A) When the dark current of the light receiving element of the linear image sensor 4 is small and its influence on the component analysis can be neglected, in the above embodiment, the light shielding unit 21 is positioned on the incident optical path P and the light shielding is performed. As the state, the reference dark information _De
The process of obtaining (i) and storing it in the storage unit 5m and the process of obtaining the measurement dark information D _m (i) as the light-shielding state at the time of measurement are also omitted, and the reference state conversion is performed. In the equation setting process, the reference information Ra _{e
(I), Rb e (i} ), Rc e (i) and measuring the reference information _{Ra m (i), Rb m} (i), only Rc _m (i), the coefficient giving the equation 3 above alpha (i) , Β (i). Therefore, the light shielding part 21 can be omitted. Therefore, in the reference state conversion processing, the expression 3
Is used to determine the measured disturbance light-containing sample information Sw _m (i) as X, and Y as the reference state disturbance light-containing sample information Sw _e (i). Similarly, the measured disturbance light information Sc _m (i) is calculated as X , Y is obtained as reference state disturbance light information Sc _e (i), measurement calibration information V _m (i) is set as X, and Y is obtained as reference state calibration information V _e (i). In this case, the time required for the analysis can be reduced, and the configuration of the apparatus can be simplified.

(B) In the case where a hood or the like that blocks disturbance light is provided and analysis is performed in a state where disturbance light is not incident, detection light can be obtained in a state where disturbance light is not included. In the above, the process for obtaining the measured disturbance light information Sc _m (i) and the process of removing the disturbance light information are not required. Therefore, the shutter disk 23 and the shutter motor 24 can be omitted. In this case, the time required for the analysis can be reduced, and the configuration of the apparatus can be simplified.

(C) If there is no or small change in the positional relationship between the plurality of light receiving elements and the optical components that disperse the detection light from the sample, and the influence of the change on the component analysis can be ignored. In the embodiment, the calibration filter 20 is used.
Is located in the incident optical path P, the measurement calibration information V _m (i) is obtained, and the wavelength calibration processing for obtaining the correspondence between the plurality of light receiving elements and the received light wavelengths can be omitted. Therefore, the calibration filter 20 can be omitted. In this case, the time required for the analysis can be reduced, and the configuration of the apparatus can be simplified.

(D) Another embodiment of omitting the process for removing the influence of the dark current of the light receiving element as described in (a) above, and removing the disturbance light information as described in (b) above In another embodiment in which the processing is omitted, and in another embodiment in which the wavelength calibration processing is omitted as described in (c) above, all of them may be executed, or any two of them may be executed. May be performed, or one of them may be omitted.

(E) In the above-described embodiment, in the reference state conversion processing, the measured disturbance light-containing sample information Sw _m (i) is set to X using Expression 3, and Y is set to the reference state disturbance light-containing sample information Sw _e. (I), and similarly, the measured disturbance light information Sc _m (i) is X, and Y is the reference state disturbance light information S
It may be obtained as c _e (i), the measurement calibration information V _m (i) as X, and Y as reference state calibration information V _e (i). In this case, the error of the component analysis is slightly increased, but the arithmetic processing can be simplified.

(F) The number of reference filters having different amounts of transmitted light is not limited to the three illustrated in the above embodiment, but may be two.
Four or more may be used. As the number of installations increases, the analysis accuracy can be improved, but the processing time becomes longer.

(G) In the above embodiment, the case where diffuse reflected light is obtained as the detection light from the sample has been described. However, the detection light may be light reflected or transmitted from the sample. As means for irradiating the sample with measurement light and receiving the detection light from the sample, instead of the light emitting and receiving unit 2 exemplified in the above embodiment, according to the received detection light Various configurations are possible.

(H) The specific configuration of the incident light switching section M is not limited to the configuration exemplified in the above embodiment. For example, as a configuration for allowing the measurement light from the light source 1 to pass through the reference filter and the calibration filter 20, the measurement light emitted from the light emitting and receiving unit 2 is interposed between the light emitting and receiving unit 2 and the sample S. A reflecting mirror for reflection may be provided so as to be able to move back and forth, and the measuring light may be reflected by the reflecting mirror, received by the light emitting / receiving unit 2, and guided by the detection optical fiber 8. In this case, the calibration optical fiber 9, the fiber support 15, and the incident light switching motor 16 can be omitted. (I) In addition to the detection light from the sample S, the light to be incident on the concave diffraction grating 3 is variously switched such that the measurement light from the light source 1 is incident on the concave diffraction grating 3 while passing through various filters. In the above embodiment, the operation has been described by way of example in which the incident light switching unit M is provided and the operation is automatically performed. However, the operation may be performed manually.

The specific configuration of the light receiving device having a plurality of light receiving elements is not limited to the linear image sensor 4 exemplified in the above embodiment, and various devices such as a CCD may be used. Can be.

(G) In the method according to the present invention, samples to be analyzed for components include fruits and vegetables, grains, etc.
Various things can be applied. In addition, as components to be analyzed, various components such as sugar content and acid content can be analyzed according to the sample to be analyzed. Therefore, a calibration formula is set according to the sample and the component to be analyzed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a spectroscopic analyzer.

FIG. 2 is a diagram showing a disc for a filter device of the spectroscopic analyzer.

FIG. 3 is a diagram illustrating a shutter disk of the spectroscopic analyzer.

FIG. 4 is a diagram illustrating a configuration for switching light to be received by a light receiving element.

FIG. 5 is a diagram showing a reference state conversion formula.

FIG. 6 is a diagram showing a change in output characteristics of a light receiving element.

FIG. 7 is a diagram showing a change in output characteristics of a light receiving element.

[Explanation of symbols]

 Reference Signs List 1 light source 19a, 19b, 19c reference filter 20 calibration filter

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Ryoji Suzuki 1-1-1, Hama, Amagasaki-shi, Hyogo Prefecture Inside Kubota Technology Development Laboratory Co., Ltd. (72) Inventor Masayuki Kasu 1-1-1, Hama, Amagasaki-shi, Hyogo Stock (72) Inventor Ryogo Yamauchi 1-1-1 Hama, Amagasaki-shi, Hyogo F-term in Kubota Technology Development Laboratory Co., Ltd. (reference) 2G059 AA01 BB11 CC20 EE01 EE02 FF06 GG10 HH01 JJ02 JJ05 JJ17 JJ23 JJ30 KK04 LL04 MM01 MM05 MM10 MM14 NN05 NN06 PP04

Claims (5)

[Claims] A sample is irradiated with measurement light from a light source, and detection light, which is reflected light or transmitted light from the sample, is separated to obtain a spectrum of the detection light. A spectral analysis method in which a plurality of juxtaposed light receiving elements simultaneously receive light for each wavelength and analyze components contained in a sample based on light receiving information of the light receiving elements. Prepare and obtain, as reference reference information, in advance, for each of the light receiving elements, light receiving information of a spectral spectrum of reference light transmitted from the light source through the reference filter for measurement light from the light source for each of the reference filters. Reference information is stored, and at the time of measurement, for each of the light receiving elements, the reference information is stored for each of the reference filters. Obtaining light reception information of a spectral spectrum of reference light as measurement reference information, for each of the light receiving elements, the reference reference information for each of the reference filters, the measurement reference information for each of the reference filters, and detection light from a sample. Spectroscopic analysis method for determining the components of a sample based on the received light information of the spectrum. 2. For each of the light receiving elements, based on the reference reference information and the measurement reference information for each of the reference filters, the light receiving information of the light receiving element is changed to the light receiving information in a reference state in which the reference reference information is obtained. The reference state conversion formula is obtained by converting the received light information of the spectral spectrum of the detection light in the light receiving element into the received light information in the reference state using the reference state conversion formula. 2. The spectroscopic analysis method according to claim 1, wherein the components of the sample are obtained based on the obtained reference state sample information. 3. In a light-shielding state in which irradiation of light to the plurality of light-receiving elements is prohibited in the reference state, light-receiving information is obtained for each of the light-receiving elements, and the light-receiving information is stored as reference dark information. In the measurement, the light receiving information is obtained as measurement dark information for each of the light receiving elements in the light-shielded state, and the reference state conversion formula is obtained by calculating the reference state conversion formula using the reference reference information and the reference dark information for each reference filter. And the difference
3. The spectroscopic analysis method according to claim 2, wherein the determination is performed based on a difference between the measurement reference information and the measurement dark information for each of the reference filters. 4. During measurement, the plurality of light-receiving elements obtain light-receiving information of a spectral spectrum of detection light from the sample and do not transmit the light-receiving information while the sample is not irradiated with the measuring light. By converting the received light information in the reference state using the reference state conversion formula, to obtain the reference state disturbance light information, based on the reference state sample information and the reference state disturbance light information, the reference state disturbance light 4. The spectroscopic analysis method according to claim 2, wherein the information is processed as information corresponding to disturbance light other than the detection light, and a component contained in the sample is analyzed. 5. A calibration filter that can obtain calibration light having at least two peaks in a wavelength range for component analysis, and for measurement, disperse the calibration light transmitted through the calibration filter. The spectrum is received by the plurality of light receiving elements, the received light information is converted into the received light information in the reference state using the reference state conversion formula, and the reference state calibration information is obtained, and based on the reference state calibration information. 5. The spectral analysis method according to claim 2, wherein a correspondence between the plurality of light receiving elements and the light receiving wavelength is obtained, and the light receiving wavelength of each light receiving element is calibrated based on the correspondence. .