Spectroscopic measurement reference instrument

Abstract

To provide a reference device for spectroscopic measurement that is capable of acquiring a predetermined quantitative value related to a measurement object with high accuracy.SOLUTION: A reference device 1A for spectroscopic measurement is used for a spectroscopic measurement device 10 comprising a head part 12 that emits irradiation light with which an object is irradiated and allows measurement light generated at the object in response to the irradiation of the irradiation light to be incident thereon. The reference device 1A for spectroscopic measurement comprises: a holding part 2 having a first opening 21 and a second opening 22 at which the head part 12 is arranged; an absorption part 3 that is arranged in a first region R1 set so as to face the first opening 21 and a second region R2 set so as to face the second opening 22, and has absorption properties for light in a predetermined wavelength range included in the irradiation light; and an adjustment part 4 that makes a presence state of the absorption part 3 in the first region R1 and a presence state of the absorption part 3 in the second region R2 different from each other.SELECTED DRAWING: Figure 12

Description

Technical Field

[0001] The present invention relates to a reference instrument for spectroscopic measurement used in a spectroscopic measurement apparatus.

Background Art

[0002] There is known a spectroscopic measurement apparatus including a head unit that emits irradiation light irradiated onto an object and into which measurement light generated in the object in response to the irradiation of the irradiation light is incident (see, for example, Patent Document 1). Such a spectroscopic measurement apparatus utilizes the property that a measurement target contained in the object (for example, fat contained in meat) is likely to absorb light in a specific wavelength band, and is used to obtain a predetermined quantitative value (for example, fat content, fat percentage, etc.) regarding the measurement target.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the spectroscopic measurement apparatus as described above, in an arithmetic expression for calculating a predetermined quantitative value based on the spectral data of the measurement light, obtaining an arithmetic coefficient or calibrating the arithmetic coefficient is important for accurately obtaining the predetermined quantitative value.

[0005] An object of the present invention is to provide a reference instrument for spectroscopic measurement that enables accurate acquisition of a predetermined quantitative value regarding a measurement target.

Means for Solving the Problems

[0006] The spectroscopic measurement reference instrument of the present invention is [1] "a spectroscopic measurement reference instrument used in a spectroscopic measuring device that includes a head portion that emits irradiation light to be irradiated onto an object and into which measurement light generated in the object in response to the irradiation of the irradiation light is incident, comprising: a holding portion having a first aperture and a second aperture on which the head portion is arranged; an absorbing portion arranged in a first region set to face the first aperture and a second region set to face the second aperture, and having absorbing properties for light in a predetermined wavelength band included in the irradiation light; and an adjustment portion that makes the presence state of the absorbing portion in the first region and the presence state of the absorbing portion in the second region different from each other."

[0007] In the spectroscopic measurement reference instrument described in [1] above, the absorbing part absorbs light in a predetermined wavelength band contained in the irradiated light, and the state of the absorbing part in the first region and the state of the absorbing part in the second region are different from each other. As a result, the first region can be defined as a region corresponding to "an object having a quantitative value of a first predetermined value," and the second region can be defined as a region corresponding to "an object having a quantitative value of a second predetermined value different from the first predetermined value." Therefore, by placing the head of the spectroscopic measurement device in each of the first and second apertures, and irradiating each of the first and second regions with irradiated light, the measurement light generated in each of the first and second regions can be spectrally analyzed and detected, making it possible to obtain calculation coefficients or calibrate calculation coefficients in the calculation formula for calculating a predetermined quantitative value based on the spectral data of the measurement light. Thus, the spectroscopic measurement reference instrument described in [1] above enables highly accurate acquisition of a predetermined quantitative value related to the object to be measured.

[0008] The spectroscopic measurement reference instrument of the present invention may also be [2] "the spectroscopic measurement reference instrument described in [1] above, wherein the adjustment section includes a first adjustment layer arranged along the first aperture in the first region, and a second adjustment layer arranged along the second aperture in the second region and having a different thickness from the first adjustment layer, and the absorption section is arranged in the region of the first region where the first adjustment layer is not arranged and in the region of the second region where the second adjustment layer is not arranged." According to the spectroscopic measurement reference instrument described in [2], the state of the presence of the absorption section in the first region and the second region can be adjusted with a simple configuration.

[0009] The spectroscopic measurement reference instrument of the present invention may also be [3] "the spectroscopic measurement reference instrument described in [2] above, wherein the first adjustment layer and the second adjustment layer are transparent to light in the predetermined wavelength band." According to the spectroscopic measurement reference instrument described in [3], it is possible to prevent the first adjustment layer and the second adjustment layer from affecting the characteristics of the irradiated light.

[0010] The spectroscopic measurement reference instrument of the present invention may also be [4] "the spectroscopic measurement reference instrument according to any one of [1] to [3] above, wherein the first aperture and the second aperture are opened on opposite sides to the absorption portion, and a part of the first region and a part of the second region overlap each other." According to the spectroscopic measurement reference instrument according to [4], the absorption portion is common in the region where a part of the first region and a part of the second region overlap each other, so that under similar conditions, the measurement light generated in the first region and the second region can be spectrally analyzed and detected.

[0011] The spectroscopic measurement reference instrument of the present invention may also be [5] "the spectroscopic measurement reference instrument according to any one of [1] to [3] above, wherein the first aperture and the second aperture are opened to the same side with respect to the absorption portion." According to the spectroscopic measurement reference instrument according to [5], the head portion of the spectroscopic measurement device can be positioned at the first aperture and the second aperture from the same side, making it possible to perform measurements by the spectroscopic measurement device efficiently.

[0012] The spectroscopic measurement reference instrument of the present invention may also be [6] "the spectroscopic measurement reference instrument according to any one of [1] to [5] above, wherein the holding part is a housing that houses the absorption part and the adjustment part." According to the spectroscopic measurement reference instrument according to [6], deterioration of the absorption part can be suppressed.

[0013] The spectroscopic measurement reference instrument of the present invention may also be [7] "the spectroscopic measurement reference instrument according to any one of [1] to [6] above, further comprising spacers arranged in the first aperture and the second aperture according to the size of the head portion." According to the spectroscopic measurement reference instrument according to [7], even if the size of the head portion is changed in the spectroscopic measurement device, the positioning of the head portion can be appropriately performed with respect to the first region and the second region, respectively. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a spectroscopic measurement reference instrument that enables highly accurate acquisition of predetermined quantitative values ​​related to the object to be measured. [Brief explanation of the drawing]

[0015] [Figure 1] This is a side view of a spectroscopic measurement device according to one embodiment. [Figure 2] Figure 1 is a front view of the spectroscopic measurement device. [Figure 3] This is a diagram showing the spectrum of the measured light. [Figure 4] This diagram shows the steps involved in determining the spectrum of the irradiated light. [Figure 5] This diagram shows the steps involved in determining the spectrum of the irradiated light. [Figure 6] This is a diagram showing the spectrum of the irradiated light. [Figure 7] This figure shows the second derivative of the spectrum of the measured light. [Figure 8] This figure shows an example of the display on the display unit of the arithmetic unit shown in Figure 1. [Figure 9]It is a diagram showing a display example in the display unit of the arithmetic unit shown in FIG. 1. [Figure 10] It is a perspective view of the spectrometer standard of the first embodiment. [Figure 11] It is a cross-sectional view of the spectrometer standard shown in FIG. 10. [Figure 12] It is a diagram showing an example of use of the spectrometer standard shown in FIG. 10. [Figure 13] It is a perspective view of the spectrometer standard provided with a spacer. [Figure 14] It is a perspective view of the spectrometer standard of the second embodiment. [Figure 15] It is a diagram showing an example of use of the spectrometer standard shown in FIG. 14. [Figure 16] It is a perspective view of the spectrometer standard of the second embodiment. [Figure 17] It is a perspective view of the adjustment part of the modification example. [Figure 18] It is a perspective view of the adjustment part of the modification example.

Modes for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant descriptions are omitted. [Configuration of Spectrometer]

[0017] The spectroscopic measurement device 10 shown in Figure 1 is a device that irradiates an object S with light and detects the measurement light (e.g., reflected light, scattered light, etc.) generated in the object S in response to the irradiation of the light by spectral analysis. The spectroscopic measurement device 10 utilizes the property that the measurement target contained in the object S (e.g., fat contained in meat) easily absorbs light in a specific wavelength band, and outputs the detection signal of the measurement light to an external computing device 100 in order to obtain a predetermined quantitative value (e.g., fat amount, fat percentage, etc.) related to the measurement target. The computing device 100 calculates the predetermined quantitative value based on the detection signal of the measurement light. The computing device 100 is a computer device comprising a main unit 101, a display unit 102 such as a display, and an input unit 103 such as a keyboard and mouse. The main unit 101 is a computing unit composed of a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc.

[0018] As shown in Figures 1 and 2, the spectroscopic measuring device 10 comprises a main body 11, a head 12, a cable 13, a plurality of light sources 14, and a spectrometer 15. The main body 11 includes a control unit (not shown) that controls each part of the spectroscopic measuring device 10. This control unit is electrically connected to the main body 101 of the computing device 100 by the cable 13. The main body 11 also functions as a grip for the operator.

[0019] The head portion 12 emits illumination light that is irradiated onto the object S, and is also the portion into which measurement light generated in the object S in response to the illumination light is incident. As shown in Figure 2, the head portion 12 has a cylindrical main body member 121, a plate-shaped holding member 122, a tubular light guide member 123, and a plate-shaped light transmitting member 124. The holding member 122 is attached to the inside of the main body member 121. The light guide member 123 is fixed to the holding member 122, passing through the central part of the holding member 122. The light transmitting member 124 is attached to the opening of the main body member 121 on the side opposite to the main body portion 11 (see Figure 1).

[0020] Multiple light sources 14 are attached to the head portion 12 via a wiring board (not shown) while being arranged in multiple openings formed in the holding member 122. The multiple light sources 14 are arranged to surround the light guide member 123. Each light source 14 is, for example, an LED (light emitting diode). As an example, if the object to be measured is fat, the multiple light sources 14 include a light source that emits light having a central wavelength in the 920-940 nm wavelength band, which is easily absorbed by fat, and a light source that emits light having a central wavelength in a wavelength band shorter than that specific wavelength band. In the spectroscopic measurement device 10, irradiation light is generated by the light emitted from the multiple light sources 14, and this irradiation light is irradiated onto the object S via the light transmitting member 124.

[0021] The spectrometer 15 is attached to the main body 11, facing the light guide member 123. The spectrometer 15 detects the measurement light that is incident on the light guide member 123 via the light transmitting member 124 and guided by the light guide member 123 by spectral analysis. As an example, the spectrometer 15 has a housing with a light incident section into which the measurement light is incident, a diffraction grating that spectrally analyzes the incident measurement light within the housing, and a photodetector element that detects the spectrally analyzed measurement light within the housing.

[0022] In the spectroscopic measuring device 10, the opening portion of the main body member 121 on the main body 11 (see Figure 1) side is detachably connected to the main body 11. This allows the unit composed of the head 12 and multiple light sources 14 to be detachably attached to the main body 11. Therefore, in the spectroscopic measuring device 10, the unit composed of the head 12 and multiple light sources 14 can be replaced with a different type of unit. The need to replace the unit composed of the head 12 and multiple light sources 14 arises because the "spectrum of the irradiated light" and the "positional relationship between the light guide member 123 and each light source 14" suitable for measurement vary depending on the measurement target and measurement location. Alternatively, in the spectroscopic measuring device 10, the spectrometer 15 may be attached to the head 12, and the unit composed of the head 12, multiple light sources 14, and spectrometer 15 may be detachably attached to the main body 11. [Method for determining the spectrum of the irradiated light]

[0023] The method for determining the spectrum of the irradiated light will be explained using the case where the object to be measured is fat as an example. For example, if multiple objects S with different fat percentages are prepared and light emitted from a general halogen lamp is used as the irradiated light for each object S, the spectrum of the measurement light will be acquired for each fat percentage in a wide wavelength range of 550 to 1100 nm, as shown in Figure 3. Here, in each spectrum shown in Figure 3, a significant change in the profile is evident in the narrow wavelength range W that includes the 920 to 940 nm wavelength band, which is easily absorbed by fat.

[0024] First, as shown in Figure 4(a), each spectrum is extracted within the wavelength range including wavelength range W. In wavelength range W, the higher the fat percentage, the more the spectral profile becomes "convex downwards". Therefore, as shown in Figures 4(a) and (b), an average spectrum BP is generated based on each spectrum when the fat percentage exceeds, for example, 80%. Subsequently, as shown in Figure 5(a), an inverse waveform pattern IP is generated by subtracting the average spectrum BP from a predetermined intensity value, for example. Then, as shown in Figure 5(b), the spectrum SP1 of the irradiated light having a profile approximated by the inverse waveform pattern IP is generated.

[0025] In other words, within a wavelength range that includes wavelength bands easily absorbed by the object S contained within the object S, the spectra of the measurement light are acquired for each quantitative value for multiple objects S with different predetermined quantitative values. Based on the spectra of each object in that wavelength range where the quantitative value exceeds the predetermined value, an average spectrum BP is generated. Based on the average spectrum BP, a spectrum SP1 of the irradiated light having a profile convex on the opposite side of the average spectrum BP is generated. This narrows the dispersion range of the intensity value of the detection signal of the measurement light, and allows the dynamic range of the photodetector element that detects the measurement light in the spectroscopic measurement device 10 to be allocated to this dispersion range, thereby improving the S / N ratio and resolution in the detection of the measurement light.

[0026] Figure 6 shows the spectrum of the irradiated light. As shown in Figure 6, the spectrum SP0 of light emitted from a typical halogen lamp has a peak at wavelengths shorter than the wavelength range W which includes the 920-940 nm wavelength band that fat easily absorbs, and extends over a wide wavelength range of 490-1100 nm. In contrast, the spectrum SP1 of the irradiated light determined by the method described above has a peak at wavelengths included in the 920-940 nm wavelength band that fat easily absorbs, and changes more sharply on the longer wavelength side of the wavelength range W than on the shorter wavelength side of the wavelength range W. [Method for calculating predetermined quantitative values ​​related to the object to be measured]

[0027] Using the example of a measurement target being fat, a method for calculating predetermined quantitative values ​​related to the measurement target will be explained. When the calculation device 100 acquires the detection signal of the measurement light from the spectroscopic measurement device 10, it performs a second derivative with respect to wavelength on the spectral data of the measurement light based on the detection signal. Figure 7 shows the second derivative values ​​of the spectrum of the measurement light. Figure 7 shows the second derivative value R1 calculated for an object S with a relatively small amount of fat, the second derivative value R3 calculated for an object S with a relatively large amount of fat, and the second derivative value R2 calculated for an object S with an intermediate amount of fat. Thus, in the wavelength range of 830 to 950 nm, the second derivative value changes significantly depending on the amount of fat.

[0028] The calculation device 100 determines the representative value x1 of the second derivative of the wavelength band Δλ1 including 850 nm, the representative value x2 of the second derivative of the wavelength band Δλ2 including 920 nm, and the representative value x3 of the second derivative of the wavelength band Δλ3 including 950 nm, and calculates quantitative values ​​related to fat (fat amount, fat percentage, etc.) using the calculation formula: f(x) = a·x1 + b·x2 + c·x3 + d. Here, a, b, c, and d in the above calculation formula are calculation coefficients that have been calculated in advance by regression calculation and stored in the calculation device 100. Note that each representative value x1, x2, and x3 may be the average, maximum, minimum, or center value of the second derivative in each wavelength band Δλ1, Δλ2, and Δλ3.

[0029] The calculation coefficients a, b, c, and d stored in the arithmetic unit 100 are obtained as follows: First, the amount of fat in the object S is obtained by chemical analysis such as the Soxhlet method. Next, the object S is measured by the spectroscopic measuring device 10, and the second derivative of the spectrum of the measured light is calculated. Subsequently, the calculation coefficients a, b, c, and d are obtained by performing a regression analysis in the arithmetic unit 100 using the fat amount data and the second derivative data obtained by chemical analysis. The regression analysis is performed by correlating the fat amount data and the second derivative data obtained by chemical analysis using methods such as multiple regression analysis and PLS analysis.

[0030] When the calculation unit 100 calculates quantitative values ​​related to fat (fat amount, fat percentage, etc.), it displays the calculation results on the display unit 102, as shown in Figures 8 and 9. In the example shown in Figure 8, "Fat amount per unit volume: 111.3 mg / cm³" 3 " and "Class: A" are displayed. In the example shown in Figure 9, the second derivative of the spectrum of the measured light is displayed. The display can be switched by clicking "Disp" via the input unit 103. [Spectroscopic measurement reference instrument of the first embodiment]

[0031] The spectroscopic measurement reference instrument 1A shown in Figures 10 and 11 is a reference instrument used in the spectroscopic measurement device 10 to calibrate the calculation coefficients a, b, c, and d in the above calculation formula. The spectroscopic measurement reference instrument 1A comprises a holding section 2, an absorption section 3, and an adjustment section 4. Hereinafter, the direction in which the first aperture 21, which will be described later, is open will be referred to as the Z direction.

[0032] As shown in Figures 10 and 11, the holding part 2 houses the absorption part 3 and the adjustment part 4. The holding part 2 is a light-shielding housing. The holding part 2 has a first opening 21 and a second opening 22. The first opening 21 and the second opening 22 face each other in the Z direction and open to opposite sides of the absorption part 3. More specifically, the holding part 2 has a plate-shaped first wall portion 23, a plate-shaped second wall portion 24, and a cylindrical third wall portion 25. The first wall portion 23 is attached to the opening portion of the third wall portion 25 on one side in the Z direction. The second wall portion 24 is attached to the opening portion of the third wall portion 25 on the other side in the Z direction. The first opening 21 is formed in the first wall portion 23. The second opening 22 is formed in the second wall portion 24. When viewed from the Z direction, the first opening 21 and the second opening 22 have the same shape as each other. The head portion 12 of the spectroscopic measuring device 10 is positioned in each of the first aperture 21 and the second aperture 22. Each of the first aperture 21 and the second aperture 22 has a function for positioning the head portion 12.

[0033] A first region R1 is set on one side of the first opening 21 in the Z direction (inside the housing, which is the holding part 2). In other words, the first region R1 is set to face the first opening 21. A second region R2 is set on the other side of the second opening 22 in the Z direction (inside the housing, which is the holding part 2). In other words, the second region R2 is set to face the second opening 22. The first region R1 and the second region R2 have the same shape. The part of the first region R1 opposite to the first opening 21 and the part of the second region R2 opposite to the second opening 22 overlap each other. In other words, a part of the first region R1 and a part of the second region R2 overlap each other.

[0034] The absorption section 3 is located in the first region R1 and the second region R2. The absorption section 3 has the ability to absorb light in a predetermined wavelength band contained in the irradiation light emitted from the spectroscopic measuring device 10. This predetermined wavelength band is a wavelength band that is easily absorbed by the object to be measured contained in the object S. For example, if the object to be measured is fat, the predetermined wavelength band is the 920-940 nm wavelength band, which is easily absorbed by fat. In that case, the material of the absorption section 3 is, for example, solid hardened oil.

[0035] The adjustment unit 4 makes the state of existence of the absorption unit 3 in the first region R1 and the state of existence of the absorption unit 3 in the second region R2 different from each other. The state of existence of the absorption unit 3 in the first region R1 refers to the state of the position of the absorption unit 3 in the first region R1 (position relative to the first opening 21), the state of the shape of the absorption unit 3 in the first region R1, the state of the proportion of the absorption unit 3 to the first region R1, etc. Similarly, the state of existence of the absorption unit 3 in the second region R2 refers to the state of the position of the absorption unit 3 in the second region R2 (position relative to the second opening 22), the state of the shape of the absorption unit 3 in the second region R2, the state of the proportion of the absorption unit 3 to the second region R2, etc.

[0036] In the spectroscopic measurement reference instrument 1A, the adjustment section 4 includes a first adjustment layer 41 and a second adjustment layer 42 having a different thickness from the first adjustment layer 41. The first adjustment layer 41 and the second adjustment layer 42 are transparent to light in a predetermined wavelength band included in the irradiation light emitted from the spectroscopic measurement device 10. The fact that the first adjustment layer 41 is transparent to light in a predetermined wavelength band means that when the light passes through the first adjustment layer 41, even if the thickness of the first adjustment layer 41 changes, the intensity profile of the light emitted from the first adjustment layer 41 is substantially the same as the intensity profile of the light incident on the first adjustment layer 41. Similarly, the fact that the second adjustment layer 42 is transparent to light in a predetermined wavelength band means that when the light passes through the second adjustment layer 42, even if the thickness of the second adjustment layer 42 changes, the intensity profile of the light emitted from the second adjustment layer 42 is substantially the same as the intensity profile of the light incident on the second adjustment layer 42. For example, if the object to be measured is fat, the materials of the first adjustment layer 41 and the second adjustment layer 42 are, for example, Teflon®.

[0037] The first adjustment layer 41 is positioned along the first aperture 21 in the first region R1. In other words, the first adjustment layer 41 is positioned to cover the first aperture 21 in the first region R1. The side surface 21a of the first aperture 21 and the surface 41a of the first adjustment layer 41 exposed within the first aperture 21 define the space in which the head portion 12 of the spectroscopic measuring device 10 is positioned. The second adjustment layer 42 is positioned along the second aperture 22 in the second region R2. In other words, the second adjustment layer 42 is positioned to cover the second aperture 22 in the second region R2. The side surface 22a of the second aperture 22 and the surface 42a of the second adjustment layer 42 exposed within the second aperture 22 define the space in which the head portion 12 of the spectroscopic measuring device 10 is positioned.

[0038] In the spectroscopic measurement reference instrument 1A, the thickness of the first adjustment layer 41 is greater than the thickness of the second adjustment layer 42, and the absorption section 3 is located in the region of the first region R1 where the first adjustment layer 41 is not located and in the region of the second region R2 where the second adjustment layer 42 is not located. As a result, the distance between the first aperture 21 and the absorption section 3 is greater than the distance between the second aperture 22 and the absorption section 3, the thickness of the absorption section 3 in the first region R1 is less than the thickness of the absorption section 3 in the second region R2, and the proportion of the absorption section 3 in the first region R1 is less than the proportion of the absorption section 3 in the second region R2. For example, if the object to be measured is fat, the first region R1 corresponds to an object S having a fat percentage of a first predetermined value, and the second region R2 corresponds to an object S having a fat percentage of a second predetermined value that is higher than the first predetermined value.

[0039] The spectroscopic measurement reference instrument 1A, configured as described above, is used as follows. First, as shown in Figure 12(a), the head portion 12 of the spectroscopic measurement device 10 is positioned in the first aperture 21. More specifically, the head portion 12 is positioned in the first aperture 21 such that the end face 12a of the head portion 12 is in contact with the surface 41a of the first adjustment layer 41, and the side surface 12b of the head portion 12 is in contact with the side surface 21a of the first aperture 21. The end face 12a of the head portion 12 is the surface of the head portion 12 from which the irradiation light is emitted and into which the measurement light is incident. With the head portion 12 positioned in the first aperture 21, the spectroscopic measurement device 10 irradiates the first region R1 with irradiation light, spectrally analyzes and detects the measurement light generated in the first region R1, and outputs the detection signal of the measurement light to the computing device 100.

[0040] Next, as shown in Figure 12(b), the head portion 12 of the spectroscopic measuring device 10 is positioned in the second aperture 22. More specifically, the head portion 12 is positioned in the second aperture 22 such that the end face 12a of the head portion 12 is in contact with the surface 42a of the second adjustment layer 42 and the side surface 12b of the head portion 12 is in contact with the side surface 22a of the second aperture 22. With the head portion 12 positioned in the second aperture 22, the spectroscopic measuring device 10 irradiates the second region R2 with illumination light, spectrally analyzes and detects the measurement light generated in the second region R2, and outputs the detection signal of the measurement light to the computing device 100.

[0041] The calculation unit 100 stores data relating to the quantitative values ​​of the first region R1 and the second region R2, respectively. The data relating to the quantitative values ​​of the first region R1 is data indicating that the first region R1 corresponds to an object S having a quantitative value of a first predetermined value. The data relating to the quantitative values ​​of the second region R2 is data indicating that the second region R2 corresponds to an object S having a quantitative value of a second predetermined value that is higher than the first predetermined value. Based on the stored data relating to the quantitative values ​​of the first region R1 and the second region R2, as well as the detection signals of the measurement light of the first region R1 and the second region R2, respectively, the calculation unit 100 calibrates the calculation coefficients a, b, c, and d in the calculation formula described above.

[0042] As described above, in the spectroscopic measuring device 10, the unit composed of the head unit 12 and the multiple light sources 14 can be replaced with a different type of unit. Therefore, the spectroscopic measuring reference instrument 1 may further include spacers 5 that are placed in the first aperture 21 and the second aperture 22, respectively, according to the size of the head unit 12, as shown in Figure 13. The spacer 5 has a ring-shaped main body 51 that fits into the first aperture 21 and the second aperture 22, respectively. When the spacer 5 is placed in the first aperture 21, the head unit 12 is positioned in the first aperture 21 such that the end face 12a of the head unit 12 is in contact with the surface 41a of the first adjustment layer 41 and the side surface 12b of the head unit 12 is in contact with the side surface 51a of the main body 51. Similarly, when the spacer 5 is positioned in the second opening 22, the head portion 12 is positioned in the second opening 22 such that the end face 12a of the head portion 12 is in contact with the surface 42a of the second adjustment layer 42 and the side surface 12b of the head portion 12 is in contact with the side surface 51a of the main body portion 51.

[0043] As explained above, in the spectroscopic measurement reference instrument 1A, the absorption section 3 absorbs light in a predetermined wavelength band contained in the irradiated light, and the state of the absorption section 3 in the first region R1 and the state of the absorption section 3 in the second region R2 are different from each other. As a result, the first region R1 can be designated as a region corresponding to "an object S having a quantitative value of a first predetermined value," and the second region R2 can be designated as a region corresponding to "an object S having a quantitative value of a second predetermined value different from the first predetermined value." Therefore, by placing the head section 12 of the spectroscopic measurement device 10 in the first aperture 21 and the second aperture 22, and irradiating the first region R1 and the second region R2 with irradiated light, the measurement light generated in the first region R1 and the second region R2 can be spectrally analyzed and detected, making it possible to obtain calculation coefficients and calibrate calculation coefficients in the calculation formula for calculating a predetermined quantitative value based on the spectral data of the measurement light. Thus, the spectroscopic measurement reference instrument 1A enables highly accurate acquisition of a predetermined quantitative value related to the measurement target.

[0044] In the spectroscopic measurement reference instrument 1A, the adjustment section 4 includes a first adjustment layer 41 arranged along the first aperture 21 in the first region R1, and a second adjustment layer 42 arranged along the second aperture 22 in the second region R2 and having a different thickness from the first adjustment layer 41. The absorption section 3 is arranged in the region of the first region R1 where the first adjustment layer 41 is not arranged and in the region of the second region R2 where the second adjustment layer 42 is not arranged. This allows the presence of the absorption section 3 in the first region R1 and the second region R2 to be adjusted with a simple configuration.

[0045] In the spectroscopic measurement reference instrument 1A, the first adjustment layer 41 and the second adjustment layer 42 are transparent to light in a predetermined wavelength band. This prevents the first adjustment layer 41 and the second adjustment layer 42 from affecting the characteristics of the irradiated light.

[0046] In the spectroscopic measurement reference instrument 1A, the first aperture 21 and the second aperture 22 open on opposite sides of the absorption section 3, and a portion of the first region R1 and a portion of the second region R2 overlap with each other. As a result, the absorption section 3 is common in the region where a portion of the first region R1 and a portion of the second region R2 overlap, making it possible to spectrally analyze and detect the measurement light generated in the first region R1 and the second region R2 under similar conditions.

[0047] In the spectroscopic measurement reference instrument 1A, the holding unit 2 is a housing that contains the absorption unit 3 and the adjustment unit 4. This makes it possible to suppress the deterioration of the absorption unit 3.

[0048] In the spectroscopic measurement reference instrument 1A, spacers 5 are placed in the first aperture 21 and the second aperture 22, respectively, according to the size of the head portion 12. This allows for appropriate positioning of the head portion 12 in the first region R1 and the second region R2, respectively, even when the size of the head portion 12 is changed in the spectroscopic measurement device 10. [Spectroscopic measurement reference instrument of the second embodiment]

[0049] The spectroscopic measurement reference instrument 1B shown in Figures 14 and 15 differs from the spectroscopic measurement reference instrument 1A described above in that the first aperture 21 and the second aperture 22 are opened on the same side. Below, the configuration of the spectroscopic measurement reference instrument 1B that differs from the configuration of the spectroscopic measurement reference instrument 1A will be described, and the configuration of the spectroscopic measurement reference instrument 1B that is the same as the configuration of the spectroscopic measurement reference instrument 1A will not be described.

[0050] As shown in Figures 14 and 15, the first aperture 21 and the second aperture 22 are aligned in one direction perpendicular to the Z direction and open to the same side of the absorption section 3. In the spectroscopic measurement reference instrument 1B, the first aperture 21 and the second aperture 22 are formed in the first wall section 23 of the holding section 2, and the first adjustment layer 41 and the second adjustment layer 42 are arranged between the absorption section 3 and the first wall section 23. A first holding member 26, which is part of the holding section 2, is arranged between the second adjustment layer 42 and the first wall section 23. A second holding member 27, which is part of the holding section 2, is arranged between the first adjustment layer 41 and the second adjustment layer 42, and between the first adjustment layer 41 and the first holding member 26. In the spectroscopic measurement reference instrument 1B, the second aperture 22 is defined by the first wall section 23 and the first holding member 26. Furthermore, a light-shielding cover (not shown) may be placed in the opening to which the spectroscopic measuring device 10 is not fitted (the second opening 22 in the state shown in Figure 15) to block ambient light.

[0051] With the spectroscopic measurement reference instrument 1B configured as described above, it is possible to obtain predetermined quantitative values ​​related to the object to be measured with high accuracy, similar to the spectroscopic measurement reference instrument 1A.

[0052] In the spectroscopic measurement reference instrument 1B, the first aperture 21 and the second aperture 22 open to the same side relative to the absorption section 3. This allows the head portion 12 of the spectroscopic measurement device 10 to be positioned at the first aperture 21 and the second aperture 22 from the same side, thereby enabling efficient measurement by the spectroscopic measurement device 10. [Spectroscopic measurement reference instrument of the third embodiment]

[0053] The spectroscopic measurement reference instrument 1C shown in Figure 16 differs from the spectroscopic measurement reference instrument 1A described above in that the first aperture 21 and the second aperture 22 open to the same side, and differs from the spectroscopic measurement reference instrument 1B described above in that the light-shielding second holding member 27 extends from the first wall portion 23 to the second wall portion 24. Below, the configuration of the spectroscopic measurement reference instrument 1C that differs from the configurations of the spectroscopic measurement reference instrument 1A and the spectroscopic measurement reference instrument 1B will be described, and the configuration of the spectroscopic measurement reference instrument 1C that is the same as the configurations of the spectroscopic measurement reference instrument 1A and the spectroscopic measurement reference instrument 1B will not be described.

[0054] As shown in Figure 16, in the spectroscopic measurement reference instrument 1C, the second holding member 27, which is part of the holding portion 2, extends from the first wall portion 23 to the second wall portion 24, separating the absorption portion 3 into the first absorption portion 3a and the second absorption portion 3b. The second holding member 27 has light-shielding properties and functions as a light-shielding member. In the spectroscopic measurement reference instrument 1C, the second aperture 22 is defined by the first wall portion 23, similar to the first aperture 21. Therefore, the surface of the second absorption portion 3b on the second aperture 22 side is located closer to the first wall portion 23 than the surface of the first absorption portion 3a on the first aperture 21 side.

[0055] With the spectroscopic measurement reference instrument 1C configured as described above, it is possible to obtain predetermined quantitative values ​​related to the object to be measured with high accuracy, similar to the spectroscopic measurement reference instruments 1A and 1B.

[0056] In the spectroscopic measurement reference instrument 1C, the holding part 2 has a second holding member 27 that separates the absorption part 3 into a first absorption part 3a and a second absorption part 3b, and this second holding member 27 has light-shielding properties. As a result, even without placing a light-shielding cover (not shown) in the opening into which the spectroscopic measurement device 10 is fitted (the second opening 22 in the state shown in Figure 16), it is possible to prevent ambient light from entering the opening into which the spectroscopic measurement device 10 is fitted (the first opening 21 in the state shown in Figure 16), thus enabling efficient measurement by the spectroscopic measurement device 10. [Differentiation]

[0057] The present invention is not limited to the embodiments described above. For example, the adjustment unit 4 only needs to make the state of the absorption unit 3 in the first region R1 and the state of the absorption unit 3 in the second region R2 different from each other. Therefore, the first adjustment layer 41 may be arranged along the first opening 21 in the first region R1, but the second adjustment layer 42 may not be arranged along the second opening 22 in the second region R2. Conversely, the second adjustment layer 42 may be arranged along the second opening 22 in the second region R2, but the first adjustment layer 41 may not be arranged along the first opening 21 in the first region R1.

[0058] Furthermore, the adjustment section 4 is not limited to including a first adjustment layer 41 and a second adjustment layer 42. For example, as shown in Figure 17, the adjustment section 4 may be a cylindrical adjustment member 43 having a plurality of slits 43a. The adjustment member 43 is formed of, for example, a light-shielding material. In that case, two adjustment members 43 having different shapes may be arranged in the first region R1 and the second region R2 such that the entirety of the two adjustment members 43 is embedded in the absorption section 3. Alternatively, one adjustment member 43 may be arranged in only one of the first region R1 and the second region R2 such that the entirety of the one adjustment member 43 is embedded in the absorption section 3. Also, as shown in Figures 18(a) and (b), the adjustment section 4 may be an adjustment member 44 composed of a plate-shaped portion 44a and a cylindrical portion 44b. The adjustment member 44 is formed of, for example, a light-diffusing and light-transmitting material. In that case, two adjustment members 44 having different shapes may be arranged in the first region R1 and the second region R2 such that the plate-shaped portion 44a faces the first opening 21 and the second opening 22 and the cylindrical portion 44b is embedded in the absorbent portion 3. Alternatively, one adjustment member 44 may be arranged in only one of the first region R1 and the second region R2 such that the plate-shaped portion 44a faces only one of the first opening 21 and the second opening 22 and the cylindrical portion 44b is embedded in the absorbent portion 3.

[0059] Furthermore, the holding portion 2 does not need to constitute a housing that accommodates the absorption portion 3 and the adjustment portion 4, as long as it has the first opening 21 and the second opening 22. Also, the positional relationship between the first opening 21 and the second opening 22 is not limited to that described above. For example, the orientation of the first opening 21 and the orientation of the second opening 22 may be orthogonal to each other.

[0060] Furthermore, each spectroscopic measurement reference instrument 1A, 1B may be used in the spectroscopic measurement device 10 not only to calibrate the calculation coefficients a, b, c, and d in the above calculation formula, but also to obtain the calculation coefficients a, b, c, and d in the above calculation formula. In that case, it becomes unnecessary to obtain predetermined quantitative values ​​for the actual sample object S by chemical analysis such as the Soxhlet method.

[0061] Furthermore, the spectroscopic measuring device 10 is not limited to having the above-described configuration, as long as it includes a head unit 12 that emits irradiation light to be irradiated onto the target object S and into which measurement light generated in the target object S in response to the irradiation of the irradiation light is incident. The measurement target is not limited to fat, but may be other substances. For example, when the measurement target is water, since the wavelength range that water easily absorbs is 950 to 970 nm, a spectroscopic measuring device 10 that emits irradiation light in a wavelength range including this wavelength band is used, and each spectroscopic measuring reference instrument 1A, 1B uses an absorption unit 3 that absorbs light in this wavelength band. Also, when the measurement target is chlorophyll, since the wavelength range that chlorophyll easily absorbs is 670 to 690 nm, a spectroscopic measuring device 10 that emits irradiation light in a wavelength range including this wavelength band is used, and each spectroscopic measuring reference instrument 1A, 1B uses an absorption unit 3 that absorbs light in this wavelength band. [Explanation of Symbols]

[0062] 1A, 1B... Spectroscopic measurement reference instrument, 2... Holding part, 3... Absorption part, 4... Adjustment part, 5... Spacer, 10... Spectroscopic measurement device, 12... Head part, 21... First aperture, 22... Second aperture, 41... First adjustment layer, 42... Second adjustment layer, R1... First region, R2... Second region, S... Target object.

Claims

1. A spectroscopic measurement reference instrument used in a spectroscopic measurement device, which includes a head portion that emits irradiation light to be irradiated onto an object and into which measurement light generated in the object in response to the irradiation of the irradiation light is incident, A holding portion having a first opening and a second opening in which the head portion is arranged, An absorbing portion is arranged in a first region and a second region, which are set to face the first aperture and face the second aperture, and which has absorbing properties for light in a predetermined wavelength band included in the irradiated light. The device comprises an adjustment unit that causes the state of existence of the absorption unit in the first region and the state of existence of the absorption unit in the second region to be different from each other, The state of existence of the absorbing portion in the first region is at least one of the following: the position of the absorbing portion in the first region with respect to the first opening; the shape of the absorbing portion in the first region; and the proportion of the absorbing portion to the first region. Spectroscopic measurement reference instrument, wherein the state of existence of the absorbing portion in the second region is at least one of the following: the position of the absorbing portion in the second region with respect to the second aperture; the shape of the absorbing portion in the second region; and the proportion of the absorbing portion to the second region.

2. The adjustment unit is, A first adjustment layer is arranged along the first opening in the first region, The second region includes a second adjusting layer which is arranged along the second opening and has a different thickness from the first adjusting layer, The spectroscopic measurement reference instrument according to claim 1, wherein the absorption portion is located in the region of the first region where the first adjustment layer is not located and in the region of the second region where the second adjustment layer is not located.

3. The spectroscopic measurement reference instrument according to claim 2, wherein the first adjustment layer and the second adjustment layer are transparent to light in the predetermined wavelength band.

4. The first opening and the second opening are located on opposite sides of the absorption portion. A spectroscopic measurement reference instrument according to any one of claims 1 to 3, wherein a part of the first region and a part of the second region overlap each other.

5. The spectroscopic measurement reference instrument according to any one of claims 1 to 3, wherein the first opening and the second opening are opened to the same side relative to the absorption portion.

6. The reference instrument for spectroscopic measurement according to any one of claims 1 to 3, wherein the holding part is a housing that houses the absorption part and the adjustment part.

7. A spectroscopic measurement reference instrument according to any one of claims 1 to 3, further comprising spacers arranged in the first and second openings, respectively, according to the size of the head portion.

Images