CN113218892A

CN113218892A - Measuring apparatus and measuring method

Info

Publication number: CN113218892A
Application number: CN202110133455.0A
Authority: CN
Inventors: 松仪泰明; 五所尾康博; 高桥秀和; 立石幸一
Original assignee: Azbil Corp
Current assignee: Azbil Corp
Priority date: 2020-02-05
Filing date: 2021-02-01
Publication date: 2021-08-06
Also published as: JP2021124387A

Abstract

The invention provides a measuring apparatus and a measuring method, which can measure the concentration of a measuring object such as solute dissolved in various solutions such as aqueous solution or various gases in mixed gas with high precision by a simple structure. The measurement system (1) of the present application includes: a light source device (2) which emits light including a specific wavelength corresponding to a measurement object of density by intermittently lighting the light emitting element; a tunable filter (4) for Fabry-Perot spectroscopy for at least splitting light having a wavelength different from a wavelength at which the light is split, from among the light received via the measurement object; light receiving elements (5) that measure the intensity of light split by the Fabry-Perot splitting tunable filter (4); and a measurement device (6) that generates a spectrum indicating the relationship between the wavelength of the light split by the tunable Fabry-Perot splitting filter (4) and the intensity of the light of each wavelength measured by the light receiving element (5).

Description

Measuring apparatus and measuring method

Technical Field

The present invention relates to a measuring apparatus and a measuring method for measuring spectra of a solution and a gas.

Background

Conventionally, a technique for measuring the concentration of an aqueous solution such as an etching solution or a cleaning solution for a semiconductor using light has been known. As an example of such a technique, a technique is known in which light emitted from a tungsten lamp is irradiated into an aqueous solution, and the concentration of the aqueous solution is measured from the intensity of light received via the aqueous solution. Further, there is known a technique in which light having a wavelength absorbed by a solute is emitted from a light source, and is dispersed using a diffraction grating or a color filter before or after passing through an aqueous solution, and the concentration of the aqueous solution is measured based on the absorbance of the dispersed light.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. Hei 11-037936

Patent document 2: japanese patent application No. 2019-

Disclosure of Invention

Problems to be solved by the invention

Here, in the above-described conventional techniques, it cannot be said that the concentration of the aqueous solution can be measured with high accuracy with a simple configuration.

For example, when the absorbance of an aqueous solution is measured using light emitted from a light emitting diode, the concentration of the aqueous solution cannot be measured with high accuracy using light having a wide wavelength. In addition, when light is dispersed using a diffraction grating or a color filter, an optical system becomes complicated. In view of such problems, the applicant has conceived the following measurement method: the light emitted from the led (light Emitting diode) is received through the object to be measured for density, the light having a specific wavelength corresponding to the object to be measured is dispersed from the received light, and the density of the object to be measured is measured based on the intensity of the dispersed light.

Here, when the measurement object is switched or when the concentration change is large, a method may be considered in which the spectrum of the light received via the aqueous solution is acquired, and a wavelength suitable for the concentration measurement is selected as the specific wavelength from the acquired spectrum. However, in the above-described conventional technique, since the amount of transmitted light is detected regardless of the wavelength, a change in spectrum cannot be obtained.

When an LED is used as the light source, the LED is pulsed on, thereby prolonging the life of the light source. However, in order to obtain the spectrum of the received light, it is necessary to change the wavelength of the light to be spectrally separated with time. Therefore, when the light emission time of the light source is shortened, the number of wavelengths of light that can be dispersed in 1 lighting is reduced, but when the lighting time per 1 frequency is short, the measurement accuracy is deteriorated.

In addition, with the same configuration as the above-described conventional technique, a method of measuring the concentration of each gas in a solution or a mixed gas in which various solutes are dissolved, in addition to the concentration of an aqueous solution, can be considered. However, in the above-described conventional techniques, it cannot be said that the concentrations of solutes and gases in various solutions can be measured with high accuracy with a simple configuration.

The present invention has been made to solve the above problems, and an object of the present invention is to accurately measure the concentration of a solute dissolved in various solutions such as an aqueous solution or the concentration of various gases in a mixed gas with a simple configuration.

Means for solving the problems

The measurement device of the present application includes: a light source unit that emits light including a specific wavelength corresponding to a measurement target of density by intermittently lighting a light emitting element; a spectroscopic unit that disperses at least light having a wavelength different from a wavelength of the dispersed light from the light received through the measurement object; a measurement unit for measuring the intensity of the light split by the splitting unit; and a generation unit that generates a spectrum indicating a relationship between the wavelength of the light split by the splitting unit and the intensity of the light of each wavelength measured by the measurement unit.

In the above measurement device, the spectroscopic unit may be a fabry-perot type spectroscopic unit.

In the above-described measurement device, the spectroscopic unit may be configured to disperse light having a predetermined number of wavelengths each time the light emitting element is turned on.

In the above-described measurement device, the spectroscopic unit may further diffract the light having the re-measured wavelength by using any one of the wavelengths dispersed when the light-emitting element was previously turned on as the re-measured wavelength, and the generation unit may generate the spectrum in which the intensities of the lights having the respective wavelengths are corrected based on the difference in the intensities of the lights having the re-measured wavelengths.

In the above-described measurement device, the spectroscopic unit may be configured to, every time the light emitting element is turned on, spectrally disperse light of a plurality of wavelengths including a predetermined re-measurement wavelength, and the generation unit may be configured to generate a spectrum in which the intensity of light of each wavelength is corrected based on a difference in intensity of light of the re-measurement wavelength.

In the above-described measurement device, the generation unit may determine whether or not the intensity of the light of each of the re-measurement wavelengths is an abnormal value based on a difference between the intensities of the light of the re-measurement wavelengths, and when it is determined that the intensity of any one of the light of the re-measurement wavelengths is an abnormal value, the generation unit may exclude the intensity of the light of the other wavelength, which is measured at the same timing as that at which the intensity of the light of the other wavelength is determined to be the abnormal value, from the object for generating the spectrum.

In the above-described measurement device, the spectroscopic unit may be configured to disperse light having a wavelength corresponding to the time period for which the light emitting element is turned on.

In the above-described measurement device, the spectroscopic unit may be configured to disperse the light of a plurality of wavelengths included in a predetermined range in a predetermined order.

In the above-described measurement device, the spectroscopic unit may be configured to disperse light of a plurality of wavelengths at a constant interval in a predetermined order.

In the above-described measurement device, the spectroscopic unit may be configured to disperse, in a predetermined order, light having a plurality of wavelengths with different intervals among a plurality of wavelengths included in a first range of the predetermined range and a plurality of wavelengths included in a second range of the predetermined range.

In the above-described measurement device, the spectroscopic unit may make a distance between a plurality of wavelengths included in a first range in which the specific wavelength is included in the predetermined range shorter than a distance between a plurality of wavelengths included in a second range in which the specific wavelength is not included in the predetermined range.

In the above-described measurement device, the spectroscopic unit may continuously disperse a plurality of wavelengths included in a first range including a specific wavelength in a predetermined range, and may discontinuously disperse wavelengths included in other ranges.

In the above-described measurement device, the spectroscopic unit may sequentially disperse the light of a plurality of wavelengths from the shorter wavelength side.

In the above-described measurement device, the spectroscopic unit may group the plurality of wavelengths in order from the shorter wavelength into a plurality of groups each including a predetermined number, and may perform the spectroscopic operation on the light of the wavelength selected one by one from each group every time the light emitting element is turned on.

The measuring apparatus may further include a concentration measuring unit that measures the concentration of the measurement target based on the intensity of the light having the wavelength selected as the specific wavelength based on the spectrum generated by the generating unit.

The measurement device may further include a concentration measurement unit that estimates the intensity of the light of the specific wavelength emitted from the light-emitting element based on the spectrum generated by the generation unit, and measures the concentration of the measurement target based on the estimated intensity and the intensity of the light of the specific wavelength measured by the measurement unit.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the above-described measurement device, each time the light emitting element such as an LED is pulsed on, light having a different wavelength is dispersed, and the intensity of the dispersed light is acquired. The measuring device can generate a spectrum indicating the relationship between each wavelength and the intensity of light by combining the intensities of the dispersed light. As a result of such processing, the measurement device can obtain the spectrum of light received via the aqueous solution or the like to be measured without continuously lighting the LED. In addition, the measuring apparatus can secure the time required for measuring the intensity of light of each wavelength, and therefore, the accuracy of the generated spectrum can be improved.

When the spectrum thus obtained is compared with the spectrum of light emitted from the LED, the wavelength at which the substance to be measured absorbs light can be estimated. By using light having such a wavelength as the specific wavelength, the measurement apparatus can further improve the measurement accuracy of the concentration.

Drawings

Fig. 1 is a diagram illustrating a measurement method in an embodiment.

Fig. 2 is a view 1 showing an example of processing for generating a spectrum by the measuring apparatus according to the embodiment.

Fig. 3 is a view 2 showing an example of processing for generating a spectrum by the measuring apparatus according to the embodiment.

FIG. 4 is a view 3 showing an example of processing for generating a spectrum by the measuring apparatus according to the embodiment.

FIG. 5 is a view 4 showing an example of processing for generating a spectrum by the measuring apparatus according to the embodiment.

Fig. 6 is a diagram showing an outline of a measurement system in the embodiment.

Fig. 7 is a diagram showing an example of the spectroscopic apparatus according to the embodiment.

Fig. 8 is a diagram showing an example of a functional configuration of the measuring apparatus according to the embodiment.

Fig. 9 is a flowchart showing an example of the operation timing of the process of acquiring a spectrum by the measurement system according to the embodiment.

Fig. 10 is a flowchart showing an example of the operation timing of the process of measuring the concentration by the measurement system according to the embodiment.

Detailed Description

Next, embodiments will be described with reference to the drawings. In the following description, the same reference numerals are given to the common components in the embodiments, and redundant description is omitted.

In the following description, the principle of a measurement method for measuring the concentration of a measurement target based on the absorbance of the measurement target will be described as a process executed by a measurement device, and thereafter, a process for generating a spectrum of light received by such a measurement device will be described.

[ principle of measurement method ]

Conventionally, there is known a technique of measuring the concentration of an aqueous solution such as hydrochloric acid, nitric acid, phosphoric acid, ammonium hydroxide, or hydrogen peroxide based on the absorbance of the aqueous solution, by using the aqueous solution as a cleaning solution or an etching solution for a semiconductor. In short, it is considered that the concentration of each solute in the aqueous solution can be measured with high accuracy by a simple configuration by narrowing the wavelength region of the light irradiated to the aqueous solution.

Here, in the case of using a semiconductor light Emitting element such as an led (light Emitting diode), although the wavelength region of light irradiated to an aqueous solution can be narrowed compared to a halogen lamp or the like, since the wavelength band is still wide, it cannot be said that the concentration of the aqueous solution is measured with high accuracy. Further, since the wavelengths of light that is easily absorbed by substances are different, when the wavelength range of light emitted from a light source is narrowed, only the concentration of a certain solute can be measured from an aqueous solution in which a plurality of solutes are dissolved, such as a mixed acid.

In addition, when a halogen lamp is used as the light source, the light emitted from the light source is dispersed using a diffraction grating or a color filter, and the configuration of the measurement device becomes complicated. In addition, halogen lamps have a shorter life than semiconductor light emitting elements such as LEDs, and are troublesome to replace.

On the other hand, when it is known in advance what solute is dissolved in the aqueous solution, the concentration of the solute can be measured with high accuracy by using light in a wavelength band of light having a wavelength (hereinafter referred to as "specific wavelength") considered appropriate for the concentration measurement of the solute and by splitting the light received through the aqueous solution into light having a specific wavelength. In view of this, it is conceivable to use a small and inexpensive fabry-perot type spectroscope having a relatively narrow wavelength range in which light can be separated, to separate received light into light having a specific wavelength, thereby solving the problem.

[ measurement method ]

Hereinafter, the measurement method in the embodiment will be described with reference to fig. 1. Fig. 1 is a diagram illustrating a measurement method in an embodiment. Fig. 1 conceptually shows a configuration of a measurement system 1 for measuring a concentration of a solute dissolved in a sample of a liquid such as an aqueous solution.

For example, the measurement system 1 includes a light source device 2, a flow cell 3, a tunable fabry-perot spectroscopy filter 4, a light receiving element 5, and a measurement device 6.

The light source device 2 is a light source device capable of projecting light, and is realized by a light source such as a halogen lamp or an LED, for example. For example, the light source device 2 emits light of a predetermined intensity under the control of the measuring device 6. In this way, the light emitted from the light source device 2 is transmitted along the optical path OP to the light receiving element 5 via the flow cell 3 and the tunable fabry-perot spectroscopy filter 4.

Here, the light source device 2 may be any light source that can emit light in a wavelength band including a specific wavelength corresponding to each of one or both of the solutes in which the concentration is measured. For example, the light source device 2 may be implemented by an LED having a half-value width of about ± 100 nm, and in the case where the solute is ammonia or hydrogen peroxide, the light source may be any light source that can output light in a wavelength band of 1525 nm to 1600 nm at least with sufficient intensity.

The flow cell 3 is made of a material (e.g., quartz) transparent to the light emitted from the light source device 2, and can flow a sample such as an aqueous solution inside. The flow cell 3 may be implemented by a test tube, a cell, or the like. The flow cell 3 does not need to be entirely made of a transparent material, and an incident portion on which light emitted from the light source device 2 enters and an emitting portion from which the incident light is emitted via the sample may be made transparent.

The tunable Fabry-Perot spectroscopy filter 4 is a Fabry-Perot Interferometer (Fabry Perot Interferometer) that can change the wavelength of transmitted light, and has two half mirrors arranged in parallel. For example, the tunable fabry-perot spectroscopy filter 4 includes an upper mirror UM which is a half-mirror provided on the light source device 2 side, and a lower mirror DM which is a half-mirror provided on the light receiving element 5 side. The fabry-perot tunable filter 4 controls the interval between the upper mirror UM and the lower mirror DM, thereby transmitting light having a wavelength corresponding to the interval between the upper mirror UM and the lower mirror DM from among the light received via the flow cell 3. For example, the tunable fabry-perot spectroscopy filter 4 transmits light of a specific wavelength corresponding to a solute from among the light received through the sample, in accordance with the control from the measurement device 6.

The light receiving element 5 is an element that measures the intensity of received light when receiving light transmitted through the tunable fabry-perot spectroscopy filter 4. For example, the light source is implemented by a photoelectric element such as a photodiode. For example, when the light receiving element 5 receives the transmitted light, it generates an electric signal indicating the intensity of the received light, and transmits the generated electric signal to the measurement device 6.

The measuring device 6 measures the concentration of the solute contained in the sample based on the intensity of the light received by the light receiving element 5. For example, the measurement device 6 controls the light source device 2 to emit light in a wavelength band including a specific wavelength, and controls the tunable fabry-perot spectroscopy filter 4 to transmit light of the specific wavelength. The measuring device 6 measures the intensity of the light of the specific wavelength received by the light receiving element 5.

Here, the measuring apparatus 6 takes the intensity of light received by the light receiving element 5 in a state where no sample is present in the flow cell 3 as I₀The intensity of light received by the light receiving element 5 in the state where the sample is present in the flow cell 3 is measured as I₁And (4) carrying out measurement. Then, the measuring apparatus 6 calculates the absorbance a of the sample at a specific wavelength using the following formula (1), and measures the concentration of the solute contained in the sample based on the calculated absorbance a.

[ formula 1]

A＝-log(I₁/I₀) …(1)

The measuring device 6 may calculate a logarithm of a ratio of the intensity of the light received by the light receiving element 5 in a state where only the predetermined solvent in which the solute is not dissolved exists in the flow cell 3 to the intensity of the light received by the light receiving element 5 in a state where the solution in which the solute is dissolved in the predetermined solvent exists in the flow cell 3, and calculate a value obtained by inverting a sign of the calculated logarithm as the absorbance of the solute with respect to the solvent.

[ example of measurement method ]

An example of a process for measuring the concentration of a solute contained in a sample based on the absorbance of the sample will be described below. In the following description, ammonia (NH) is used as the coupling agent₃) And hydrogen peroxide (H)₂O₂) The aqueous solution of (2) is an example of a sample, but the embodiment is not limited thereto. The measuring apparatus 6 can calculate the concentration of a solute from the absorbance of a sample containing an arbitrary solute. In the following description, the intensity of transmitted light of a sample is relative to the intensity of transmitted light aloneThe logarithm of the ratio of the intensity of transmitted light of the solute in water is determined, and the value obtained by inverting the sign is used as the absorbance of the sample.

For example, ammonia has a peak of absorbance around 1530 nm, and hydrogen peroxide has a flat peak between 1500 nm and 1850 nm. Therefore, the absorption spectrum of a sample which is an aqueous solution in which ammonia and hydrogen peroxide are dissolved is considered to have peaks in both the vicinity of the peak of the absorbance of the aqueous ammonia solution and the vicinity of the peak of the absorbance of hydrogen peroxide.

Here, the measuring device 6 selects 2 specific wavelengths, and measures the concentrations of ammonia and hydrogen peroxide based on the absorbance of the sample at the selected specific wavelengths. For example, the measurement device 6 uses light having wavelengths around 1530 nm and 1600 nm as specific wavelengths based on 1500 nm, which is less susceptible to the chemical solution. More specifically, the measurement device 6 selects, as a specific wavelength, a wavelength at which a peak of absorbance of a solute appears for each solute contained in a sample. Then, the measuring device 6 measures the absorbance of the sample at the selected specific wavelength, and calculates the concentration of each solute contained in the sample based on the measured absorbance.

For example, the wavelength near the absorption peak of an aqueous ammonia solution is set to a specific wavelength λ 1, the wavelength near the absorption peak of a hydrogen peroxide solution is set to a specific wavelength λ 2, and the concentration of ammonia is set to [ NH ]₃]The concentration of hydrogen peroxide is set to [ H ]₂O₂]. Here, since the absorbance of the sample is proportional to the concentration of the solute contained in the sample if the optical path length is constant according to the lambert-beer law, the following expressions (2) and (3) are obtained if the absorbance of the sample at the specific wavelength λ 1 is a1 and the absorbance of the sample at the specific wavelength λ 2 is a 2. The coefficient a of the formula (2) is the absorption coefficient of ammonia at the specific wavelength λ 1, and the coefficient b of the formula (2) is the absorption coefficient of hydrogen peroxide at the specific wavelength λ 1. The coefficient c of formula (3) is the absorption coefficient of ammonia at a specific wavelength λ 2, and the coefficient d of formula (3) is the absorption coefficient of hydrogen peroxide at a specific wavelength λ 2.

[ formula 2]

A₁＝a[NH₃]+b[H₂O₂] …(2)

[ formula 3]

A₂＝c[NH₃]+d[H₂O₂] …(3)

Here, if expressions (2) and (3) are modified to one determinant, expression (4) below can be obtained. Here, P represented by formula (4) is a matrix of absorption coefficients as represented by formula (5). In the following description, P may be referred to as a coefficient matrix.

[ formula 4]

[ formula 5]

Therefore, the measuring apparatus 6 can determine the concentration [ NH ] of ammonia from the absorbance A1 of the sample at the specific wavelength λ 1 and the absorbance A2 of the sample at the specific wavelength λ 2 by the following formula (6)₃]And concentration of hydrogen peroxide [ H ]₂O₂]。

[ formula 6]

[ principle of method for generating Spectrum ]

Next, the principle of the process of generating a spectrum by the measurement device 6 will be described. For example, when the measurement target is a liquid such as an aqueous solution, the wavelength of light that the measurement target easily absorbs changes depending on the type or ratio of the solute or the solvent. In addition, when the solute or the solvent changes or when the concentration changes, a new specific wavelength may need to be selected in order to measure the concentration of the measurement target with high accuracy. This problem is also present when the object to be measured is water vapor or a mixed gas. Therefore, in order to improve the accuracy of concentration measurement, it is important to select a wavelength of light whose absorbance easily changes depending on the concentration of the measurement target as the specific wavelength.

As an index for selecting such a specific wavelength, an intensity spectrum (hereinafter, sometimes collectively referred to as "spectrum") of transmitted light transmitted through a measurement object or a spectrum of reflected light reflected by the measurement object is considered useful. For example, it is considered that the concentration of the object to be measured can be measured with high accuracy by comparing the spectrum of the emitted light emitted from the light source device 2 with the spectrum of the transmitted light and setting the wavelength having a larger intensity variation as the specific wavelength. In this way, in order to measure the concentration of the measurement target with high accuracy, the spectrum of the transmitted light or the reflected light can be an index for selecting a specific wavelength.

On the other hand, when the intensity of the light emitted from the light source device 2 is increased, the measurement accuracy can be improved. In addition, when the lighting time of the light source device 2 is suppressed, the deterioration of the light source device 2 can be prevented, and the replacement time can be extended. Therefore, a method is considered in which the light source device 2 is intermittently pulsed only for a period sufficient for measuring the absorbance of the sample, instead of continuously turning on the light source device 2.

However, when the light source device 2 is pulsed on, there is a possibility that the spectrum of the transmitted light cannot be acquired properly. For example, when a spectrum is acquired for a wavelength band having a certain width, it is considered that a more appropriate specific wavelength can be selected. However, when the light source device 2 is pulsed on, the number of wavelengths at which the intensity of light can be obtained during the period when the light source device 2 is turned on is limited.

Therefore, the measurement device 6 pulse-lights the light source device 2, and disperses light having a wavelength different from at least the dispersed wavelength, and measures the intensity of the dispersed light. For example, each time the light source device 2 is turned on, the measurement device 6 disperses light of a plurality of wavelengths including light of a wavelength different from that of the previous dispersed light, and measures the intensity of the dispersed light. Then, the measurement device 6 generates a spectrum of a wavelength band having a certain width by synthesizing the measurement results.

For example, the wavelength bands to be generated as spectra are λ(s) to λ (l). In such a wavelength band, if the number of samples to be measured of the intensity of light is n, the wavelengths to be measured of the intensity of light are λ (1) to λ (n). Here, the wavelengths λ (1) to λ (n) are a plurality of wavelengths having a certain interval (e.g., (l-s)/n). Further, if x is a time during which the intensity of light of each wavelength can be measured with predetermined accuracy, and y is a primary lighting time during pulse lighting, the number of wavelengths during which the intensity can be measured during the primary lighting time is y/x. Here, the lighting time y may be a time during which the light source device 2 can emit light of a stable intensity, instead of the time during which the light source device 2 is turned on and off.

As a result, if the number of times the light source device 2 needs to be turned on to generate a spectrum is m when the number of wavelengths to be generated is n, m is n × x/y times. Therefore, the measurement device 6 measures the intensity of the split light while changing the split light by n/m every time the light source device 2 is turned on. In other words, each time the light source device 2 is turned on, the measurement device 6 measures the intensities of the light of a plurality of wavelengths included in a predetermined range by splitting the light of the number of wavelengths corresponding to the time for turning on the light source device 2.

Here, the measurement device 6 may measure the intensity of the split light by splitting λ (1) to λ (n) in an arbitrary order. For example, the measurement device 6 may generate a spectrum of transmitted light by splitting λ (1) to λ (n) in order of wavelength, measuring the intensities of the split lights, and combining the intensities of the measured lights.

For example, fig. 2 is a view 1 showing an example of processing for generating a spectrum by the measuring apparatus according to the embodiment. In the example shown in fig. 2, the measurement target is represented by wavelengths λ (1) to λ (36) included in a wavelength band of 0 nm to 280 nm. In the example shown in fig. 2, an example of processing in which 6 wavelengths are measured in 1 pulse lighting is described. The wavelengths λ (1) to λ (36) are equally spaced wavelengths.

In the example shown in fig. 2, the intensity of light measured in the 1 st pulse is indicated by a diamond symbol, the intensity of light measured in the 2 nd pulse is indicated by a triangle symbol, and the intensity of light measured in the 3 rd pulse is indicated by a meter symbol. In the example shown in fig. 2, the intensity of light measured in the 4 th pulse is indicated by a square symbol, the intensity of light measured in the 5 th pulse is indicated by a cross symbol, and the intensity of light measured in the 6 th pulse is indicated by a circle symbol.

For example, the measuring device 6 disperses the wavelengths λ (1) to λ (6) during the lighting period of the 1 st pulse, and measures the intensity of each dispersed light. Similarly, the measurement device 6 disperses the wavelengths of λ (7) to λ (12) in the lighting period of the 2 nd pulse, the wavelengths of λ (13) to λ (18) in the lighting period of the 3 rd pulse, the wavelengths of λ (19) to λ (24) in the lighting period of the 4 th pulse, the wavelengths of λ (25) to λ (30) in the lighting period of the 5 th pulse, and the wavelengths of λ (31) to λ (36) in the lighting period of the 6 th pulse.

Then, the measuring device 6 measures the intensity of the light of each wavelength after the spectroscopy. As a result, the measurement device 6 generates spectra of λ (1) to λ (6) using the lighting period of the 1 st pulse, spectra of λ (7) to λ (12) using the lighting period of the 2 nd pulse, and spectra of λ (13) to λ (18) using the lighting period of the 3 rd pulse. The measurement device 6 generates spectra of λ (19) to λ (24) using the lighting period of the 4 th pulse, spectra of λ (25) to λ (30) using the lighting period of the 5 th pulse, and spectra of λ (31) to λ (36) using the lighting period of the 6 th pulse.

The measurement device 6 generates a synthesized spectrum obtained by synthesizing the respective spectra, thereby obtaining spectra of wavelengths λ (1) to λ (36).

Such a synthesized spectrum is used when the measuring device 6 measures the concentration of the measurement target. For example, the measurement device 6 may select a specific wavelength used for measuring the concentration of the measurement target based on the synthesized spectrum. The measurement device 6 may regard the combined spectrum as the spectrum of the light emitted from the light source device 2 (hereinafter, may be referred to as "emission spectrum"), calculate the absorbance of the measurement object from the intensity of the light of a specific wavelength in the emission spectrum and the intensity of the light of the specific wavelength measured via the measurement object, and calculate the concentration from the calculated absorbance.

[ correction when generating a Spectrum ]

Here, the measurement device 6 measures the intensity of light λ (1) to λ (n) at the timing when different pulses are turned on. Therefore, when air bubbles are mixed in the sample or when data transmitted from the light receiving element 5 is erroneous, the accuracy of the synthesized spectrum may be lowered. Therefore, the measurement device 6 may generate a spectrum in which the intensity of light of each wavelength is corrected based on the difference between the intensities of light of the re-measurement wavelengths by re-splitting light of the re-measurement wavelengths with any one of the wavelengths split by the light-emitting element at the previous lighting time as the re-measurement wavelength.

For example, fig. 3 is a view 2 showing an example of processing for generating a spectrum by the measuring apparatus according to the embodiment. In the example shown in fig. 3, similarly to the example shown in fig. 2, the wavelengths λ (1) to λ (36) are described as the measurement targets.

Here, in the example shown in fig. 3, the intensity of light measured in each pulse is represented by the same symbol as in fig. 2, and the re-measurement wavelength is represented by a symbol in which 2 symbols are superimposed. For example, the wavelength to be measured in the 2 nd pulse is represented by a symbol in which the intensity of light measured in the 1 st pulse and the intensity of light measured in the 2 nd pulse are superimposed.

For example, the measuring device 6 disperses the wavelengths λ (1) to λ (6) during the lighting period of the 1 st pulse, and measures the intensity of each dispersed light. Next, the measurement device 6 re-disperses λ (6) dispersed in the 1 st pulse as a re-measurement wavelength in addition to the wavelengths of λ (7) to λ (12) in the lighting period of the 2 nd pulse. In addition, as long as the measurement device 6 uses at least one of λ (1) to λ (6) that has been dispersed at the previous time (i.e., the 1 st pulse) as the re-measurement wavelength, the re-measurement wavelength may be any number of arbitrary wavelengths.

Similarly, the measurement device 6 splits λ (12) split in the 2 nd pulse into a wavelength for re-measurement in addition to the wavelengths of λ (13) to λ (18) during the lighting period of the 3 rd pulse. In addition, the measurement device 6 splits λ (18) split in the 3 rd pulse into a wavelength of λ (19) to λ (24) as a re-measurement wavelength in the lighting period of the 4 th pulse. In addition, the measurement device 6 splits λ (24) split in the 4 th pulse into a wavelength of λ (25) to λ (30) as a re-measurement wavelength in the lighting period of the 5 th pulse. In addition, the measurement device 6 splits λ (30) split in the 5 th pulse into a wavelength of λ (31) to λ (36) as a re-measurement wavelength in the lighting period of the 6 th pulse.

Then, the measuring device 6 measures the intensity of the light of each wavelength after the spectroscopy to generate a synthesized spectrum. Here, the measuring device 6 compares the intensities of the light having the re-measured wavelengths, and performs correction according to the comparison result. For example, the measurement device 6 determines whether or not the difference between the intensity of light of λ (6) measured in the 1 st pulse and the intensity of light of λ (6) as the re-measurement wavelength in the 2 nd pulse is within a predetermined range. When the difference between the respective intensities is within a predetermined range, the measurement device 6 uses the intensities of light at λ (7) to λ (12) measured in the 2 nd pulse as they are as the values of the synthesized spectrum.

Similarly, the measurement device 6 determines whether or not the difference between the intensity of light of λ (12) measured in the 2 nd pulse and the intensity of light of λ (12) as the re-measurement wavelength in the 3 rd pulse is within a predetermined range, and when the difference between the intensities is within the predetermined range, the intensities of light of λ (13) to λ (18) measured in the 3 rd pulse are used as the value of the synthesized spectrum as they are. The measuring device 6 determines whether or not the difference between the intensity of light of λ (18) measured in the 3 rd pulse and the intensity of light of λ (18) as the re-measurement wavelength in the 4 th pulse is within a predetermined range, and if the difference between the intensities is within the predetermined range, the intensities of light of λ (19) to λ (24) measured in the 4 th pulse are used as the values of the synthesized spectrum as they are.

The measuring device 6 determines whether or not the difference between the intensity of light at λ (24) measured in the 4 th pulse and the intensity of light at λ (24) as the re-measurement wavelength in the 5 th pulse is within a predetermined range. Here, in the example shown in fig. 3, the difference between the intensity of light of λ (24) measured in the 4 th pulse and the intensity of light of λ (24) as the re-measurement wavelength in the 5 th pulse is very different. Therefore, the measurement device 6 determines that the intensities of the light beams of λ (25) to λ (30) measured in the 5 th pulse are abnormal values, and excludes the intensities of the light beams of λ (25) to λ (30) measured in the 5 th pulse from the synthesis target. When it is determined that the intensity of light measured in the 5 th pulse is an abnormal value, it is difficult to determine whether or not λ (31) to λ (36) measured in the 6 th pulse are abnormal values, but they may be included in the synthesis target as they are. As a result, as shown in fig. 3, the measurement device 6 can obtain a synthesized spectrum indicating the intensity of light having wavelengths λ (1) to λ (24), λ (31) to λ (36).

[ Change in correction ]

In the above example, the measurement device 6 sets the wavelength measured at the last time among the wavelengths measured at the 1 st time as the re-measurement wavelength at the 2 nd time next to the 1 st time, and excludes the measurement result at the 2 nd time from the object to be synthesized when the intensity change of the light at the re-measurement wavelength is large. However, the embodiment is not limited thereto.

For example, the measurement device 6 may split light of a plurality of wavelengths including a predetermined re-measurement wavelength every time the light emitting element is turned on, and generate a spectrum in which the intensity of light of each wavelength is corrected based on the difference between the intensities of light of the re-measurement wavelengths. More specifically, the measurement device 6 selects a predetermined wavelength as λ (0), and measures the intensity of light of each wavelength including λ (0) at each time. The measurement device 6 may compare the intensities of light at λ (0) measured at the respective times, and exclude the measurement object at the time when the intensities of light at λ (0) are greatly different from those at the other times from the synthesis object. For example, the measurement device 6 may exclude the measurement result of the 5 th pulse as an abnormal value from the synthesis target when the intensity of the light of λ (0) measured in the 5 th pulse is significantly different from the intensities of the light of λ (0) measured in the 1 st to 4 th and 6 th pulses.

The measurement device 6 may also consider the measurement results of the preceding and following times. For example, the measurement device 6 may exclude the measurement result of the 2 nd pulse as an abnormal value from the synthesis target when the intensity of light at λ (6) as the re-measurement wavelength in the 2 nd pulse is deviated from the intensity of light at λ (6) as measured in the 1 st pulse and the intensity of light at λ (12) as measured in the 2 nd pulse is deviated from the intensity of light at λ (12) as the re-measurement wavelength in the 3 rd pulse.

The measuring device 6 may correct the value of the intensity of the light measured at each time point based on the difference in the intensity of the light measured at each time point. That is, the measurement device 6 may perform synthesis in consideration of a deviation corresponding to a difference in the intensity of light. More specifically, the measurement device 6 may correct the value of the measurement result estimated to be an abnormal value based on the measurement result estimated not to be an abnormal value.

For example, when the difference between the intensity of light at λ (6) in the 1 st pulse and the intensity of light at λ (6) in the 2 nd pulse is within a predetermined range, the measurement device 6 determines that neither the 1 st pulse nor the 2 nd pulse is an abnormal value. Then, when the difference between the intensity of light at λ (12) in the 2 nd pulse and the intensity of light at λ (12) in the 3 rd pulse exceeds a predetermined threshold, the measurement device 6 calculates the correction amount of the measurement result of the 3 rd pulse based on the intensity of light at λ (12) in the 2 nd pulse. For example, the measurement device 6 may use the difference between the intensity of light of λ (12) in the 3 rd pulse and the intensity of light of λ (12) in the 2 nd pulse as the correction amount, or may use the ratio of the values of the respective intensities as the correction amount. Then, the measuring device 6 may apply the calculated correction amount to the measurement result of the 3 rd pulse to generate a composite spectrum.

For example, the measurement device 6 may determine whether or not the measurement result at each time is an abnormal value using the value of λ (0), and apply correction corresponding to the difference in the intensity of light at the remeasurement wavelength such as λ (6) or λ (12). That is, the measurement device 6 may perform any of the various processes described above in combination.

[ wavelength of light dispersed at each time ]

In the above example, the measuring device 6 disperses the light having the wavelengths λ (1) to λ (36) by a predetermined amount in order from the shorter wavelength, and measures the intensity of the light. However, the embodiment is not limited thereto. For example, the measurement device 6 may perform the spectroscopy and the measurement in order from the longer wavelength side. The measurement device 6 may perform the spectroscopy and the measurement in a random order. The measurement device 6 may perform light splitting of the number of wavelengths corresponding to the length of time for which the light source device 2 is pulsed on.

The measurement device 6 may intermittently perform the spectroscopy and measurement of light of each wavelength, thereby suppressing the loss of the amount of information when an abnormal value occurs. For example, the measurement device 6 may divide the plurality of wavelengths into a plurality of groups each including a predetermined number in order from the shorter wavelength, and may divide light of a wavelength selected one by one from each group every time the light emitting element is turned on.

For example, fig. 4 is a view 3 showing an example of processing for generating a spectrum by the measuring apparatus according to the embodiment. In the example shown in fig. 4, the intensity of light measured in each pulse is represented by the same reference numeral as in fig. 2. For example, the measurement device 6 classifies the wavelengths λ (1) to λ (36) into 6 groups of λ (1) to λ (6), λ (7) to λ (12), λ (13) to λ (18), λ (19) to λ (24), λ (25) to λ (30), and λ (31) to λ (36). Then, the measurement device 6 selects wavelengths from each group one by one, and disperses the light of the selected 6 wavelengths at each time.

For example, the measurement device 6 measures the intensity of light by splitting the wavelengths λ (1), λ (7), λ (13), λ (19), λ (25), and λ (31) in the 1 st pulse. The measuring device 6 measures the intensity of light by splitting the wavelengths λ (2), λ (8), λ (14), λ (20), λ (26), and λ (32) in the 2 nd pulse. That is, when the wavelengths λ (1) to λ (n) are obtained by m-time pulse lighting, the measurement device 6 disperses light having a wavelength of λ (p), λ (p + n/m), λ (p +2n/m) … λ (p + ((n/m) -1) (n/m)) in the p-th pulse lighting, and measures the intensity of the light. As a result of such processing, the measurement device 6 can obtain a synthesized spectrum indicating the intensity of light of each wavelength, as shown in fig. 4.

Here, fig. 5 is a 4 th view showing an example of processing for generating a spectrum by the measuring apparatus according to the embodiment. In the example shown in fig. 5, similarly to the example shown in fig. 4, an example is described in which the intensity of light of each wavelength is intermittently measured. In the example shown in fig. 5, the intensity of light measured in each pulse is represented by the same symbol as in fig. 2, and the wavelength of about 180 nm is measured as the re-measurement wavelength λ (0) as indicated by the star-shaped symbol.

For example, the measurement device 6 compares the intensities of light at λ (0) measured at each time, and specifies a time at which the intensities of light measured at other times are greatly deviated. Here, in the example shown in fig. 5, the intensity of light of λ (0) measured in the 5 th pulse greatly deviates from the intensity of light measured at other times. In this case, the measurement device 6 excludes the measurement result of the 5 th pulse from the synthesis target as an abnormal value. Then, the measurement device 6 generates a synthesized spectrum in which the measurement results of the 1 st to 4 th pulses and the 6 th pulse are synthesized.

Here, in the example shown in fig. 5, intermittent wavelengths are selected at each time, and the intensity of light of the selected wavelengths is measured. As a result, even if the 5 th pulse measurement target is excluded from the synthesis result, a synthesized spectrum that can be analogized to some extent to the entire spectrum can be obtained. In other words, the measurement device 6 can prevent the loss of the measurement result of the entire certain wavelength band when an abnormal value occurs by intermittently operating the wavelength measured at each time. As a result, the measuring device 6 can suppress a decrease in the accuracy of the synthesized spectrum.

[ embodiment ]

An example of an embodiment in which the concentration of the sample is measured by the above-described measurement method will be described below with reference to fig. 6. Fig. 6 is a diagram showing an outline of a measurement system in the embodiment. In the example shown in fig. 6, the measurement system 10 includes an LED11,

optical fibers

12 and 16, a light projecting unit 13, a flow cell 14, a light receiving unit 15, a spectroscopic unit 17, and a measurement device 100.

The LED11 is a light source of the light source device 2 and emits light including a specific wavelength corresponding to the solute. For example, the LED11 is a light-emitting element capable of outputting light having a half-value width of about 100 nm.

The optical fiber 12 is an optical fiber for transmitting light emitted from the LED to the light projecting section 13, and is implemented by, for example, a single-phase optical fiber. The light emitter 13 receives the light emitted from the LED11 through the optical fiber 12, and then emits the received light to the flow cell 14.

The flow cell 14 is a flow cell through which the sample flows. For example, in the example shown in fig. 6, the semiconductor cleaning liquid supplied from the cleaning liquid supply device CP to the cleaning device CM flows as a sample in the contents of the flow cell 14.

The light receiving unit 15 receives the light projected from the light projecting unit 13 via the sample in the flow cell 14. Then, light receiving unit 15 outputs the received light to optical fiber 16. The optical fiber 16 is an optical fiber for transmitting the light output from the light receiving unit 15 to the optical splitter 17, and is implemented by, for example, a single-phase optical fiber, as in the case of the optical fiber 12. The configuration shown in fig. 6 is merely an example. For example, the measurement system 10 may not include the

optical fibers

12 and 16, the light projecting unit 13, and the light receiving unit 15.

The light splitting device 17 is a fabry-perot type light splitting device that, when light emitted from the LED11 is received via a sample, splits the received light. For example, the spectroscopic device 17 disperses the light received from the optical fiber 16 into light of a predetermined specific wavelength.

For example, fig. 7 is a diagram showing an example of the spectroscopic apparatus according to the embodiment. As shown in fig. 7, the spectroscopic unit 17 includes, in order from the side receiving the light from the optical fiber 16, a band pass filter 17a, an upper mirror 17b, an air gap 17c, a lower mirror 17d, a substrate 17e, a spacer 17f, a light receiving element 17g, and a wiring substrate 17 h. The upper mirror 17b, the air gap 17c, the lower mirror 17d, and the substrate 17e correspond to the tunable fabry-perot spectroscopy filter 4 shown in fig. 1, and the light receiving element 17g corresponds to the light receiving element 5 shown in fig. 1.

The band pass filter 17a is a filter that attenuates the intensity of light outside a predetermined wavelength band among the light incident from the optical fiber 16. The upper mirror 17b is a half mirror disposed on the side of the bandpass filter 17a, and has a diaphragm (thin film) structure. The lower mirror 17d is a half mirror facing the upper mirror 17b, and is disposed on the light receiving element 17g side. The air gap 17c is a space between the upper mirror 17b and the lower mirror 17 d. In addition, the substrate 17e is a substrate of a fabry-perot spectrometer, and has transmittance.

The spacer 17f is a spacer for maintaining the gap between the substrate 17e and the light receiving element 17 g. The light receiving element 17g is a photodiode provided on the wiring board 17h, and measures the intensity of light received via the board 17 e. The wiring board 17h transmits an electric signal indicating the intensity of the light measured by the light receiving element 17g to the measurement device 100.

Here, the measuring apparatus 100 applies a voltage between the upper mirror 17b and the lower mirror 17d to generate an electrostatic attractive force between the upper mirror 17b and the lower mirror 17d, and adjusts the distance of the air gap 17c by bringing the upper mirror 17b of the diaphragm structure closer to the lower mirror 17 d. The upper mirror 17b and the lower mirror 17d can transmit light having a wavelength corresponding to the distance of the air gap 17c, and the transmitted light having the wavelength is incident on the light receiving element 17g via the substrate 17 e.

More specifically, the measurement device 100 changes the distance of the air gap 17c by changing the voltage applied between the upper mirror 17b and the lower mirror 17d in a stepwise manner (or continuously) each time the light source device 2 is turned on. As a result, the spectroscopic device 17 disperses 1 or a plurality of light beams having different wavelengths each time the light source device 2 is turned on, and measures the intensity of the dispersed light beams.

The structure of the spectrometer 17 shown in fig. 7 is merely an example. In the measurement system 10, any spectrometer may be used as long as the incident light is split into specific wavelengths by using the principle of fabry-perot interferometer, in addition to the light splitting device 17 shown in fig. 7.

The description is continued with reference to fig. 6. The measuring apparatus 100 measures the concentration of the sample based on the intensity of the light split by the light splitting apparatus 17. For example, the measurement device 100 measures the concentration of a solute dissolved in an aqueous solution flowing through the flow cell 14.

[ example of functional configuration of measuring apparatus ]

An example of the functional configuration of the measurement device 100 will be described below with reference to fig. 8. Fig. 8 is a diagram showing an example of a functional configuration of the measuring apparatus according to the embodiment. As shown in fig. 8, the measurement device 100 includes a light source control unit 110, a spectroscopic control unit 120, a light receiving control unit 130, an input unit 140, an output unit 150, a storage unit 160, and a control unit 170.

The light source controller 110 is a control device that controls the lighting of the LED11 according to the control from the controller 170, and is implemented by, for example, a lighting circuit of the LED 11. For example, the light source control unit 110 controls the LED11 to emit light of a predetermined wavelength band at a predetermined intensity. The light source control unit 110 may include various control means to make the wavelength band or intensity of the light emitted from the LED11 constant.

Here, the light source controller 110 does not continuously turn on the LED11 to measure the concentration of the sample, but turns on the LED11 in a pulse manner for a period sufficient to measure the absorbance of the sample. Similarly, when the spectrum is acquired, the light source control unit 110 intermittently pulse-lights the LED 11. As a result of such control, the light source control unit 110 can suppress the lighting time of the LED11, and therefore can prevent deterioration of the LED11 and extend the replacement timing of the LED 11.

The spectroscopic control unit 120 is a control device that controls the spectroscopic apparatus 17 in accordance with control from the control unit 170, and is realized by, for example, a control circuit of the spectroscopic apparatus 17. For example, the spectral control unit 120 appropriately controls the wavelength of light received by the light receiving element 17g by controlling the voltage applied between the upper mirror 17b and the lower mirror 17d of the spectroscopic device 17.

More specifically, when the concentration of the sample is acquired, the spectroscopic control unit 120 controls the voltage applied between the upper mirror 17b and the lower mirror 17d of the spectroscopic device 17 so as to disperse the light having the specific wavelength. In addition, when acquiring the spectrum, the spectral control unit 120 controls the voltage so that light having a different wavelength is dispersed each time the LED11 is turned on.

The light reception controller 130 is a controller for measuring the intensity of the dispersed light in accordance with the control from the controller 170, and is realized by, for example, a control circuit of the light receiving element 177 included in the spectrometer 17. For example, when receiving an electric signal indicating the intensity of light measured by the spectroscopic device 17, the light reception controller 130 converts the received electric signal into a numerical value indicating the intensity of light, and notifies the controller 170 of the converted numerical value.

The input unit 140 is an input device that receives an operation from a user, and is implemented by a keyboard, a mouse, or the like, for example. The output unit 150 is an output device for outputting the measurement result of the measurement device 100, and is implemented by, for example, a liquid crystal monitor, a printer, or the like.

The storage unit 160 is a storage device for storing various information, and is implemented by, for example, a semiconductor Memory element such as a ram (random Access Memory) or a Flash Memory, or a storage device such as a hard disk or an optical disk. For example, various measurement records, an absorption coefficient or a coefficient matrix set in advance for each group of a solute (for example, ammonia, hydrochloric acid, hydrogen peroxide, or the like) to be measured and a specific wavelength, and the like are registered in the storage unit 160.

The control unit 170 executes various programs stored in a storage device inside the measurement device 100 by a processor such as a cpu (central Processing unit), an mpu (micro Processing unit), or the like, using a RAM or the like as a work area. The control unit 170 may be implemented by an Integrated circuit such as an asic (application Specific Integrated circuit) or an fpga (field Programmable gate array).

In the example shown in fig. 8, the control unit 170 includes an acquisition unit 171, a generation unit 172, a calculation unit 173, and a supply unit 174. The acquisition unit 171 controls the LED11 and the spectroscopic device 17 to acquire the intensity of the light having the specific wavelength that has been dispersed by the spectroscopic device 17 through the sample.

For example, when receiving selection of a target (measurement target) for measuring the concentration of solute or the like from the input unit 140, the acquisition unit 171 acquires the light intensity of a specific wavelength corresponding to the measurement target selected from the light passing through the sample. For example, when ammonia and hydrogen peroxide are selected, the acquisition unit 171 selects a specific wavelength corresponding to ammonia and a specific wavelength corresponding to hydrogen peroxide. Then, the acquisition unit 171 controls the light source control unit 110 to pulse the LED11, thereby emitting light of a wavelength band including a specific wavelength.

The acquisition unit 171 controls the spectral control unit 120 to split light of a specific wavelength from the light received from the spectroscopic device 17 via the sample during the lighting period in which the LED11 is lit. The acquisition unit 171 may switch the light of a specific wavelength to be dispersed every time the LED11 is pulsed on, or may disperse the light of all the specific wavelengths by 1-time pulse lighting. Then, the acquisition unit 171 acquires the intensity of the light of the specific wavelength measured by the spectroscopic device 17 via the light reception control unit 130. For example, the acquisition unit 171 measures the light intensity of a specific wavelength corresponding to ammonia, and then measures the light intensity of a specific wavelength corresponding to hydrogen peroxide. Then, the acquisition unit 171 acquires the measured intensity of the light of each specific wavelength.

In addition, when measuring the spectrum, the acquisition unit 171 intermittently lights the LED11, and each time the LED11 is turned on, disperses light having a wavelength different from the dispersed wavelength by dispersing light having a plurality of wavelengths. For example, the acquisition unit 171 sequentially splits the light of a predetermined number of wavelengths from the shorter wavelength side every time the light emitting element is turned on. More specifically, the acquisition unit 171 splits the wavelength of λ (1+ n (p-1)/m) to λ (pn/m) in the p-th pulse lighting when the wavelength of λ (1) to λ (n) is acquired by m-th pulse lighting.

The acquisition unit 171 may intermittently split the light of each wavelength. More specifically, when the wavelengths of λ (1) to λ (n) are obtained by m-time pulse lighting, the obtaining unit 171 splits light having wavelengths of λ (p), λ (p + n/m), λ (p +2n/m) … λ (p + ((n/m) -1) (n/m)) in the p-th pulse lighting. The acquisition unit 171 may be configured to split light of wavelengths at regular intervals or light of wavelengths at intervals having a density as the light of a plurality of wavelengths to be measured. For example, the acquisition unit 171 may split light of a plurality of wavelengths at intervals shorter than other wavelength bands for a predetermined wavelength band including a specific wavelength. Further, the acquisition unit 171 may perform re-dispersion by setting any one of a predetermined wavelength and a wavelength previously dispersed as a re-measurement wavelength every time the LED11 is turned on.

Then, the acquisition unit 171 acquires the intensity of the light of each wavelength measured by the spectroscopic device 17, and notifies the generation unit 172 of the value of each wavelength and the value indicating the intensity of the light of each wavelength. More specifically, the acquisition unit 171 notifies the generation unit 172 of the value of each wavelength dispersed by the primary pulse lighting and the value indicating the intensity of the light of each wavelength.

The generation unit 172 generates a spectrum indicating the relationship between the wavelength of the light split by the spectroscopic unit and the intensity of the light of each measured wavelength. For example, the generator 172 acquires the value of each wavelength and the value indicating the intensity of light of each wavelength from the acquirer 171. Then, the generation unit 172 generates a spectrum indicating a relationship with the acquired value indicating the intensity of the light of each wavelength. That is, the generation unit 172 synthesizes spectra of each wavelength band measured in multiple times.

Here, the generation unit 172 may perform correction based on the re-measurement wavelength when generating the spectrum. For example, the generation unit 172 calculates the difference between the intensity of light split into wavelengths to be remeasured at the time of pulse lighting for the (p + 1) -th time and the intensity of light having the same wavelength as the remeasured wavelength among the intensities of light measured at the time of pulse lighting for the (p) -th time. When the difference is within the predetermined range, the generation unit 172 may directly set the intensity of light of each wavelength measured at the time of pulse lighting of the (p + 1) th time as the object of the combination. When the difference exceeds the predetermined range, the generation unit 172 may exclude the intensity of light of each wavelength measured p-th or p + 1-th time from the synthesis target as an abnormal value.

The generation unit 172 may correct the intensity of the light measured p-th or p + 1-th time based on the difference between the intensity of the light split into the light having the same wavelength as the light having the wavelength measured at the p + 1-th pulse lighting and the intensity of the light having the same wavelength as the light having the wavelength measured at the p + 1-th pulse lighting, and synthesize the spectrum. For example, the generation unit 172 may correct the intensities of the light beams of the respective wavelengths measured at the pulse lighting of the p +1 th time so that the intensity of the light beam split into the remeasured wavelengths at the pulse lighting of the p +1 th time is equal to the intensity of the light beam having the same wavelength as the remeasured wavelength among the intensities of the light beams measured at the pulse lighting of the p +1 th time.

Then, the generating unit 172 notifies the providing unit 174 of information indicating the generated spectrum. The generation unit 172 notifies the calculation unit 173 of the generated spectrum, i.e., the synthesized spectrum, as an emission spectrum, i.e., the spectrum of the light emitted from the LED 11.

The arithmetic unit 173 measures the concentration of the measurement target based on the measured intensities of the light having the plurality of specific wavelengths. More specifically, the calculation unit 173 estimates the intensity of light of a specific wavelength emitted from the LED11 as the intensity of the emitted light from the emission spectrum generated by the generation unit 172. Then, the calculation unit 173 measures the concentration of the measurement target based on the estimated intensity of the emitted light and the intensity of the light of the specific wavelength received by the spectroscopic device 17 via the measurement target. The arithmetic unit 173 measures the densities of the plurality of measurement objects based on the measured intensities of the light having the plurality of specific wavelengths.

As a more specific example, the calculation unit 173 estimates, as the intensity of the emitted light, the intensity of light having a specific wavelength corresponding to ammonia and the intensity of light having a specific wavelength corresponding to hydrogen peroxide, respectively, from the emission spectrum. The calculation unit 173 acquires the intensity of the light of each specific wavelength dispersed by the spectroscopic device 17. Then, the calculation unit 173 calculates the absorbance at each specific wavelength from the intensity of the emitted light estimated from the emission spectrum and the intensity of the light split by the light splitting device 17, and calculates the concentrations of ammonia and hydrogen peroxide by using the above formula (6). That is, the calculation unit 173 calculates the concentration of each measurement object based on a matrix of absorption coefficients based on the conversion of the concentration of each measurement object into absorbance of a specific wavelength and the absorbance based on the intensity of the measured light of the specific wavelength.

The supply unit 174 supplies the concentration of each measurement target measured by the calculation unit 173 to the user. For example, the supply unit 174 outputs a value indicating the concentration of the measurement target selected by the user via the output unit 150. The supply unit 174 generates a table or a map indicating the spectrum generated by the generation unit 172, and outputs the generated table or map.

Further, the operator of the measurement apparatus 100 selects a specific wavelength based on the spectrum generated by the generation unit 172. In this case, the acquisition unit 171 performs spectroscopy of light having a wavelength selected as a specific wavelength based on the generated spectrum, and measures the concentration of the measurement target based on the intensity of the light after the spectroscopy. Further, even if the measurement device 100 does not receive an operation from the operator, for example, the generated spectrum may be compared with a predetermined spectrum (for example, a spectrum measured when only a solute is present or a spectrum measured when no sample is present), and light of a predetermined number of wavelengths may be automatically selected as the specific wavelength in order from the one having a larger difference.

When such a predetermined spectrum is obtained, the measurement device 100 may pulse-light the LED11, measure the intensity of light having a different wavelength each time the LED11 is pulsed, and acquire a spectrum in which the measured intensities of light are combined. For example, the measurement device 100 may perform the above-described various processes to acquire a predetermined spectrum in advance when only a solvent is present in the flow cell 14 or when a sample is not present in the flow cell 14.

[ example of operation timing in the embodiment ]

Next, an example of the operation timing of the process of acquiring the spectrum by the measurement system 10 according to the embodiment will be described with reference to fig. 9. Fig. 9 is a flowchart showing an example of the operation timing of the process of acquiring a spectrum by the measurement system according to the embodiment.

For example, the measurement device 100 determines whether or not the time is a predetermined calibration time at which calibration is performed (step S101), and waits until the calibration time when the time is not the calibration time (step S101: no). On the other hand, when the calibration time is reached (step S101: YES), the measurement device 100 pulse-lights the LED (step S102), and each time the LED is lighted, disperses the light of a plurality of wavelengths and measures the intensity of the dispersed light (step S103).

Subsequently, the measuring apparatus 100 determines whether or not the intensities of the lights of all the wavelengths have been measured (step S104), and if the intensities of the lights of all the wavelengths have not been measured (step S104: NO), the step S102 is executed again. On the other hand, when the intensities of the lights of all the wavelengths are measured (step S104: YES), the measuring apparatus 100 generates a synthesized spectrum (step S105), and supplies the generated synthesized spectrum (step S106). The measurement device 100 sets the combined spectrum as the emission spectrum, which is the spectrum of the light emitted from the LED11 (step S107), and ends the process. The measurement device 100 may execute steps S106 and S107 in an arbitrary order.

Next, an example of the operation timing of the process of measuring the concentration by the measurement system 10 according to the embodiment will be described with reference to fig. 10. Fig. 10 is a flowchart showing an example of the operation timing of the process of measuring the concentration by the measurement system according to the embodiment.

First, the measuring apparatus 100 causes the LED11 as a light source to emit light (step S201). In this case, the spectroscopic unit 17 receives light emitted from the LED11 as a light source via the measurement target (step S202). Then, the spectroscopic unit 17 measures the light having the specific wavelength after the spectroscopic operation using the tunable fabry-perot spectroscopic filter (step S203).

Next, the measurement device 100 calculates the absorbance of the sample at a specific wavelength based on the intensity and emission spectrum of the measurement light (step S204). For example, the measurement device 100 estimates the intensity of the outgoing light having a specific wavelength from the outgoing spectrum, and calculates the absorbance from the estimated intensity of the outgoing light and the intensity of the light having the specific wavelength measured via the measurement object.

Thereafter, the measurement device 100 determines whether or not all the specific wavelengths have been measured (step S205). Then, when there is a specific wavelength that has not been measured (NO in step S205), the measurement device 100 causes the spectroscopic device 17 to execute step S203. On the other hand, when all the specific wavelengths are measured (yes in step S205), the measurement device 100 calculates the concentration of the measurement object from the calculated absorbance by using the inverse matrix of the coefficient matrix for converting the absorbance at each specific wavelength into the concentration (step S206). Then, the measurement device 100 outputs the calculated concentration as a measurement result (step S207), and the process ends.

[ Effect of the embodiment ]

As described above, the measurement device 100 uses a fabry-perot type spectrometer to split light of a specific wavelength corresponding to a measurement target from light received through a sample, and measures the concentration of the measurement target based on the intensity of the split light of the specific wavelength. With such a configuration, the measurement device 100 can measure the concentration of the measurement target with high accuracy even without a configuration such as a diffraction grating or a color filter, and thus can measure the concentration of the measurement target with high accuracy with a simple configuration.

In addition, each time the LED11 is pulsed on and the LED11 is pulsed on, the measurement device 100 disperses light beams having different wavelengths from each other and measures the intensity of the dispersed light beams. Then, the measurement device 100 generates a spectrum indicating the relationship between the wavelength of the dispersed light and the intensity of the measured light of each wavelength. As a result of such processing, the measurement device 100 can obtain the spectrum of light received via the measurement object even when the LED11 is pulsed on.

[ expansion of embodiment ]

In the above description, the measurement systems 1 and 10 for measuring the concentration of the measurement target contained in the sample or acquiring the spectrum of the sample have been described, but the embodiment is not limited thereto. In the following description, a change in the processing performed by the measurement systems 1 and 10 will be described.

[ about distribution ]

In the above-described example, the measurement systems 1 and 10 split light of a plurality of wavelengths whose difference is a predetermined value (or within a predetermined range), and measure the intensity of the split light. However, the embodiment is not limited thereto. For example, the wavelengths for the measurement by the measurement systems 1 and 10 may be wavelengths having density in each wavelength band. In other words, the plurality of wavelengths to be spectrally split by the measurement device 6 may be wavelengths having a constant value or wavelengths having a density at intervals.

For example, the measurement systems 1 and 10 set a range in which a detailed spectrum is desired (for example, a range including a predicted specific wavelength) in the entire wavelength band to be measured as a first range, and set other ranges as a second range. The measurement systems 1 and 10 may select a plurality of wavelengths having a first predetermined value in interval from the wavelength band included in the first range as the measurement target, and select a plurality of wavelengths having a second predetermined value larger than the first predetermined value in interval from the wavelength band included in the second range as the measurement target.

The measurement systems 1 and 10 may be configured to continuously change the wavelength split by the tunable fabry-perot splitting filter 4 in the first range and discontinuously change the wavelength split by the tunable fabry-perot splitting filter 4 in the other ranges. Further, the continuous change of the wavelength of the light as the object of the light splitting is included, for example, with the accuracy with which the tunable fabry-perot spectroscopy filter 4 can split the light.

In this way, the measurement systems 1 and 10 may change the wavelength to be measured at shorter intervals in a range where a spectrum is desired to be obtained with higher accuracy, and change the wavelength to be measured at longer intervals in a range where accuracy is not required. By performing such processing, the measurement systems 1 and 10 can obtain a more practical spectrum.

Even when there is a density in the intervals of the wavelengths of the light to be split, the measurement systems 1 and 10 may split the light of a predetermined number of wavelengths in order from the shorter wavelength side every time the light source is turned on, or may split the light of each wavelength intermittently. The measurement systems 1 and 10 may be configured to split light of a predetermined number of wavelengths in order from the longer wavelength every time the light source is turned on. That is, the measurement systems 1 and 10 may divide the plurality of wavelengths to be measured into a plurality of groups, and each time the light source is turned on, the light of the wavelength of each group is divided and the intensity of the light is measured, and the light of each wavelength may be divided in an arbitrary order.

[ reflection light ]

In the above examples, the measurement systems 1 and 10 split the light transmitted through the sample, and measure the intensity of the split light. However, the embodiment is not limited thereto. For example, the measurement systems 1 and 10 may split light from the reflected light of the sample, and generate a spectrum and measure the concentration based on the intensity of the split light. That is, the light received via the measurement object may be a concept including not only transmitted light but also reflected light.

[ As to the sample ]

The measurement systems 1 and 10 can acquire spectra or measure concentrations using not only an aqueous solution in which various solutes are dissolved but also a solution such as an organic solvent in which various solutes are dissolved. In this case, the measurement systems 1 and 10 may use the absorbance calculated by using the formula (1) according to the ratio between the absorbance of the solvent and the absorbance of the solute. The measurement systems 1 and 10 may measure the concentration of any gas in the gases contained in the sample or acquire the spectrum of the sample using not only the solution but also various gases such as a mixed gas as the sample. The measurement systems 1 and 10 may measure the concentration of a substance as a solvent instead of the concentration of a solute.

[ constitution of the device ]

The device configuration of the measurement systems 1 and 10 is not limited to the above description. For example, the measurement device 6 may be a device that includes the light source device 2, the tunable fabry-perot spectroscopy filter 4, and the light receiving element 5, and measures the concentration of the measurement target in the sample in the flow cell 3 or acquires a spectrum.

The above description has been given of the embodiments by way of example, and the present embodiments are not limited to the above description. The configuration and details of the embodiments can be implemented in other embodiments in which various modifications and improvements are possible based on the knowledge of those skilled in the art, including the embodiments described in the disclosure of the invention. In addition, the embodiments can be combined and implemented arbitrarily within a range not to be contradicted.

Description of the symbols

1. 10 measurement system

2 light source device

3. 14 flow cell

Tunable filter for 4-Fabry-Perot spectroscopy

5. 177 light-receiving element

6. 100 measuring apparatus

11 LED

12. 16 optical fiber

13 light projecting part

15 light receiving part

17 light splitting device

110 light source control part

120 spectral control part

130 light receiving control part

140 input unit

150 output part

160 storage unit

170 control part

171 acquisition part

172 generation part

173 arithmetic unit

174 and a supply section.

Claims

1. A measurement device is characterized by comprising:

a light source unit that emits light including a specific wavelength corresponding to a measurement target of density by intermittently lighting the light emitting element;

a spectroscopic unit that, when the light emitting element is turned on, disperses at least light having a wavelength different from a wavelength of the dispersed light from the light received via the measurement object;

a measuring unit that measures the intensity of the light split by the splitting unit; and

and a generation unit that generates a spectrum indicating a relationship between the wavelength of the light split by the splitting unit and the intensity of the light of each wavelength measured by the measurement unit.

2. The assay device according to claim 1,

the light splitting part is a Fabry-Perot type light splitting part.

3. The assay device according to claim 1 or 2,

the light-splitting unit splits light having a predetermined number of wavelengths each time the light-emitting element is turned on.

4. The assay device according to claim 3,

the light splitting unit re-splits light having a re-measured wavelength, the re-measured wavelength being any one of wavelengths split by the light emitting element when it was last turned on,

the generating unit generates a spectrum in which the intensity of the light of each wavelength is corrected based on the difference between the intensities of the light of the re-measured wavelengths.

5. The assay device according to claim 3,

the spectroscopic unit disperses light of a plurality of wavelengths including a predetermined re-measurement wavelength every time the light emitting element is turned on,

the generating unit generates a spectrum in which the intensity of the light of each wavelength is corrected, based on the difference between the intensities of the light of the re-measured wavelengths.

6. The assay device according to claim 4 or 5,

the generation unit determines whether or not the intensity of light of each of the re-measurement wavelengths is an abnormal value based on the difference between the intensities of light of the re-measurement wavelengths, and excludes the intensity of light of another wavelength measured at the same timing as the time when the intensity of light determined as the abnormal value is measured from the object for generating a spectrum when it is determined that the intensity of light of any one of the re-measurement wavelengths is an abnormal value.

7. The assay device according to claim 3,

the light-splitting unit splits the light having the number of wavelengths corresponding to the time for which the light-emitting element is turned on.

8. The assay device according to claim 1 or 2,

the spectroscopic unit disperses light of a plurality of wavelengths included in a predetermined range in a predetermined order.

9. The assay device according to claim 8,

the light-splitting unit splits light of a plurality of wavelengths at a predetermined interval in a predetermined order.

10. The assay device according to claim 8,

the light splitting unit splits light having a plurality of wavelengths with different intervals in a plurality of wavelengths included in a first range of the predetermined range and a plurality of wavelengths included in a second range of the predetermined range in a predetermined order.

11. The assay device according to claim 10,

the spectroscopic unit makes intervals of a plurality of wavelengths included in a first range including the specific wavelength in the predetermined range shorter than intervals of a plurality of wavelengths included in a second range not including the specific wavelength in the predetermined range.

12. The assay device according to claim 8,

the light splitting unit continuously splits a plurality of wavelengths included in a first range including the specific wavelength in the predetermined range, and discontinuously splits wavelengths included in other ranges.

13. The assay device according to claim 8,

the light-splitting unit sequentially splits the light of the plurality of wavelengths from the shorter wavelength side.

14. The assay device according to claim 8,

the light splitting section sequentially groups the plurality of wavelengths into a plurality of groups each including a predetermined number from the shorter wavelength side, and splits light of a wavelength selected one by one from each group every time the light emitting element is turned on.

15. The assay device according to claim 1 or 2,

and a density measuring unit that measures the density of the measurement target based on the intensity of the light having the wavelength selected as the specific wavelength based on the spectrum generated by the generating unit.

16. The assay device according to claim 1 or 2,

and a density measuring unit that estimates the intensity of the light of the specific wavelength emitted from the light-emitting element based on the spectrum generated by the generating unit, and measures the density of the measurement target based on the estimated intensity and the intensity of the light of the specific wavelength measured by the measuring unit.

17. An assay method for execution by an assay device, comprising:

a lighting step of intermittently lighting a light emitting element that emits light of a specific wavelength corresponding to a measurement target of density;

a spectroscopic step of, when the light emitting element is turned on, dispersing at least light having a wavelength different from a wavelength of the dispersed light from the light received through the measurement object;

a measuring step of measuring the intensity of the light split in the splitting step; and

and a generation step of generating a spectrum indicating a relationship between the wavelength of the light split in the splitting step and the intensity of the light at each wavelength measured in the measurement step.