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 1 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 1 for spectroscopic measurement comprises: a holding part 2 having an opening 20 at which the head part 12 is arranged; an absorption part 3 that is arranged in a target region R set so as to face the opening 20 and has absorption properties for light in a predetermined wavelength range included in the irradiation light; and an adjustment part 4 that is arranged inside the opening 20 so as to be removable from an inside of the opening 20 and adjusts the irradiation state of the irradiation light into the target region R.SELECTED DRAWING: Figure 12

Description

Technical Field

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

Background Art

[0002] There is known a spectroscopic measurement apparatus including a head unit 12 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) easily absorbs 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 spectroscopic reference device 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 measurement 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 an opening on which the head portion is arranged; an absorbing portion arranged in a target area set to face the opening and having absorbing properties for light in a predetermined wavelength band included in the irradiation light; and an adjusting portion arranged in the opening in a manner that allows it to be attached to or detached from the opening and adjusting the irradiation state of the irradiation light to the target area."

[0007] In the spectroscopic measurement reference instrument described in [1] above, the absorption section absorbs light in a predetermined wavelength band contained in the irradiated light, and the irradiation state of the irradiated light to the target area is adjusted by the adjustment section. This makes it possible to define the target area as an area corresponding to an object having a quantitative value of a first predetermined value, or as an area corresponding to an object having a quantitative value of a second predetermined value different from the first predetermined value. Therefore, for each target area where the irradiation state of the irradiated light is different from that of the others, the head of the spectroscopic measurement device is placed in the aperture, and while irradiating the target area with irradiated light, the measurement light generated in the target area is spectrally analyzed and detected. This makes 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 predetermined quantitative values ​​related to the measurement target.

[0008] The spectroscopic measurement reference instrument of the present invention may also be [2] "the spectroscopic measurement reference instrument according to [1] above, wherein the adjustment unit includes a first adjustment layer and a second adjustment layer having a different thickness from the first adjustment layer." According to the spectroscopic measurement reference instrument according to [2], the irradiation state of the irradiation light to the target area 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 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 described in [1] above, wherein the adjustment unit adjusts the transmission area of ​​the irradiation light within the aperture." According to the spectroscopic measurement reference instrument described in [4], the irradiation state of the irradiation light to the target area can be adjusted with a simple configuration.

[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 [4] above, wherein the holding part is a housing that accommodates the absorption part." According to the spectroscopic measurement reference instrument according to [5], deterioration of the absorption part can be suppressed.

[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, further comprising a spacer arranged in the opening according to the size of the head portion." According to the spectroscopic measurement reference instrument according to [6], even if the size of the head portion is changed in the spectroscopic measurement device, the positioning of the head portion with respect to the region where the absorption portion is arranged can be appropriately performed. [Effects of the Invention]

[0013] 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]

[0014] [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]It is a diagram showing the spectrum of the measurement light. [Figure 4] It is a diagram showing the steps of a method for determining the spectrum of the irradiation light. [Figure 5] It is a diagram showing the steps of a method for determining the spectrum of the irradiation light. [Figure 6] It is a diagram showing the spectrum of the irradiation light. [Figure 7] It is a diagram showing the second derivative value of the spectrum of the measurement light. [Figure 8] It is a diagram showing an example of display on the display unit of the arithmetic unit shown in FIG. 1. [Figure 9] It is a diagram showing an example of display on the display unit of the arithmetic unit shown in FIG. 1. [Figure 10] It is a perspective view of a reference device for spectroscopic measurement according to an embodiment. [Figure 11] It is a cross-sectional view of the reference device for spectroscopic measurement shown in FIG. 10. [Figure 12] It is a diagram showing an example of use of the reference device for spectroscopic measurement shown in FIG. 10. [Figure 13] It is a perspective view of a reference device for spectroscopic measurement provided with a spacer. [Figure 14] It is a perspective view of the adjustment part of a modified example. [Figure 15] It is a perspective view of the adjustment part of a modified example. [Embodiments of the Invention]

[0015] 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 explanations are omitted. [Configuration of the Spectroscopic Measurement Device]

[0016] 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.

[0017] 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.

[0018] 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).

[0019] 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.

[0020] 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.

[0021] 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]

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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]

[0026] 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.

[0027] 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.

[0028] 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 multiple regression analysis, PLS analysis, etc.

[0029] 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]

[0030] The spectroscopic measurement reference instrument 1 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 1 comprises a holding part 2, an absorption part 3, and an adjustment part 4. Hereinafter, the direction in which the aperture 20 described later is open will be referred to as the Z direction.

[0031] As shown in Figures 10 and 11, the holding part 2 houses the absorption part 3. The holding part 2 is a light-shielding housing. The holding part 2 has an opening 20. 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 opening 20 is formed in the first wall portion 23. The head portion 12 of the spectroscopic measuring device 10 is positioned in the opening 20. The opening 20 has the function of positioning the head portion 12.

[0032] The absorption unit 3 is positioned in a target region R that is set to face the aperture 20. The target region R is a region set on one side of the aperture 20 in the Z direction (inside the housing, which is the holding unit 2). The absorption unit 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 that fat easily absorbs. In that case, the material of the absorption unit 3 is, for example, solid hardened oil.

[0033] The adjustment unit 4 is positioned inside the opening 20 in a manner that allows it to be attached to or removed from the opening 20. The adjustment unit 4 adjusts the irradiation state of the irradiated light to the target area R. The irradiation state of the irradiated light to the target area R refers to the state of the irradiation range of the irradiated light in the target area R, the state of the intensity of the irradiated light in the target area R, etc.

[0034] As shown in Figures 12(a) and (b), the adjustment section 4 includes a first adjustment layer 4A and a second adjustment layer 4B having a different thickness from the first adjustment layer 4A. The first adjustment layer 4A is positioned inside the opening 20 in contact with the side surface 20a of the opening 20 and the surface 3a of the absorption section 3. The second adjustment layer 4B is positioned inside the opening 20 in contact with the side surface 20a of the opening 20 and the surface 3a of the absorption section 3. The surface 3a is the surface of the absorption section 3 exposed inside the opening 20.

[0035] The first adjustment layer 4A and the second adjustment layer 4B are transparent to light in a predetermined wavelength band included in the irradiation light emitted from the spectroscopic measuring device 10. The transparency of the first adjustment layer 4A to light in a predetermined wavelength band means that when the light passes through the first adjustment layer 4A, even if the thickness of the first adjustment layer 4A changes, the intensity profile of the light emitted from the first adjustment layer 4A is substantially the same as the intensity profile of the light incident on the first adjustment layer 4A. Similarly, the transparency of the second adjustment layer 4B to light in a predetermined wavelength band means that when the light passes through the second adjustment layer 4B, even if the thickness of the second adjustment layer 4B changes, the intensity profile of the light emitted from the second adjustment layer 4B is substantially the same as the intensity profile of the light incident on the second adjustment layer 4B. For example, if the object to be measured is fat, the materials of the first adjustment layer 4A and the second adjustment layer 4B are, for example, Teflon®.

[0036] In the spectroscopic measurement reference instrument 1, the thickness of the first adjustment layer 4A is greater than the thickness of the second adjustment layer 4B. As a result, the distance between the space inside the opening 20 and the absorption section 3 when the first adjustment layer 4A is placed inside the opening 20 is greater than the distance between the space inside the opening 20 and the absorption section 3 when the second adjustment layer 4B is placed inside the opening 20. For example, if the object to be measured is fat, the target region R when the first adjustment layer 4A is placed inside the opening 20 corresponds to an object S having a fat percentage of a first predetermined value, and the target region R when the second adjustment layer 4B is placed inside the opening 20 corresponds to an object S having a fat percentage of a second predetermined value which is higher than the first predetermined value.

[0037] The spectroscopic measurement reference instrument 1, configured as described above, is used as follows. First, as shown in Figure 12(a), the first adjustment layer 4A is placed inside the aperture 20. In this state, the head portion 12 of the spectroscopic measurement device 10 is placed inside the aperture 20. More specifically, the head portion 12 is placed inside the aperture 20 such that the end face 12a of the head portion 12 is in contact with the first adjustment layer 4A and the side surface 12b of the head portion 12 is in contact with the side surface 20a of the aperture 20. 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 placed inside the aperture 20, the spectroscopic measurement device 10 irradiates the target region R with irradiation light, spectrally analyzes and detects the measurement light generated in the target region R, and outputs the detection signal of the measurement light to the computing device 100.

[0038] Next, the first adjustment layer 4A is removed from inside the opening 20, and the second adjustment layer 4B is placed inside the opening 20 as shown in Figure 12(b). In this state, the head portion 12 of the spectroscopic measuring device 10 is placed inside the opening 20. More specifically, the head portion 12 is placed inside the opening 20 such that the end face 12a of the head portion 12 is in contact with the second adjustment layer 4B and the side surface 12b of the head portion 12 is in contact with the side surface 20a of the opening 20. With the head portion 12 placed inside the opening 20, the spectroscopic measuring device 10 irradiates the target region R with illumination light, spectrally analyzes and detects the measurement light generated in the target region R, and outputs the detection signal of the measurement light to the computing device 100.

[0039] The calculation unit 100 stores data relating to the quantitative value of the target region R when the first adjustment layer 4A is placed in the aperture 20, and data relating to the quantitative value of the target region R when the second adjustment layer 4B is placed in the aperture 20. The data relating to the quantitative value of the target region R when the first adjustment layer 4A is placed in the aperture 20 indicates that the target region R corresponds to an object S having a quantitative value of a first predetermined value. The data relating to the quantitative value of the target region R when the second adjustment layer 4B is placed in the aperture 20 indicates that the target region R 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 value of the target region R and the detection signal of the measurement light of the acquired target region R, the calculation unit 100 calibrates the calculation coefficients a, b, c, and d in the above calculation formula.

[0040] 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 a spacer 5 that is placed in the opening 20 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 opening 20. When the spacer 5 is placed in the opening 20, the head unit 12 is positioned in the opening 20 such that the end face 12a of the head unit 12 is in contact with the adjustment unit 4 and the side surface 12b of the head unit 12 is in contact with the side surface 51a of the main body 51.

[0041] As explained above, in the spectroscopic measurement reference instrument 1, the absorption section 3 absorbs light in a predetermined wavelength band included in the irradiated light, and the irradiation state of the irradiated light to the target region R is adjusted by the adjustment section 4. This makes it possible to set the target region R to a region corresponding to "an object S having a quantitative value of a first predetermined value" or to a region corresponding to "an object S having a quantitative value of a second predetermined value different from the first predetermined value". Therefore, for each target region R where the irradiation state of the irradiated light is different from that of the others, the head section 12 of the spectroscopic measurement device 10 is placed in the aperture 20, and while irradiating the target region R with irradiated light, the measurement light generated in the target region R is spectrally analyzed and detected. This makes 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 1 enables highly accurate acquisition of predetermined quantitative values ​​related to the measurement target.

[0042] In the spectroscopic measurement reference instrument 1, the adjustment unit 4 includes a first adjustment layer 4A and a second adjustment layer 4B having a different thickness from the first adjustment layer 4A. This allows for adjustment of the irradiation state of the light applied to the target region R with a simple configuration.

[0043] In the spectroscopic measurement reference instrument 1, the first adjustment layer 4A and the second adjustment layer 4B are transparent to light in a predetermined wavelength band. This prevents the adjustment layers from affecting the characteristics of the irradiated light.

[0044] In the spectroscopic measurement reference instrument 1, the holding unit 2 is a housing that contains the absorption unit 3. This makes it possible to suppress the deterioration of the absorption unit 3.

[0045] In the spectroscopic measurement reference instrument 1, spacers 5 are placed in the aperture 20 according to the size of the head portion 12. This allows for proper positioning of the head portion 12 relative to the region where the absorption portion 3 is located, even if the size of the head portion 12 is changed in the spectroscopic measurement device 10. [Differentiation]

[0046] The present invention is not limited to the embodiments described above. For example, the adjustment unit 4 only needs to adjust the irradiation state of the irradiation light to the target region R. Therefore, measurements by the spectroscopic measuring device 10 may be performed with only one of the first adjustment layer 4A and the second adjustment layer 4B placed in the aperture 20, or measurements by the spectroscopic measuring device 10 may be performed with neither the first adjustment layer 4A nor the second adjustment layer 4B placed in the aperture 20.

[0047] Furthermore, the adjustment unit 4 is not limited to including the first adjustment layer 4A and the second adjustment layer 4B, but may also adjust the transmission area of ​​the irradiated light within the opening 20. In that case as well, the irradiation state of the irradiated light to the target area R can be adjusted with a simple configuration.

[0048] As an example, as shown in Figure 14, the adjustment unit 4 may include a light-transmitting member 41, a disc-shaped first light-shielding member 42 having an opening 42a, and a disc-shaped second light-shielding member 43 having an opening 43a. In the adjustment unit 4 shown in Figure 14, the light-transmitting member 41 is composed of a disc portion 411 and an annular portion 412. The annular portion 421 is provided on the surface 411a of the disc portion 411. An opening 411b is formed in the center of the disc portion 411. The first light-shielding member 42 is fitted inside the annular portion 412 on the surface 411a. The second light-shielding member 43 is fitted outside the annular portion 412 on the surface 411a. The light-transmitting member 41 and the second light-shielding member 43 fit into the opening 20 of the holding unit 2. According to the adjustment unit 4 shown in Figure 14, by selecting combinations such as "light-transmitting member 41 and first light-shielding member 42", "light-transmitting member 41 and second light-shielding member 43", and "light-transmitting member 41, first light-shielding member 42 and second light-shielding member 43", the transmission area of ​​the irradiated light within the aperture 20 can be adjusted, making it possible to adjust the irradiation state of the irradiated light to the target area R. Alternatively, multiple light-transmitting members 41 with different widths of the annular portion 412 may be prepared. In this case as well, the transmission area of ​​the irradiated light within the aperture 20 can be adjusted by the difference in the width of the annular portion 412. Note that apertures 411b and 42a are apertures for allowing measurement light to pass through.

[0049] Furthermore, as shown in Figures 15(a) and (b), the adjustment unit 4 may be a disc-shaped light-shielding member 44 having multiple openings 44a and one opening 44b. The light-shielding member 44 fits into the opening 20 of the holding unit 2. The multiple openings 44a are formed around the opening 44b so as to surround it. The opening 44b is formed in the center of the light-shielding member 44. The multiple openings 44a are openings for allowing the irradiation light to pass through. The opening 44b is an opening for allowing the measurement light to pass through. According to the adjustment unit 4 shown in Figures 15(a) and (b), by selecting whether or not to include the light-shielding member 44, or by selecting a light-shielding member 44 with a different number and shape of multiple openings 44a, the transmission area of ​​the irradiation light within the opening 20 can be adjusted, making it possible to adjust the irradiation state of the irradiation light to the target area R.

[0050] Furthermore, the holding portion 2 does not need to constitute a housing that accommodates the absorption portion 3, as long as it has an opening 20. Also, the holding portion 2 may have multiple openings 20.

[0051] Furthermore, each spectroscopic measurement reference instrument 1 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.

[0052] 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 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 an absorption unit 3 that absorbs light in this wavelength band is used in each spectroscopic measuring reference instrument 1. 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 an absorption unit 3 that absorbs light in this wavelength band is used in each spectroscopic measuring reference instrument 1. [Explanation of Symbols]

[0053] 1...Spectroscopic measurement reference instrument, 2...Holding part, 3...Absorption part, 4...Adjustment part, 5...Spacer, 10...Spectroscopic measurement device, 12...Head part, 20...Aperture, 4A...First adjustment layer, 4B...Second adjustment layer, R...Target area, 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 an opening in which the head portion is arranged, An absorbing portion is provided which is arranged in a target region set on one side of the opening in the direction in which the opening is open, and which has the ability to absorb light of a predetermined wavelength band included in the irradiated light, The system includes an adjustment unit which is detachably positioned within the opening and adjusts the irradiation state of the irradiation light to the target area, A spectroscopic measurement reference instrument, wherein the irradiation state of the irradiation light to the target region is at least one of the state of the irradiation range of the irradiation light in the target region and the state of the intensity of the irradiation light in the target region.

2. The spectroscopic measurement reference instrument according to claim 1, wherein the adjustment section includes a first adjustment layer and a second adjustment layer having a different thickness from the first adjustment layer.

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 adjustment unit adjusts the transmission region of the irradiated light within the aperture, as described in claim 1.

5. The reference instrument for spectroscopic measurement according to any one of claims 1 to 4, wherein the holding portion is a housing that houses the absorption portion.

6. A spectroscopic measurement reference instrument according to any one of claims 1 to 4, further comprising a spacer arranged in the opening according to the size of the head portion.

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