Spectroscopic measurement device, and adjustment method thereof

Abstract

To provide a spectroscopic measurement device capable of accurately measuring even when attached to pipes of various shapes and materials without removing suspension liquids used in the pharmaceutical, food, and chemical industries from the pipe, and an adjustment method of measurement conditions.SOLUTION: The spectroscopic measurement device is a measuring device for measuring the optical spectrum of a liquid flowing through a pipe equipped with a window material. The spectroscopic measurement device has a measuring probe having a light-emitting part, a light-receiving part, and a mechanism for moving the measuring probe. The movement direction of the measuring probe includes the rotation angle for changing the probe orientation and a direction different from the axial direction of the pipe. The position of the measuring probe is adjusted by using either the S / N ratio and / or intensity of the measured value at the wavelength of interest.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] The present invention relates to a spectroscopic measurement device for spectroscopically measuring components in a suspension and an emulsion, and to an adjustment method thereof, and more particularly to a spectroscopic measurement device suitable for performing high-precision spectroscopic measurement, and a method for adjusting the optical system thereof.

[0002] A suspension generally refers to a liquid in which solid particles are dispersed in the liquid. On the other hand, an emulsion generally refers to a liquid in which liquid particles generated by emulsification or the like are dispersed in the liquid. In this specification, the term suspension will be used without distinguishing between a suspension and an emulsion. [Background technology]

[0003] The technique of measuring components in liquids spectroscopically is non-invasive and can measure the object without sampling, and therefore does not alter the object and allows for continuous measurement, so there is demand for this technique in the pharmaceutical, food and chemical industries.

[0004] Furthermore, in these fields, for example, in the pharmaceutical field, there is an increasing need to measure suspensions obtained by cell culture, and in the food field, there is an increasing need to measure suspensions of brewed products, dairy products, and the like.

[0005] As a method for spectroscopically measuring components in a liquid, for example, a method in which light is introduced into the liquid and the transmitted light is spectroscopically measured, as described in Patent Document 1. In this method, the concentration of a component in the liquid is calculated based on the amount of light absorbed at a specific wavelength.

[0006] When the liquid is transparent, the above-mentioned method can be used to measure the spectroscopic properties of the transmitted light. However, when components are suspended in the liquid, the suspended components scatter the light, weakening the intensity of the transmitted light, making it difficult to measure the transmitted light or to calculate the concentration of the components in the liquid.

[0007] In Patent Document 1, the above problem is solved by diffuse reflection measurement, in which light scattered by the suspension liquid is measured in the same direction as the incident light.

[0008] Patent Document 2 discloses a method for performing measurements without immersing the measurement part (measurement probe) in the liquid. In this method, the probe is attached to a transparent window part of a container containing the liquid to be measured, and it is possible to measure the diffuse reflected light of the liquid in the container. In this method, the probe is not immersed in the liquid, so that the adhesion of the suspension liquid to the probe does not affect the measurement.

[0009] Furthermore, in Patent Document 2, an angle is provided between the window material of the probe and the axis of the optical fiber to prevent the irradiated light reflected by the window material from being measured again by the probe. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2000-9638 A [Patent Document 2] Japanese Patent Application Publication No. 9-89657 Summary of the Invention [Problem to be solved by the invention]

[0011] In the method described in Patent Document 1, while it is possible to measure diffuse reflected light from a suspension liquid, the measurement part is immersed in the liquid to be measured, and since the measurement part has a complicated structure, there was a concern that the suspension liquid would adhere to the measurement part and contaminate it, making the measurement difficult.

[0012] Furthermore, the inventors conducted a detailed study of the method described in Patent Document 2 and found that, in order to perform highly accurate spectroscopic measurements, it is necessary to take into account not only the influence of the irradiated light reflected from the surface of the window material, but also the reflected light from the surface where the window material comes into contact with the liquid, and the light absorption by the window material that occurs depending on the distance when light passes through the window material.

[0013] The reflectance of the surface where the window material comes into contact with the liquid is due to the difference in refractive index between the window material and the liquid. Furthermore, the light absorption when light passes through the window material varies depending on the structure of the window material, such as its thickness and curvature, and the angles at which the light is incident and received.

[0014] On the other hand, production lines in various fields use piping of various shapes and materials, and there was a concern that designing and manufacturing a probe structure in advance for these piping of various shapes and materials would be time-consuming and costly.

[0015] Furthermore, the directional distribution of light scattering in suspension liquids varies depending on the size of the particles in the liquid. Even when piping of the same shape and material is used, if the type of suspension liquid is changed, the optimal optical system conditions will change, making it necessary to change the probe structure.

[0016] An object of the present invention is to provide a spectroscopic measurement device and an optical system adjustment method that can be applied to production lines in various fields in which pipes of various shapes and materials are used. Another object of the present invention is to provide a spectroscopic measuring device and an optical adjustment method that can be applied even when the size of the particles suspended in the suspension liquid or the type of the suspension liquid changes. [Means for solving the problem]

[0017] The present invention has the following configuration for solving the above problems.

[0018] A spectroscopic measurement device for use by being attached to a pipe having a window through which a suspension liquid can be optically confirmed, the spectroscopic measurement device comprising: a light irradiating unit that irradiates light onto the suspension liquid in the pipe through the window, and a light receiving unit that receives light emitted from the suspension liquid as a result of the light being irradiated from the light irradiating unit onto the suspension liquid, the spectroscopic measurement device comprising a variable mechanism that can change at least one of the angle and irradiation position of the light irradiated onto the window from the light irradiating unit. Also, a method for adjusting the spectroscopic measurement device. Effect of the Invention

[0019] According to the present invention, it is possible to provide a spectroscopic measurement device and an optical system adjustment method that can be applied to production lines in various fields in which pipes of various shapes and materials are used.

[0020] It is also possible to provide a spectroscopic measurement device and an optical adjustment method that are applicable even when the size of the suspended particles in the suspension liquid or the type of the suspension liquid changes. [Brief description of the drawings]

[0021] [Figure 1A] 1 is a cross-sectional view taken perpendicular to the longitudinal direction of a pipe of a spectroscopic measuring device according to an embodiment of the present invention; [Figure 1B] FIG. 1 is a view showing a spectroscopic measuring device according to an embodiment of the present invention, viewed in a direction along the longitudinal direction of a pipe. [Diagram 2] FIG. 1 is a diagram showing a result measured when an optical system adjustment is performed using a spectroscopic measurement device. [Diagram 3] FIG. 1 is a diagram showing a result measured when an optical system adjustment is performed using a spectroscopic measurement device. [Figure 4] FIG. 1 is a diagram showing a result measured when an optical system adjustment is performed using a spectroscopic measurement device. [Diagram 5] FIG. 1 is a diagram showing a result measured when an optical system adjustment is performed using a spectroscopic measurement device. [Figure 6] Flowchart showing an example of optical system adjustment [Figure 7] Flowchart showing an example of optical system adjustment [Figure 8A] Conceptual diagram showing quantitative analysis using a calibration curve (measurement results using conventional technology) [Figure 8B] Conceptual diagram showing the quantitative method using a calibration curve (measurement results using the technology of the present invention) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description shows a specific example of the contents of the present invention, and the present invention is not limited to these descriptions. Various changes and modifications are possible by those skilled in the art within the scope of the technical ideas disclosed in this specification. In addition, in all the drawings for explaining the present invention, parts having the same functions are given the same reference numerals, and repeated explanations thereof may be omitted. EXAMPLES

[0023] Figures 1A and 1B are conceptual diagrams showing an example of a spectroscopic measurement device attached to a pipe having a window material. Figure 1A is a cross-sectional view cut in a direction perpendicular to the longitudinal direction of the pipe, and Figure 1B is a view along the longitudinal direction. Hereinafter, Figures 1A and 1B will be collectively referred to as Figure 1.

[0024] In FIG. 1, the spectroscopic measurement device includes a spectroscopic device 100 , a probe jig 120 , a measurement probe 141 , an irradiation optical fiber 142 , and a receiving optical fiber 143 , and is attached to a pipe 160 .

[0025] The spectroscopic device 100 is a double-beam spectrophotometer, and includes a light source 102, a spectroscope 103, and a detector 104, to which an irradiation optical fiber 142 and a receiving optical fiber 143 are connected.

[0026] The light emitted from the light source 102 is monochromatized by the spectroscope 103 and introduced into the irradiation optical fiber 142. The light from the irradiation optical fiber 142 is irradiated onto the suspension liquid 162 in the piping through the window material 161, and a part of the diffuse reflected light from the suspension liquid 162 enters the light receiving fiber 143 again through the window material 161. The light entering the light receiving fiber 143 includes not only the diffuse reflected light from the suspension liquid 162, but also light from the irradiation optical fiber 142 that is reflected or scattered on the surface of the window material. The reflection and scattering on the surface of the window material here occurs on both the outer surface (the side that the measurement probe approaches) and the inner surface (the side that comes into contact with the suspension liquid).

[0027] Furthermore, when the light from the irradiation optical fiber 142 and the light incident on the light receiving fiber 143 pass through the window material 161, they are attenuated due to light absorption by the window material.

[0028] The light incident on the light-receiving optical fiber 143 is detected by the detector 104 as measurement light. Although not shown, the light output from the spectroscope 103 is incident on the detector 104 without passing through the illumination optical fiber 142 and the receiving optical fiber 143, and serves as a so-called reference light.

[0029] The light source 102 is preferably a white light source having a continuous spectrum. An incandescent lamp, a halogen lamp, a xenon lamp, a white light emitting diode, a wavelength tunable laser, or the like can be used, but any other light source capable of emitting light of multiple wavelengths may also be used.

[0030] The spectroscope 103 is preferably a spectroscope using a diffraction grating, but may also be a spectroscope using a prism or an optical filter.

[0031] Detector 104 is preferably a photomultiplier tube or a photoconductive element such as PbS or CdS, but may also be a photodiode, PIN diode, pyrometer, or other light detector.

[0032] The spectroscopic device 100 can output, as measurements, the light energy measured by the detector 104, the reflectance, which is the ratio of the light energies measured for the measurement light and the reference light described above, and the absorbance, which is the common logarithm of the reciprocal of the reflectance.

[0033] The illumination optical fiber 142 and the receiving optical fiber 143 are bundled together by a measurement probe 141 attached to the other end of the spectrometer 100 .

[0034] The probe jig 120 includes a linear movement mechanism 121 , a rotational movement mechanism 122 , and a fixing portion 123 . A measurement probe 141 is fixed to the rotational movement mechanism 122 , and is fixed to a pipe 160 by the fixing portion 123 .

[0035] The linear movement mechanism 121 can use a linear movement stage.

[0036] The linear movement mechanism 121 is preferably installed so that the movement direction is generally perpendicular to the axial direction 163 of the pipe 160 .

[0037] The rotary movement mechanism 122 can use a rotary stage.

[0038] It is preferable that the direction of the rotation axis of the rotation movement mechanism 122 roughly coincides with the movement direction of the linear movement stage.

[0039] As the guide structure of the linear movement mechanism 121 and the rotational movement mechanism 122, for example, a dovetail groove system, a ball guide system, or a cross roller guide system can be appropriately used.

[0040] As a moving method for the linear movement mechanism 121 and the rotary movement mechanism 122, a manual method or an electric method using a rotary motor or a linear motor can be appropriately used.

[0041] The probe jig 120 and the fixing portion 123 may be made of, for example, a metal or a resin material.

[0042] However, when the suspension liquid 162 is at a high temperature, heat is transferred through the piping 160 and the resin material may be deformed, so metal is preferable, and stainless steel, iron or aluminum is most preferable.

[0043] The pipe 160 includes a cylindrical window material 161, a flange 164, and a fixed rod 165, and a suspension liquid 162 flows inside.

[0044] The window material 161 is sandwiched between flanges 164 on both sides. The flanges 164 on both sides are fixed by four fixing rods 165, whereby the window material 161 is fixed to the pipe 160.

[0045] The material of the window material 161 may be any light-transmitting material, such as glass, quartz, sapphire, or a transparent resin material.

[0046] The material of the pipe 160 (including the flange 164 and the fixed rod 165) other than the window material 161 may be, for example, a metal or a resin material as appropriate.

[0047] However, when the suspension liquid 162 is at a high temperature or flows under high pressure, the resin material may be deformed due to the high temperature, and therefore glass or reinforced glass is preferable as the material for the window material 161. For the same reason, the material for the pipe 160 other than the window material 161 (including the flange 164 and the fixed rod 165) is preferably a metal such as stainless steel or iron.

[0048] The monochromatic light introduced from the spectrometer 100 to the illumination optical fiber 142 is irradiated onto the window material 161 through the measurement probe 141. A part of the light is refracted and enters from the outer surface of the window material 161, and a further part of the light is refracted and enters the inside of the suspension liquid 162 from the inner surface of the window material 161.

[0049] A part of the light that has entered the suspension liquid 162 changes direction due to scattering by particles, molecules, etc. inside the suspension liquid 162, and a part of the light enters the window material 161 again from the inner surface of the window material 161 as refracted light, and further enters the atmosphere from the outer surface of the window material 161 as refracted light, and a part of the light enters the light-receiving optical fiber 143 bundled in the measurement probe 141. The intensity of the light that has entered the light-receiving optical fiber 143 is detected by the photodetector of the spectrometer 100.

[0050] The light incident on the light-receiving optical fiber 143 is absorbed by molecules and particles inside the suspension liquid 162 as it travels through the suspension liquid 162. Therefore, by measuring the light incident on the light-receiving optical fiber 143 with the spectrometer 100, the effect of light absorption by the components of the suspension liquid 162 can be investigated.

[0051] According to the above configuration, the measurement probe 141 is also connected to the linear movement mechanism 121 via the rotational movement mechanism 122, and the linear movement mechanism 121 is further connected to the pipe 160 via the probe jig 120 main body and the fixed portion 123. Therefore, the position of the measurement probe 141 with respect to the window material 161 can be changed using the linear movement mechanism 121. In addition, the angle of the measurement probe 141 with respect to the window material 161 can be changed using the rotational movement mechanism 122.

[0052] Since the position of the measurement probe 141 relative to the window material 161 can be adjusted, it is possible to perform highly accurate spectroscopic measurements by adjusting the measurement conditions to suppress detection of light reflected and scattered by the outer and inner surfaces of the window material 161 while also suppressing attenuation of light due to light absorption by the window material.

[0053] In the above embodiment 1, a case has been described in which a double-beam wavelength dispersive spectrophotometer is used as the spectroscopic device 100, but the type is not limited to the above, and for example, a single-beam wavelength dispersive spectrophotometer or a Fourier transform spectrophotometer may also be used.

[0054] The measured values ​​obtained by these spectrophotometers may be light energy, the number of photons, the output voltage or the output current of the detector, in addition to the light energy, reflectance, and absorbance mentioned above.

[0055] Furthermore, the spectroscopic device 100 is not limited to a spectrophotometer, and may be, for example, a fluorescence spectrophotometer. In this case, for example, the fluorescence intensity may be used as the measurement value.

[0056] A Raman spectrometer may also be used, in which case the Raman scattering intensity can be used as the measurement value.

[0057] In the above embodiment, the linear movement mechanism 121 and the rotational movement mechanism 122 are described as the movement mechanisms included in the probe jig 120, but the probe jig 120 may have movement mechanisms other than these two. EXAMPLES

[0058] An example of the optical system adjusting method of the present invention will now be described. The spectrometer used in this embodiment is the spectrometer in the above-described first embodiment, and measures the absorbance of the suspension liquid 162 flowing inside the pipe 160.

[0059] The suspension 162 was a liquid in which vegetable oil was dispersed in water using an emulsifier.

[0060] In this embodiment, a method of adjusting the position of the measurement probe 141, which can be adjusted by the linear movement mechanism 121, to a suitable position by measuring the reflectance will be described.

[0061] The order of steps is shown in Figure 6, and is specifically described below.

[0062] In the first step (a) 601, the measurement conditions of the spectroscopic device 100 are set as follows.

[0063] The reflectance is measured at 5 nm intervals under the conditions of a wavelength sweep range of 1700 nm to 1200 nm and a wavelength sweep speed of 1200 nm / min.

[0064] The above wavelength sweep range was selected because the light absorption band due to moisture in the suspension is observed around 1460 nm, and because measurements were also performed in the region outside of that wavelength band where there is no influence of light absorption due to moisture.

[0065] When quantifying components other than water in the suspension, a different wavelength range may be selected. For example, when quantifying the components of vegetable oils and fats, a wavelength range may be selected so that the light absorption band around a wavelength of 1200 nm can be measured.

[0066] In the next step (b) 602, the optical system state, that is, the position of the measurement probe 141 is moved using the linear movement mechanism 121. The movement position X is set to +3.5 mm.

[0067] In the next step (c) 603, the spectrometer 100 performs measurement under the conditions set in step (a) 601, and measures the reflectance from wavelengths 1700 nm to 1200 nm as a spectrum.

[0068] The bottom of FIG. 2 shows the measured reflectance spectrum at a translation position X of +3.5 mm.

[0069] The spectral shape is characterized by a decrease in reflectance around 1460 nm due to absorption by water in the suspension flowing inside the pipe.

[0070] In the next step (d) 604, the reflectance at a wavelength of 1280 nm from the spectrum obtained in step (c) 603 is obtained as a part of the evaluation value.

[0071] The reason for selecting the wavelength of 1280 nm is to avoid the influence of changes in the amount of moisture in the suspension in the pipe when selecting a wavelength near 1460 nm, where absorption by moisture in the suspension in the pipe occurs. Here, 1280 nm was selected, but another wavelength may be used as long as it is not influenced by absorption by moisture. For example, 1650 nm may be selected.

[0072] Next, steps (a) 601 to (c) 603 are repeated. At this time, the measurement conditions of step (a) 601 are set as described above, and the movement position X of step (b) 602 is moved in the negative direction by 0.5 mm for each repetition. Steps (a) 601 to (c) 603 are repeated until the movement position becomes -3.5 mm, and a pair of the movement position X and the corresponding reflectance is obtained as an evaluation value.

[0073] FIG. 2 shows the reflection spectra measured when the movement position X is 1.0 mm and 0 mm.

[0074] It can be seen that the reflection spectrum changes depending on the movement position X. The evaluation values ​​in the spectrum shown in Figure 2, that is, the pairs of movement position X and reflectance at a wavelength of 1280 nm, are (3.5 mm, 1.09%), (1.0 mm, 3.82%), and (0 mm, 5.77%).

[0075] Next, in step (e) 605, a suitable value is calculated from the evaluation values ​​obtained by repeating steps (a) 601 to (c) 603. Figure 3 shows the reflectance at a wavelength of 1280 nm versus movement position X. Within the range of movement position X (-3.5 to +3.5 mm), the reflectance is maximized when X is 0 mm, and this position is the suitable value.

[0076] In the next step (f) 606 , the optical system state, that is, the position of the measurement probe 141 is set to the preferred value (X=0 mm) obtained in step (e) 605 .

[0077] Through the series of steps up to this point, the state of the optical system, that is, the position of the measurement probe 141 in the X direction can be adjusted to a suitable state.

[0078] In the above-mentioned Example 2, the measurement value measured in step (c) 603 is reflectance, which is the ratio of the light energy measured for the measurement light and the reference light. However, it is also possible to use relative reflectance, i.e., the value obtained by dividing the light energy of the measurement light measured for the suspension liquid by the light energy of the measurement light measured in advance using a standard sample.

[0079] The light energy is generally called light intensity. The measured value may be another value, such as the number of photons, which is a value corresponding to the amount of light, or an output value from a detector, such as a voltage value or a current value. These values ​​may also be calculated using a previously measured reference value.

[0080] In the above-mentioned second embodiment, a spectrophotometer is used as the spectroscopic device 100, but the present invention is not limited to this. For example, a fluorescence spectrophotometer may be used.

[0081] In this case, for example, the optical energy of the excitation light can be used as the measured value. A Raman spectroscopic device may also be used, and in that case, the optical energy of the excitation light can also be used as the measured value. EXAMPLES

[0082] Another example of the optical system adjusting method of the present invention will be described below.

[0083] In this embodiment, a method for adjusting the position of the adjustable measuring probe 141 to a suitable position by the rotational movement mechanism 122 will be described.

[0084] The spectroscopic measurement device used in this adjustment method is the same as the spectroscopic measurement device, piping, and suspension liquid described in the above-mentioned Example 2, and the position of the measurement probe 141 in the X direction is adjusted to a suitable state (X = 0 mm) by the method of the above-mentioned Example 2.

[0085] The order of steps is shown in Figure 6, and is specifically described below.

[0086] In the first step (a) 601, the measurement conditions of the spectroscopic device 100 are set as follows.

[0087] The measurement is performed under the conditions of a wavelength sweep range of 1700 nm to 1200 nm, a wavelength sweep speed of 1200 nm / min, and absorbance measurement at 5 nm intervals.

[0088] The reason for selecting the above wavelength sweep range is the same as that described in the second embodiment.

[0089] In the next step (b) 602, the optical system state, that is, the position of the measurement probe 141 is moved using the rotational movement mechanism 122. The movement position θ is set to 0°.

[0090] In the next step (c) 603, the spectrometer 100 performs measurement under the conditions set in step (a) 601, and measures the absorbance from wavelengths 1700 nm to 1200 nm as a spectrum.

[0091] FIG. 4 shows an example of the absorbance spectrum measured when the movement position θ is 0°, 4°, and 10°.

[0092] It can be seen that the absorbance spectrum changes depending on the movement position θ. The peak seen near 1460 nm indicates the light absorption band due to the water in the suspension liquid 162.

[0093] In the next step (d) 604, the variation in absorbance near a wavelength of 1280 nm in the spectrum obtained in step (c) 603 is defined as a noise component, and the difference between the absorbance at 1460 nm and the absorbance at 1280 nm, i.e., the effective value of light absorption by the water in the suspension liquid 162, is defined as a signal component, and the S / N ratio of the absorbance obtained by the formula (signal component)÷(noise component) is obtained as part of the evaluation value.

[0094] However, the variation in absorbance is calculated as the difference between the maximum and minimum values ​​for a total of 11 absorbance data points, including the data for the wavelength of interest (1280 nm) and the five points before and after it. The reason why the variation in absorbance is calculated at a wavelength of 1280 nm is because this is a wavelength region in which the spectrum shape is flat. In areas where the spectrum shape is inclined or has a peak top shape, the maximum and minimum values ​​are affected.

[0095] Next, steps (a) 601 to (c) 603 are repeated. At this time, the measurement conditions of step (a) 601 are set as described above, and the movement position θ of step (b) 602 is moved in the positive direction by 2° for each repetition. Steps (a) 601 to (c) 603 are repeated until the movement position becomes 18°, and a pair of the movement position θ and the corresponding S / N ratio is obtained as an evaluation value.

[0096] The evaluation values ​​in the spectrum shown in FIG. 4, that is, pairs of the movement position θ and the S / N ratio calculated by the above method, are (0°, 10.2), (4°, 13.9), and (10°, 24.2).

[0097] Next, in step (e) 605, a suitable value is calculated from the combination of the evaluation value, i.e., the movement position θ and the corresponding S / N ratio of absorbance obtained in the above step. Figure 5 shows the S / N ratio of absorbance versus movement position θ. The S / N ratio is maximized when θ is 10°, and this position is the suitable value.

[0098] In the next step (f) 606 , the optical system state, that is, the position of the measurement probe 141 is set to the preferred value (θ=10 mm) obtained in step (e) 605 .

[0099] Through the series of steps up to this point, the state of the optical system, that is, the position of the measurement probe 141 can be adjusted to a suitable state.

[0100] By the adjustment described in this embodiment, the optical system can be adjusted to a more suitable state.

[0101] The reason for this is that by performing the optical system adjustment of the second embodiment, the rotation plane of the measurement probe adjusted by the rotation movement mechanism 122 in the third embodiment can be made to coincide with a plane including the central axis of the pipe 160.

[0102] If the rotation plane of the measurement probe 141 by the rotational movement mechanism 122 is offset from the central axis of the piping 160, the distance that the irradiated light from the measurement light passes through the window material 161 and the distance that the reflected light from the suspension liquid 162 toward the measurement probe 141 passes through the window material 161 become longer, and the measurement probe 141 is strongly affected by light absorption by the window material 161.

[0103] By making the plane of rotation of measurement probe 141 by rotation movement mechanism 122 coincide with a plane including the central axis of pipe 160, the effect of light absorption by window material 161 can be minimized.

[0104] If the suspension liquid 162 is a suspension liquid with known component concentrations and its absorbance is measured to create a calibration curve, it becomes possible to quantify the components in the suspension liquid 162 when the component concentrations are unknown. By carrying out the adjustments described in this example, the accuracy of absorbance measurement is improved, and therefore the accuracy of the calibration curve is improved.

[0105] This will be explained using the diagram. The open circles in Figure 8A show the results of measuring the absorbance of a sample containing multiple known components when the accuracy of the absorbance measurement is low (S / N ratio = 9), and the dotted line shows the calibration curve (coefficient of determination = 0.835) based on the measurement points.

[0106] The black dots and solid line in Figure 8B show the absorbance (S / N ratio = 25) and calibration curve (coefficient of determination = 0.996) of a sample with known components when the accuracy of absorbance measurement is improved by the method of the present invention or the like.

[0107] It can be seen that by adjusting the state of the optical system to a suitable state and improving the accuracy of absorbance measurement, the coefficient of determination of the calibration curve is improved, and the calibration accuracy is improved.

[0108] In this embodiment, after the X direction is adjusted to a suitable position by the method of embodiment 2, the θ direction is adjusted to a suitable position. However, the present invention can also be applied to a case where the spectroscopic measurement device does not have a mechanism for adjusting the position of the measurement probe in the X direction and the rotation plane in the θ direction roughly coincides with the central axis of the piping.

[0109] In this case, the shape of the window material 161 does not need to be cylindrical, and may be, for example, a plate-like shape. EXAMPLES

[0110] Another example of the optical system adjusting method of the present invention will be described below.

[0111] In this embodiment, a method for adjusting the position of the adjustable measurement probe 141 to a suitable position by the rotational movement mechanism 122, which is different from that in the third embodiment, will be described.

[0112] The spectroscopic measurement device used in this adjustment method is the same as the spectroscopic measurement device, piping, and suspension liquid described in the above-mentioned Example 2, and the position of the measurement probe 141 in the X direction is adjusted to a suitable state (X = 0 mm) by the method of the above-mentioned Example 2.

[0113] The order of steps is shown in FIG. 7, and is specifically described below.

[0114] In the first step (a) 701, the measurement conditions of the spectrometer 100 are set as follows.

[0115] The absorbance is measured at wavelengths of 1280 nm and 1460 nm for 5 seconds at 0.5 second intervals, i.e., 10 absorbance points are measured at each wavelength.

[0116] In the next step (b) 702, the optical system state, that is, the position of the measurement probe 141 is moved using the rotational movement mechanism 122. The movement position θ is set to 0°.

[0117] In the next step (c) 703, a plurality of data points of absorbance at a wavelength of 1280 nm and a plurality of data points of absorbance at a wavelength of 1460 nm are measured by the spectrometer 100. Here, the number of the plurality of data points is 10 as described above.

[0118] In the next step (d) 704, using the multiple data obtained in step (c) 703, the variation in absorbance near a wavelength of 1280 nm (the difference between the maximum and minimum values ​​for 10 data points) is taken as the noise component, and the difference between the average absorbance at 1460 nm and the average absorbance at 1280 nm is taken as the signal component, and the S / N ratio of the absorbance obtained by the formula (signal component)÷(noise component) is obtained as part of the evaluation value.

[0119] Next, in step (e) 705, if the evaluation value obtained in the above step is equal to or greater than the evaluation value obtained in advance, the movement position θ at that time is calculated as a suitable value.

[0120] If the optimum value cannot be calculated in step (e) 705, steps (a) 701 to (e) 705 are repeated. At this time, the measurement conditions in step (a) 701 are set as described above, and the movement position θ in step (b) 702 is moved in the positive direction by 2° for each repetition. Steps (a) 701 to (e) 705 are repeated until the movement position becomes 14°.

[0121] By performing the series of steps up to this point, the number of data items measured by repeating step (a) 701 to step (e) 705 can be reduced compared to the third embodiment, and the time required for adjustment can be shortened.

[0122] For example, when the probe jig 120 is removed from the pipe 160 and then reattached, the state of the optical system, that is, the position of the measurement probe 141, can be quickly adjusted to a suitable state.

[0123] The present invention is not limited to the above-mentioned embodiments, and includes various modified examples. For example, the above-mentioned embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the configurations described. In addition, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration. [Explanation of symbols]

[0124] 100 spectroscopic equipment 102 Light source 103 Spectrometer 104 Photodetector 120 Probe fixture 121 Linear movement mechanism 122 Rotational movement mechanism 123 Fixing part to pipe 141 Measuring Probe 142 Optical fiber for illumination 143 Receiving optical fiber 160 Piping 161 Window Materials 162 Suspension liquid 163 Pipe Axial Direction 164 Flange

Claims

1. A spectroscopic measuring device that is attached to a pipe having a window through which a suspension liquid can be optically confirmed, a light irradiation unit that irradiates light onto the suspension liquid in the piping through the window; a light receiving unit for receiving light emitted from the suspension liquid when the suspension liquid is irradiated with light from the light irradiating unit; A spectroscopic device comprising: A spectroscopic measuring device comprising: a variable mechanism capable of changing at least one of an angle and an irradiation position of light irradiated from said light irradiating portion to said window portion.

2. 2. The spectroscopic measurement device according to claim 1, A spectroscopic measurement device characterized in that the arrangements of the light irradiating unit and the light receiving unit are fixed, and the variable mechanism is a mechanism that changes both the light irradiating unit and the light receiving unit while maintaining their positional relationship.

3. 2. The spectroscopic measurement device according to claim 1, a light receiving section for receiving light from the light emitting section and the light receiving section for receiving light from the light receiving section;

4. 2. The spectroscopic measurement device according to claim 1, The spectroscopic measurement device according to claim 1, wherein the variable mechanism is a mechanism for varying an irradiation position of light irradiated from the light irradiation unit to the window unit in a direction different from an axial direction of the pipe.

5. A method for adjusting a spectroscopic measurement device according to any one of claims 1 to 4, comprising: acquiring a measurement value by changing at least one of an angle and an irradiation position of the light irradiated from the light irradiating unit to the window unit by the variable mechanism; A method for adjusting a spectroscopic measurement device, comprising determining the most suitable light angle and irradiation position based on the measured values.

6. 6. The method for adjusting a spectroscopic measurement device according to claim 5, The method for adjusting a spectrometer further comprises changing the wavelength of the light irradiated from the light irradiating unit to obtain optimal measurement conditions.

7. 6. The method for adjusting a spectroscopic measurement device according to claim 5, The measurement value is At least one of the light energy, the number of photons, the output value, the reflectance, and the absorbance measured by the light receiving unit; 13. A method for adjusting a spectroscopic measurement device, comprising:

8. The method for adjusting a spectroscopic measurement device according to claim 7, A method for adjusting a spectrometer, comprising determining optimal measurement conditions based on at least one of the light energy, the number of photons, the output value, the reflectance, and the absorbance.

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