JP2009300182A - Calibrating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a calibrating device capable of precisely calibrating an optical measuring device for measuring a particle size distribution. <P>SOLUTION: The calibrating device is equipped with a plurality of transparent base materials each of which has an antireflection film provided to at least one of both surfaces, standard particles having a refractive index different from that of the transparent base materials and transmittance almost coinciding with that of a measuring target and fixed to at least one of both surfaces of each of the transparent base materials and the spacers alternately stacked to the transparent base materials and almost vertically holding both surfaces of each of the transparent base materials with respect to an optical axis. In the stacked transparent base materials, the distance between both end parts on an incident side and an emitting side is allowed to almost coincide with the light path length of the measuring target and one surfaces having the standard particles fixed thereto of the transparent base materials and the cross section of the measuring target corresponding to the same position are allowed to almost coincide with each other in particle size distribution, number per a unit area and average particle interval. Further, in the stacking direction, the distance between the surfaces, to which the adjacent standard particles are respectively fixed, of the transparent base materials almost coincides with the average particle interval at the position corresponding to the measuring target. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a calibration apparatus for calibrating an optical measurement apparatus that measures a particle size distribution of a measurement object that is three-dimensionally arranged.

  Conventionally, image measurement such as shadow photography and scattered light photography, and laser diffraction and scattering methods have been used as devices for measuring the particle size distribution of measured objects, which are aggregates of particles such as fuel particles, powder, and bubbles in liquids. An optical measuring device is known. For example, Patent Document 1 and Non-Patent Documents 1 and 2 show a calibration device (calibration sample) that is applied to calibration such as a binarization level in the optical measurement device.

  The calibration apparatus disclosed in Patent Document 1 is a standard sample embedded in glass by placing a standard sample (standard particles) on one surface of a glass substrate (transparent substrate) and then pouring molten glass. It has become.

  Moreover, the calibration apparatus shown by the nonpatent literature 1 is laid down so that the opaque disk (standard particle) which consists of a chromium thin film may not overlap on a glass substrate (transparent base material).

The calibration device shown in Non-Patent Document 2 is a device in which spherical test particles (standard particles) having a predetermined particle size distribution are dispersed in a liquid by stirring or the like.
JP 2001-165846 A Yamakawa et al., 4 others, “Development of three-dimensional measurement system of spray particle size by pulsed laser holography method”, Symposium on Atomization, 1999, Vol. 23, No. 8, p.19-26 Mori, “Round Robin Test Results of Test Particles Using a Laser Diffraction / Scattering Particle Size Distribution Measuring Device”, Powder and Industry, 2006, Vol. 38, No. 6, p. 35-41

  By the way, in such a calibration apparatus, the accuracy of calibration can be increased as the dispersion state of the standard particles is made closer to the measurement object.

  However, the calibration apparatus shown in Patent Document 1 and Non-Patent Document 1 has a so-called two-dimensional structure in which standard particles are arranged on a transparent base material, and many times due to particles in the optical axis direction of measurement light. The influence of multiple scattering in which the measurement light is scattered is not considered. Therefore, these calibration devices use optical measurement to measure the particle size distribution of an object to be measured (three-dimensionally arranged object to be measured) in which particles such as fuel fine particles, powder, and bubbles in a liquid are three-dimensionally arranged. Even if it is applied to the calibration of the device, it cannot be calibrated with high accuracy.

  Further, in the case of the calibration apparatus shown in Patent Document 1, since molten glass is poured, the standard sample placed on the glass substrate is misaligned, and the standard sample placement on the substrate is biased (for example, predetermined average particles). Can't ensure spacing). Therefore, even when viewed two-dimensionally, it is difficult to set the dispersed state of the particles to a predetermined state close to the measured object.

  Furthermore, in the case of the calibration apparatus shown in Non-Patent Document 2, the position of the standard particles in the liquid changes with time (from moment to moment), so at the measurement point (focus position in the case of image measurement by camera photography). It is unclear whether the dispersion state of the standard particles is close to that of the object to be measured. In particular, when the dispersion states at different positions (cross sections) are different from each other in the optical axis direction of the measurement light, calibration cannot be performed with high accuracy.

  In view of the above problems, an object of the present invention is to provide a calibration apparatus that can accurately calibrate an optical measurement apparatus that measures the particle size distribution of a three-dimensionally arranged measurement object.

  In order to achieve the above object, the invention described in claim 1 is a calibration device for calibrating an optical measurement device for measuring the particle size distribution of a three-dimensionally arranged object to be measured, the measurement of the optical measurement device. A transparent substrate that is transparent to light and has an antireflection film provided on at least one of both surfaces through which the measurement light is transmitted, and a transmission that substantially matches the refractive index and the object to be measured different from the transparent substrate. The standard particles fixed directly or via an antireflection film and the transparent base material are alternately laminated in the optical axis direction of the measurement light on at least one of both surfaces of each transparent base material. The surfaces of the transparent substrates through which the measurement light is transmitted are kept substantially parallel to each other (in other words, both the surfaces of the transparent substrates through which the measurement light is transmitted are substantially perpendicular to the optical axis; And a plurality of transparent substrates laminated via spacers In this case, the distance between the incident side end portion and the emission side end portion of the measurement light is substantially the same as the optical path length of the measurement light in the measured object, and the standard particles fixed on the same surface of the transparent substrate are The particle size distribution, the number per unit area, and the average particle interval are substantially the same as the particle size distribution, the number per unit area, and the average particle interval in the cross section corresponding to the same position of the object to be measured. In the transparent substrate including the antireflection film, the distance between the surfaces of the transparent substrate to which the standard particles adjacent to each other are fixed substantially coincides with the average particle spacing at the corresponding position in the measured object. The thickness and the thickness of the spacer are respectively set.

  In the present invention, the standard particles are fixed on the surface of the transparent substrate, the transparent substrate having the standard particles is laminated in multiple layers along the optical axis of the measurement light, and the calibration device is configured. The distance between the incident side end portion and the emission side end portion of the transparent base material is substantially coincident with the optical path length of the measurement light in the measured object.

  In addition, the standard particles fixed on the surface of the transparent substrate have the same particle size distribution, the number per unit area, and the average particle interval on the same surface, and the positional relationship in which the distance from the measurement light incident site is substantially equal to each other. Are substantially the same as the particle size distribution, the number per unit area, and the average particle spacing in the cross section of the object to be measured. That is, in the lamination direction of the transparent base material (the optical axis direction of the measurement light), the standard particles fixed on the surface of any transparent base material are cross-sections of the measured objects whose optical positions are substantially equal. It is almost equal to the particle dispersion state (in the case of camera photography, at the same focal position on the object to be measured). In addition, as the transparent base material of each layer to which the standard particles are fixed, the data of the dispersion state of the particles in the cross section of the measurement object having substantially the same optical position (particle size distribution, number per unit area, Based on the average particle spacing), standard particles with a known diameter are fixed while being placed on the surface of the transparent substrate by spraying with an airbrush or a known dry dispersion unit, and then optically observed with a microscope or the like. As a result of the measurement, a cross-section corresponding to the object to be measured and a substantially coincident dispersion state are used.

  In addition, in the stacking direction, an antireflection film is included so that the distance between the surfaces of the transparent base material to which the standard particles adjacent to each other are fixed substantially coincides with the average particle spacing at the corresponding position in the measurement object. The thickness of the transparent substrate and the thickness of the spacer are set. That is, the standard particles are substantially coincident with the average particle spacing at the site of the measurement object having a substantially equal optical position in the stacking direction.

  As described above, in the present invention, the standard particles are three-dimensionally arranged in a state closer to the dispersed state of the particles in the measurement object in which the particles are three-dimensionally arranged. Therefore, if the above-described calibration apparatus is used, multiple scattering at the object to be measured can be reproduced, thereby accurately calibrating the optical measuring apparatus that measures the particle size distribution of the object to be measured arranged three-dimensionally. be able to.

  Further, in the present invention, an antireflection film (so-called AR coating) is provided on at least one of both surfaces of the transparent base material, thereby suppressing reflection on the surface of the transparent base material provided with the antireflection film. . Therefore, the amount of transmitted light can be secured while the transparent substrate is laminated in multiple layers. Preferably, it is good to set it as the structure by which the antireflection film was provided in both surfaces of the transparent base material. In addition, by providing an antireflection film, it is possible to suppress ghosts and flares due to repeated reflections (suppress the decrease in image contrast), and to further improve calibration accuracy.

  In the first aspect of the present invention, as described in the second aspect, the standard particles may be made of resin and fixed to the transparent substrate by welding of the surface thereof. In this way, when using resin standard particles, heating is performed so that only the surface of the standard particles melts (softens), so that the standard particles are transparent while ensuring the particle shape without the need for a separate adhesive or the like. Since it can be fixed (welded) to the substrate, it is optically preferable.

  In the invention according to claim 1 or 2, as described in claim 3, the thickness of the transparent substrate including the standard particles fixed to both surfaces of each transparent substrate and including an antireflection film. It is preferable that the thickness of the spacer and the spacer be substantially the same as the average particle spacing at the corresponding position in the measurement object.

  According to this, since the standard particles are fixed on both surfaces of the transparent base material, if the average particle interval is the same, the transparent base material and the transparent base material are compared with the structure in which the standard particles are fixed only on one surface. The thickness of the spacer can be increased. In particular, as the thickness of the transparent base material decreases, the flatness decreases due to the characteristics of mechanical processing. Therefore, distortion is likely to occur in the image, but according to the above, it is difficult to generate such distortion. .

  Next, the invention described in claim 4 is a calibration device for calibrating an optical measurement device for measuring the particle size distribution of a three-dimensionally arranged object to be measured, which is transparent to the measurement light of the optical measurement device. Each transparent substrate having a plurality of plate-like transparent base materials having a refractive index n1, a refractive index n2 different from the refractive index n1, and a transmittance substantially coincident with the measured object is transmitted. Standard particles fixed to at least one of both surfaces of the base material and transparent base material are alternately laminated in the optical axis direction of the measurement light, and the surfaces of the transparent base materials through which the measurement light is transmitted are substantially parallel to each other. (In other words, in the region between the spacers that keep both surfaces of each transparent substrate through which the measurement light is transmitted substantially perpendicular to the optical axis and the opposite surfaces of the adjacent transparent substrates through the spacers) Filled, transparent to the measuring light, and having a refractive index n3 that approximately matches the refractive index n1 In the plurality of transparent substrates stacked via the spacers, the distance between the measurement light incident side end and the output side end is the measurement light in the object to be measured. The particle diameter distribution, the number per unit area, and the average particle spacing of the standard particles that are substantially the same as the optical path length and fixed on the same surface of the transparent substrate are cross sections corresponding to the same position of the object to be measured. The distance between the surfaces of the transparent base material, which is substantially the same as the particle size distribution, the number per unit area, and the average particle spacing and in which the standard particles adjacent to each other are fixed in the stacking direction, corresponds to the object to be measured. The thickness of the transparent substrate and the thickness of the spacer are respectively set so as to substantially coincide with the average particle spacing at the position.

  Thus, also in the present invention, the standard particles are three-dimensionally arranged in a state closer to the dispersed state of the particles in the three-dimensionally arranged measurement object, as in the first aspect of the invention. Therefore, if the above-described calibration apparatus is used, multiple scattering at the object to be measured can be reproduced, thereby accurately calibrating the optical measuring apparatus that measures the particle size distribution of the object to be measured arranged three-dimensionally. be able to.

  Further, in the present invention, the refractive index n1 of the transparent base material and the refractive index n3 of the filler are substantially matched, whereby the standard particles are three-dimensionally arranged in a uniform transparent member having almost no refractive index distribution. It has a configuration. Therefore, the calibration device is in a state closer to the state of the measured object in the medium (atmosphere), such as fuel fine particles injected into the air or bubbles in the liquid, thereby further improving the accuracy of calibration. Can do. Further, since the reflection on the surface of the transparent base material facing the adjacent transparent base material hardly occurs, the amount of transmitted light can be ensured. Further, it is possible to suppress a decrease in the contrast of the image due to repeated reflection, and to further improve the accuracy of calibration.

  In addition, when suppressing reflection by providing an antireflection film on the surface of the transparent substrate, the antireflection film is also affected by the flatness of the transparent substrate. Distortion tends to occur. On the other hand, in this invention, since a filler is filled between the opposing surfaces of adjacent transparent base materials, such distortion can be reduced.

  Next, the invention according to claim 5 is a calibration device for calibrating an optical measurement device for measuring the particle size distribution of a three-dimensionally arranged object to be measured, which is transparent to the measurement light of the optical measurement device. Each having a plurality of plate-like transparent base materials having a refractive index n1, a refractive index n2 larger than the refractive index n1, and a transmittance substantially coincident with the measured object, and through which measurement light is transmitted. The standard particles fixed to at least one of both surfaces of the transparent base material and the transparent base material are alternately laminated in the optical axis direction of the measurement light, and the surfaces of the transparent base materials through which the measurement light is transmitted are substantially the same. Keep in parallel (in other words, between the spacer that keeps both surfaces of each transparent substrate through which the measurement light is transmitted substantially perpendicular to the optical axis, and the opposite surfaces of the transparent substrate adjacent to each other through the spacer. The area is filled, transparent to the measuring light of the optical measuring device, and from the refractive index n1 And a filler having a refractive index n3 that is smaller than a refractive index of 1. In a plurality of transparent members stacked via a spacer, the measurement light incident side end and the output side end The distance between the reference particles is substantially the same as the optical path length of the measurement light in the object to be measured, and the particle size distribution, the number per unit area, and the average particle interval of the standard particles fixed on the same surface of the transparent substrate are as follows. The surface of the transparent base material in which the standard particles adjacent to each other are fixed substantially in the laminating direction, with the particle size distribution, the number per unit area, and the average particle spacing in the cross section corresponding to the same position of the measurement object The thickness of the transparent substrate and the thickness of the spacer are respectively set so that the distance between them substantially coincides with the average particle spacing at corresponding positions in the object to be measured.

  Thus, also in the present invention, the standard particles are three-dimensionally arranged in a state closer to the dispersed state of the particles in the three-dimensionally arranged measurement object, as in the first aspect of the invention. Therefore, if the above-described calibration apparatus is used, multiple scattering at the object to be measured can be reproduced, thereby accurately calibrating the optical measuring apparatus that measures the particle size distribution of the object to be measured arranged three-dimensionally. be able to.

  Further, in the present invention, the refractive index n2 of the standard particles is larger than the refractive index n1 of the transparent base material, and the particles appear as shadows, for example, when a photograph of fuel fine particles injected into the air is taken. It is a calibration device for the measured object. In such a calibration apparatus, a filler having a refractive index n3 that is transparent to the measurement light and is smaller than the refractive index n1 and larger than the refractive index 1 in a region between the opposing surfaces of adjacent transparent substrates. Is filled. Therefore, since the difference in refractive index between two adjacent media is smaller than the configuration in which air (refractive index 1) is adjacent to the surface of the transparent substrate, reflection on the surface of the transparent substrate is reduced, and the transparent substrate The amount of transmitted light can be ensured while the configuration is laminated in multiple layers. In addition, it is possible to suppress the deterioration of the contrast of the image due to repetitive reflection and to further improve the calibration accuracy. Furthermore, since the refractive index n3 is smaller than the refractive index n1, even when the refractive index n1 and the refractive index n2 are close to each other, it is possible to suppress a decrease in image contrast.

  In addition, when an antireflection film is provided on the surface of the transparent substrate, the antireflection film is affected by the flatness of the transparent substrate, so that the thinner the transparent substrate, the more likely the image is distorted. On the other hand, in this invention, since a filler is filled between the opposing surfaces of adjacent transparent base materials, such distortion can be reduced.

  Next, the invention described in claim 6 is a calibration device for calibrating an optical measurement device for measuring the particle size distribution of a three-dimensionally arranged object to be measured, which is transparent to the measurement light of the optical measurement device. Each of the transparent substrates having a plurality of flat transparent substrates having a refractive index n1, a refractive index n2 smaller than the refractive index n1, and a transmittance substantially equal to the measurement object are transmitted. Standard particles fixed to at least one of both surfaces of the base material and transparent base material are alternately laminated in the optical axis direction of the measurement light, and the surfaces of the transparent base materials through which the measurement light is transmitted are substantially parallel to each other. (In other words, in the region between the spacers that keep both surfaces of each transparent substrate through which the measurement light is transmitted substantially perpendicular to the optical axis and the opposite surfaces of the adjacent transparent substrates through the spacers) Filled, transparent to the measurement light of the optical measuring device, greater than the refractive index n1, A filler having a refractive index n3 whose difference from the refractive index n1 is smaller than the difference between the refractive index n1 and the refractive index 1. In a plurality of transparent members stacked via spacers, measurement is performed. The distance between the light incident side end and the light exit end is substantially the same as the optical path length of the measurement light in the measured object, and the particle size distribution of the standard particles fixed on the same surface of the transparent substrate, The number per unit area and the average particle spacing are substantially the same as the particle size distribution, the number per unit area and the average particle spacing in the cross section corresponding to the same position of the object to be measured, and adjacent to each other in the stacking direction. The thickness of the transparent substrate and the thickness of the spacer are set so that the distance between the surfaces of the transparent substrate to which the standard particles to be fixed are substantially the same as the average particle spacing at the corresponding position on the measured object It is characterized by being.

  Thus, also in the present invention, the standard particles are three-dimensionally arranged in a state closer to the dispersed state of the particles in the three-dimensionally arranged measurement object, as in the first aspect of the invention. Therefore, if the above-described calibration apparatus is used, multiple scattering at the object to be measured can be reproduced, thereby accurately calibrating the optical measuring apparatus that measures the particle size distribution of the object to be measured arranged three-dimensionally. be able to.

  In the present invention, the refractive index n2 of the standard particles is smaller than the refractive index n1 of the transparent substrate. For example, for a measured object in which the particles appear bright as in the case of taking a shadow photograph of bubbles in the liquid. It is a calibration device. In such a calibration apparatus, the region between the adjacent surfaces of the adjacent transparent base materials is transparent to the measurement light, is larger than the refractive index n1, and the difference from the refractive index n1 is refracted from the refractive index n1. A filler having a refractive index n3 smaller than the difference from the rate 1 is filled. Therefore, since the difference in refractive index between two adjacent media is smaller than the configuration in which air (refractive index 1) is adjacent to the surface of the transparent substrate, reflection on the surface of the transparent substrate is reduced, and the transparent substrate The amount of transmitted light can be ensured while the configuration is laminated in multiple layers. In addition, it is possible to suppress the deterioration of the contrast of the image due to repetitive reflection and to further improve the calibration accuracy. Further, since the refractive index n3 is larger than the refractive index n1, even if the refractive index n1 and the refractive index n2 are close to each other, it is possible to suppress a decrease in contrast of the image.

  In addition, when an antireflection film is provided on the surface of the transparent substrate, the antireflection film is affected by the flatness of the transparent substrate, so that the thinner the transparent substrate, the more likely the image is distorted. On the other hand, in this invention, since a filler is filled between the opposing surfaces of adjacent transparent base materials, such distortion can be reduced.

  In the invention according to any one of claims 4 to 6, for example, as described in claim 7, the standard particles may be made of resin and fixed to the transparent base material by welding of the surface thereof. Since the effect of this invention is the same as the effect of the invention of Claim 2, the description is abbreviate | omitted.

  Further, in the invention according to any one of claims 4 to 6, for example, as described in claim 8, it has a refractive index n4 that substantially matches the refractive index n1, and is provided on at least one of both surfaces of the transparent substrate. It is good also as a structure further equipped with the adhesive layer which consists of provided ultraviolet curing resin, and the standard particle was adhere | attached and fixed to the adhesive layer in each transparent base material.

  According to this, since the refractive index of the adhesive layer is substantially the same as that of the transparent substrate, the optical loss in the adhesive layer is reduced while the standard particles are fixed to the transparent substrate by the adhesive layer. be able to. Particularly, in the configuration according to claim 4, the refractive indexes of the transparent base material, the adhesive layer, and the filler are substantially matched, so that the standard particles are three-dimensionally within a uniform transparent member having almost no refractive index distribution. It becomes an arrangement.

  Further, in the invention according to any one of claims 4 to 8, as described in claim 9, the standard particles are respectively fixed to both surfaces of each transparent substrate, and the thickness of the transparent substrate and the spacer The thickness may be substantially the same as the average particle spacing at the corresponding position in the object to be measured. Since the effect of this invention is the same as the effect of the invention of Claim 3, the description is abbreviate | omitted.

  In the invention according to any one of claims 1 to 9, as described in claim 10, the plurality of transparent base materials are stacked on each other via the spacers, and the holding member from both ends in the stacking direction. It is good to adopt a configuration that is sandwiched by and integrated. According to this, since the plurality of transparent base materials are integrated by sandwiching by the holding member, it is possible to easily replace some of the transparent base materials.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram showing a schematic configuration of particle size distribution measurement by an optical measurement device for a measurement object. FIG. 2 is a cross-sectional view illustrating a schematic configuration of the calibration apparatus according to the first embodiment. 3 is a cross-sectional view taken along the line III-III shown in FIG. FIG. 4 is a cross-sectional view showing a schematic configuration of a laminated unit which is a main characteristic portion of the calibration apparatus shown in FIG.

  The calibration apparatus shown in the present embodiment is an image measurement such as shadow photography / scattered light photography for measuring the particle size distribution of a measurement object in which particles such as fuel fine particles, powder, and bubbles in a liquid are three-dimensionally arranged, and laser diffraction. -It can be applied to the calibration of optical measuring devices using the scattering method. As an example applied to image measurement by shadow photography, the calibration apparatus shown in the present embodiment is an aggregate of fuel fine particles 100a (hereinafter simply referred to as particles 100a) injected from an injector 101, as shown in FIG. A predetermined measurement light 102 (hereinafter simply referred to as measurement light) is irradiated from a light source (not shown) to a predetermined position of the spray as the measurement object 100, and a predetermined area (imaging image) of the measurement object 102 irradiated with the measurement light 102. This is a device for calibrating an optical measuring device that calculates a particle size distribution based on image data obtained by imaging an area) with an imaging device 103 such as a CCD camera installed coaxially with the measuring light 102. . As shown in FIG. 1, the length (optical path length) of the irradiated portion of the measurement light 102 in the measurement object 100 is the length L. That is, the measurement light 102 is irradiated to the portion of the width L of the measured object 100.

  As shown in FIG. 2, the calibration device 10 includes a laminated unit 20 that is a main characteristic part, a protective member 30 that protects an incident side end and an outgoing side end of measurement light in the laminated unit 20, the laminated unit 20, and the protective member. It has a holder 40 for holding 30 in a laminated state.

  The laminated unit 20 is a part of the calibration apparatus 10 that simulates a measurement object in order to calibrate the optical measurement apparatus. Specifically, as shown in FIG. 4, as main parts, a plurality of transparent base materials 21, an antireflection film 22 provided on the surface 21 a of the transparent base material 21, and standard particles fixed to the transparent base material 21. 23, spacers 24 are alternately stacked on the transparent base material 21 on which the standard particles 23 are fixed.

  The transparent substrate 21 is a flat member that is transparent to the measurement light 102 and supports the standard particles 23 on the surface 21a through which the measurement light 102 is transmitted. A plurality of transparent base materials 21 to which the standard particles 23 are fixed are stacked in the optical axis direction of the measurement light 102 via the spacers 24. In the present embodiment, the transparent substrate 21 is formed using a material having a melting point temperature higher than that of the material constituting the standard particles 23 and a low refractive index (for example, crown glass having a refractive index of 1.524). Further, the number of the transparent base materials 21 is determined by the length L of the optical path length and the average particle interval together with the number of the spacers 24.

  The antireflection film 22 is provided on at least one of the incident-side surface 21a and the emission-side surface 21a, which is a transmission surface of the measurement light 102, in each transparent substrate 21, and cancels the reflection of the measurement light on the surface 21a. It is a single-layer or multilayer thin film (so-called AR coat) that is reduced by interference. In the present embodiment, as shown in FIG. 4, in each transparent base material 21, an antireflection film 22 is provided on both the entire surface 21a on the incident side and the entire surface 21a on the emission side.

  In the laminated unit 20 in which a plurality of transparent base materials 21 including the antireflection film 22 are laminated, the distance between the outer surfaces (including the antireflection film 22) in the stacking direction (the optical axis direction of the measurement light 102) ( The distance between the incident-side end 20a and the emission-side end 20b of the measuring light 102 is substantially the same as the length L of the optical path length of the measuring light 102 in the measured object 100. Further, in the stacking direction, the thickness of each transparent base material 21 including the antireflection film 22 provided on both surfaces 21a is substantially the same as the average particle spacing at corresponding positions in the measured object 100. Yes. The corresponding position is a position based on the incident side end (or the emission side end) of the measurement light 102. That is, in the measured object 100, when the average particle spacing in the vicinity of X is about 100 μm from the incident side end of the measurement light 102, the distance from the incident side end 20 a is about X in the laminated unit 20. The thickness of the transparent substrate 21 (including the antireflection film 22) is about 100 μm.

  The standard particles 23 are sample particles (beads) having a known diameter such as a sphere or an ellipse (sphere) having a refractive index different from that of the transparent substrate 21 and a transmittance substantially matching the measured object 100 (particle 100a). Yes, it is fixed to at least one of the both surfaces 21 a of each transparent substrate 21 directly or via an antireflection film 22. The standard particles 23 are portions corresponding to the particles 100a of the measurement object 100. The standard particles 23 fixed on the same surface 21a of the transparent substrate 21 have a particle size distribution, a number per unit area, and an average. The particle interval is substantially the same as the particle size distribution, the number per unit area, and the average particle interval in the cross section at the corresponding position in the measurement object 100. That is, in any of the surfaces 21a on which the standard particles 23 are fixed among the plurality of laminated transparent base materials 21, the particle size distribution, the number per unit area, and the average particle spacing are the same as those of the measurement target 100. It is substantially the same as the particle size distribution, the number per unit area, and the average particle spacing in a cross section in which the optical positions in the imaging area are substantially equal (the focal positions are equal). Therefore, depending on the dispersion state of the particles 100a in the measurement object 100, the particle size distribution, the number per unit area, and the average particle interval are constant in the stacking direction regardless of the distance from the incident side end of the measurement light 102. In some cases, the particle size distribution, the number per unit area, and the average particle spacing may differ depending on the distance from the incident side end.

  In the present embodiment, a plurality of types of spherical sample particles with known diameters are used so that the standard particles 23 substantially coincide with the particle size distribution and the number per unit area in the cross section at the corresponding position in the measurement object 100. It is composed of a mixture. Further, as the standard particles 23, standard particles made of a resin material having a lower melting point than that of the transparent substrate 21 and a large refractive index (for example, crosslinked polystyrene having a refractive index of 1.59) are employed. Then, resin standard particles 23 are arranged in the imaging area (center portion) irradiated with the measurement light 102 on the surface 21 a of the transparent base material 21, and only the surface of the standard particles 23 is melted and welded to the antireflection film 22. Has been. That is, the standard particles 23 are fixed to the transparent substrate 21 via the antireflection film 22.

  The spacers 24 are alternately laminated with the transparent base material 21 in the optical axis direction of the measurement light 102, and both surfaces 21 a of the respective equivalent base materials 21 through which the measurement light 102 is transmitted are approximately the optical axis of the measurement light 102. It is a flat member having a predetermined thickness so as to keep the surfaces 21a of the respective transparent base materials 21 substantially parallel to each other and to maintain a predetermined distance between the adjacent transparent base materials 21 so as to be vertical. The spacer 24 is disposed on the peripheral portion surrounding the imaging area (center portion) irradiated with the measurement light 102 on the surface 21 a of the transparent base material 21. In the present embodiment, as shown in FIG. 3, each spacer 24 has an annular shape surrounding the imaging area, and in the stacking direction, the thickness of each spacer 24 is the same as the thickness of the transparent substrate 10 in the measured object 100. The thickness is approximately the same as the average particle spacing at the corresponding position.

  In the laminated unit 20 configured as described above, air 25 is filled in the region between the opposing surfaces 21 a (between the antireflection films 22) of the transparent base materials 21 adjacent to each other via the spacer 24. As a result, the laminated unit 20 has the standard particles 23 (refractive index larger than that in the transparent substrate 21 (refractive index 1.524) and air (refractive index 1), that is, in a medium having a small refractive index. Refractive index 1.59) is arranged three-dimensionally (configuration in which standard particles 23 appear as shadows). And thereby, the structure which imitated the to-be-measured object 100 (structure which the particle | grains 100a appear as a shadow) by which the fuel microparticles | fine-particles 100a (n-heptane of refractive index 1.3876) are arrange | positioned three-dimensionally in air (refractive index 1). It has become.

  The protection member 30 is transparent to the measurement light 102 and is laminated on the incident side end 20a and the emission side end 20b of the measurement light in the laminated unit 20, respectively, and is incident side end 20a and emission side end. It is a flat plate-like member that protects 20b (surface 21a that is the outermost surface in the stacking direction). In the present embodiment, a glass protective member 30 made of the same material as the transparent substrate 21 is laminated on the incident side end 20a and the emission side end 20b of the measurement light in the laminated unit 20 via the spacer 24. ing. Further, an antireflection film 31 similar to the antireflection film 22 is provided on both surfaces (transmission surfaces) of the protective member 30.

  The holder 40 holds the transparent base material 21 having the standard particles 23 fixed on the surface 21a through the antireflection film 22 in a state where a plurality of the alternating base materials are alternately laminated with the spacers 24, and as an integrated laminated unit 20 The holding member corresponds to the holding member described in the claims. In the present embodiment, the holder 40 is configured so as to hold the protective member 30 together with the laminated unit 20 and hold them together.

  Specifically, the laminated unit 20 and the protection member 30 that are laminated in a state in which the holder 40 is integrated with a cylindrical outer peripheral part 41 that surrounds the outer periphery of the laminated unit 20 and the outer peripheral part 41 by screw fastening or the like. Is provided with an annular incident side clamping part 42 and an emission side clamping part 43 that are clamped from both ends in the stacking direction. The cylindrical outer peripheral portion 41 has an inner peripheral surface substantially coincident with the outer peripheral shape of the laminated unit 20, and the size thereof is substantially the same as or slightly larger than the outer periphery of the laminated unit 20 (in the example shown in FIG. 2, it is slightly larger). ). In addition, the annular incident side clamping portion 42 is in contact with the end face of the corresponding protection member 30 and the peripheral portion of the incident side surface, and the annular emission side clamping portion 43 is the outer peripheral surface and the emission side of the corresponding protection member 30. It touches the periphery on the surface. The inner peripheral surface of the incident-side sandwiching portion 42 is an incident-side opening wall portion 44 in the holder 40, and the inner peripheral surface of the emitting-side sandwiching portion 43 is an exit-side opening wall portion 45 in the holder 40. That is, the measurement light 102 is irradiated to the laminated unit 20 through the opening surrounded by the incident-side opening wall 44, and the transmitted light is radiated to the outside through the opening surrounded by the emission-side opening wall 45. It has become.

  Next, a method for manufacturing the calibration device 10 will be described. First, as shown in FIG. 1, the particle size distribution measurement of the measurement object 100 at the width L portion is performed by the optical measurement device. At this time, in the stacking direction (the optical axis direction of the measurement light 102), by imaging at a plurality of points while changing the focal position of the imaging device 103, the distance (focal point) from the focused particle 100a to the end on the incident side. Two-dimensional data of the dispersion state (particle size distribution, number per unit area, and average particle interval) of the particles 100a for each position) is acquired. Moreover, the data of the average particle | grain space | interval in the lamination direction according to the distance from an incident side edge part are acquired.

  Then, based on the obtained two-dimensional data of the dispersion state, the diameter (a mixture of one kind or plural kinds) and the number of sample particles (beads) such as a sphere and an ellipse (sphere) adopted as the standard particle 23 (Mixing ratio) is determined. Further, in the stacking direction, the average particle spacing of the adjacent standard particles 23 fixed to the different surfaces 21a is substantially matched with the data of the average particle spacing in the stacking direction obtained at the corresponding position in the measurement object 100. The thickness of the transparent substrate 21 including the antireflection film 22 and the thickness of the spacer 24 are determined according to the distance from the incident side end.

  Next, spraying with an air brush or the like, or using a known dry dispersion unit (specifically, a dry dispersion unit manufactured by MALVERN), a predetermined dispersion state (per unit area) in the imaging area of the surface 21a of the transparent substrate 21 is used. The standard particles 23 are arranged on the surface 21a of the transparent substrate 21 provided with the antireflection film 22 so that the number of the particles and the distance between the particles can be reduced. For example, in the case of an airbrush, the number per unit area and the average interparticle distance can be changed according to the spraying pressure.

  In the present embodiment, when the standard particles 23 are arranged on the surface 21a (antireflection film 22) of the transparent substrate 21, the standard particles 23 are heated while being heated to such an extent that only the surface of the standard particles 23 is melted (softened). 23 is disposed on the transparent substrate 21. Therefore, the standard particles 23 are welded and fixed while being arranged on the transparent substrate 21 (antireflection film 22).

  After fixing the standard particles 23, each transparent substrate 21 on which the standard particles 23 are fixed is optically measured with a microscope or the like, and the dispersion state (particle size distribution, number per unit area) of the standard particles 23 on the fixed surface 21a. , Average particle spacing) is determined whether or not the dispersion state of the particles 100a in the corresponding cross section of the measurement object 100 substantially matches. And the thing in which a dispersion state substantially corresponds is selected, and it is set as the transparent base material 21 of the predetermined position which comprises the lamination | stacking unit 20. FIG.

  Then, the selected transparent base materials 21 are alternately laminated with the spacers 24 to form the laminated unit 20, and the spacers are placed on the incident side end 20 a and the emission side end 20 b of the measurement light 102 in the laminated unit 20. The protective member 30 is laminated via the 24. These stacked states are held by the holder 40. As described above, the calibration device 10 is formed by laminating a plurality of transparent base materials 21 on which the standard particles 23 are fixed.

  Next, a method for calibrating the optical measuring apparatus using the calibration apparatus 10 will be described. FIG. 5 is a schematic diagram for explaining the calibration method. In FIG. 5, for convenience, only the stacked unit of the calibration apparatus is illustrated.

  In a state where the calibration device 10 is irradiated with the measurement light 102 from the light source of the optical measurement device, an image is taken by focusing the imaging device 103 on, for example, the nth transparent substrate 21 from the light irradiation side in the stacked unit 20. In the photographed image, the focused standard particle 23 and the out-of-focus blurred standard particle 23 are photographed. Since the focused standard particle 23 is the standard particle 23 fixed to the nth transparent substrate 21 measured in advance with a microscope or the like before lamination, an image obtained by photographing the nth transparent substrate 21 before lamination. For example, the binarization level is calibrated so that the positions and particle diameters of the standard particles 23 in FIG. In this way, the optical measuring device can be calibrated. In the above example, the transparent substrate 21 is the focal position, but one of the two surfaces 21a of the transparent substrate 21 may be the focal position.

  Next, the effect of the calibration apparatus 10 having the above configuration will be described. As described above, in this embodiment, the dispersion state of the standard particles 23 fixed to each surface 21a of the transparent substrate 21 is substantially the same as the dispersion state of the particles 100a in the cross section at the corresponding position in the measurement object 100. Have been matched. And the calibration apparatus 10 (lamination | stacking unit 20) is comprised by laminating | stacking the transparent base material 21 with which the standard particle 23 was fixed to the surface 21a in a multilayer along the optical axis of the measurement light 102. FIG. Therefore, in the stacking direction, the standard particles 23 on the surface 21a of the transparent substrate 21 that is the focal position, regardless of which surface 21a of the plurality of transparent substrates 21 constituting the calibration device 10 is the focal position of the imaging device 103. This dispersion state substantially coincides with the dispersion state of the particles 100a in the cross section of the corresponding position in the measurement object 100.

  Further, in the stacking direction, the distance between the incident-side end 20a and the exit-side end 20b of the stacked unit 20 is substantially the same as the length L of the optical path length of the measuring light 102 in the measured object 100. The standard particles 23 are fixed to both surfaces 21 a of each transparent base material 21, and the thickness of the transparent base material 21 including the antireflection film 22 and the thickness of the spacer 24 in the stacking direction are the same as the measured object 100. It is substantially the same as the average particle interval at the corresponding position.

  As described above, in this embodiment, the standard particles 23 are three-dimensionally arranged in a state closer to the dispersion state (three-dimensional dispersion state) of the particles 100a in the measurement object 100. Therefore, if the above-described calibration device 10 is used, the multiple scattering at the measurement object 100 can be reproduced, and thus the optical measurement device that measures the particle size distribution of the measurement object 100 arranged three-dimensionally can be obtained with high accuracy. Can be calibrated well.

  In the present embodiment, the antireflection film 22 is provided on both surfaces 21 a of the transparent substrate 21. Therefore, although it is the structure which laminated | stacked the transparent base material 21 in the multilayer, reflection on the surface 21a is suppressed and the transmitted light amount can be ensured. The antireflection film 22 can suppress ghosts and flares due to repetitive reflection (suppress reduction in image contrast), and can further improve the accuracy of calibration.

  Moreover, in this embodiment, the standard particle 23 consists of resin, and is being fixed with respect to the transparent base material 21 by the welding of the surface. Thus, when resin standard particles 23 having a melting point temperature lower than that of the transparent base material 21 are employed, the standard particles 23 are secured to the transparent base material while ensuring the particle shape without requiring an adhesive or the like separately. Since it can be fixed (welded), it is optically preferable.

  In the present embodiment, the standard particles 23 are fixed to both surfaces 21a of each transparent substrate 21, and the thickness of the transparent substrate 21 including the antireflection film 22 and the thickness of the spacer 24 are determined by the measured object. The average particle spacing at the corresponding position in 100 is approximately the same. Thus, when it is set as the structure where the standard particle 23 was fixed to both the surfaces 21a of the transparent base material 21, if the average particle | grain space | interval is the same, compared with the structure where the standard particle 23 is fixed only to one surface 21a. The thickness of the transparent base material 21 and the spacer 24 can be increased. In particular, as the thickness of the transparent base material 21 decreases, the flatness decreases due to the mechanical processing characteristics (polishing characteristics) (the central portion is depressed more than the peripheral portion), and thus the image is distorted. Although it becomes easy, according to the above, such distortion can be made difficult to occur.

  Further, in the present embodiment, a plurality of transparent base materials 21 are sandwiched by the holders 40 (the sandwiching portions 42 and 43) from both ends 20a and 20b in the stacking direction in a state of being stacked on each other via the spacer 24. Thus, a plurality of transparent base materials 21 are integrated to form a laminated unit 20. Therefore, it is possible to easily replace only a part of the plurality of transparent base materials 21.

(Second Embodiment)
Next, 2nd Embodiment of this invention is described based on FIGS. FIG. 6 is a cross-sectional view illustrating a schematic configuration of a stacked unit that is a main characteristic portion of the calibration apparatus according to the second embodiment.

  Since the calibration apparatus according to the second embodiment is often in common with that according to the first embodiment, the detailed description of the common parts will be omitted below, and the different parts will be described mainly. In addition, the same code | symbol shall be provided to the element same as the element shown in 1st Embodiment.

  In the first embodiment, an example in which the reflection light 22 on the surface 21a is prevented from being reflected by providing the antireflection film 22 on the surface 21a of the transparent base material 21 and the transmitted light amount is secured while having a multilayer structure is shown. . On the other hand, in the present embodiment, as shown in FIG. 6, a filler that is transparent to the measurement light 102 in the region between the opposing surfaces 21 a of the transparent base materials 21 that are adjacent to each other via the spacer 24. 26, and this filler 26 is characterized in that the reflection on the surface 21a is reduced.

  In the example shown in FIG. 6, the antireflection film 22 on the surface 21 a of the transparent base material 21 is not provided, and the resin standard particles 23 are directly fixed to the transparent base material 21 by melting of the surface. ing. In addition, the thickness of the transparent substrate 21 is substantially matched with the average particle spacing at the corresponding position in the measurement object 100. Other configurations are the same as those in the first embodiment.

  Also in the present embodiment, similarly to the first embodiment, a crown glass having a refractive index of 1.524 is adopted as a constituent material of the transparent substrate 21, and a crosslinked polystyrene having a refractive index of 1.59 is used as a constituent material of the standard particles 23. Adopted. As a constituent material of the filler 26, ion-exchanged water (refractive index 1. 33) is adopted.

  As described above, also in this embodiment, the standard particles 23 are in a state closer to the dispersed state of the particles 100a in the three-dimensionally arranged measurement object 100, similarly to the calibration device 10 (laminated unit 20) shown in the first embodiment. Are arranged three-dimensionally. Therefore, if the calibration apparatus 10 according to the present embodiment is used, the multiple scattering in the measurement object 100 can be reproduced, and thereby the optical measurement apparatus that measures the particle size distribution of the measurement object 100 arranged three-dimensionally. Can be calibrated with high accuracy.

  In this embodiment, the refractive index of the standard particles 23 is larger than the refractive index of the transparent substrate 21 and the refractive index of the filler 26. That is, standard particles 23 (refractive index 1.59) having a higher refractive index are three-dimensionally arranged in a medium having a lower refractive index. As a result, the measurement object 100 in which fuel fine particles 100a (n-heptane with a refractive index of 1.3886) are three-dimensionally arranged in air (refractive index 1) is obtained. And in such a calibration apparatus 10, it is transparent with respect to the measurement light 102 in the area | region between the surface 21a which the adjacent transparent base material 21 opposes, a refractive index is smaller than a transparent base material, and refractive index is more than air. A large filler 26 is filled. Therefore, since the difference in refractive index between two adjacent media is smaller than the configuration in which air (refractive index 1) is adjacent to the surface 21a of the transparent base material 21, the reflection on the surface 21a of the transparent base material 21 is reduced. The amount of transmitted light can be secured while the transparent substrate 21 is laminated in multiple layers. In addition, it is possible to suppress the deterioration of the contrast of the image due to repetitive reflection and to further improve the calibration accuracy.

  In addition, as shown in the first embodiment, when the antireflection film 22 is provided on the surface 21a of the transparent substrate 21, the antireflection film 22 is generally provided by a vapor deposition method. It will be influenced by the flatness of the material 21, and as the thickness of the transparent substrate 21 is reduced, the image is more likely to be distorted. On the other hand, in this embodiment, since the filler 26 is filled between the opposing surfaces 21a of the adjacent transparent base materials 21 without a gap, such distortion can be reduced.

  In addition, it is not specifically limited as a method of filling the filler 26 between the opposing surfaces 21a of the adjacent transparent base materials 21 without a gap. As an example, in this embodiment, as shown in FIGS. 7 and 8, the spacer 24 is substantially C-shaped, and an opening between the C-shaped end portions of the spacer 24 is formed in the outer peripheral portion 41 constituting the holder 40. An air vent hole 41a communicating with the region between the opposing surfaces 21a of the adjacent transparent base materials 21 is provided through the portion. Then, the calibration device 10 is immersed in the filler 26 with the air vent hole 41a facing up before the air vent hole 41a is blocked by the stopper plug 46, and the air vent hole 41a is stopped in the air vent hole 41a. The calibration device 10 is formed by plugging the stopper 46. In addition, the code | symbol 47 shown in FIG. 7 is a gasket for sealing. Further, the filler 26 is also filled between the end portion of the laminated unit 20 and the protective member 30, and the antireflection film 31 is provided only on the back surface of the protective member 30 facing the laminated unit 20. . FIG. 7 is a cross-sectional view showing a schematic configuration of the calibration apparatus. 8 is a cross-sectional view taken along line VIII-VIII shown in FIG.

  Note that when the refractive index of the filler 26 is substantially matched with the refractive index of the transparent base material 21, reflection on the surface 21a of the transparent base material 21 can be almost eliminated. However, as shown in the present embodiment, when the refractive index (1.59) of the standard particles 23 is larger than the refractive index (1.524) of the transparent substrate 21, but both are close to each other, the filler When a so-called index matching oil (for example, silicon oil having a refractive index of 1.52) having substantially the same refractive index as that of the transparent base material 21 is used as 26, the difference in refractive index between the standard particles 23 and the filler 26 is reduced. That is, the angle at which the measurement light 102 transmitted through the filler 26 is refracted by the standard particles 23 becomes small. Therefore, as the number of transparent substrates 21 increases, as shown in FIG. 9A, the contrast of the standard particles 23 on the image becomes the image of the measured object 100 shown in FIG. Compared to (contrast). In this case, since the accuracy must be verified at a binarization level different from that when measuring the particle size distribution of the measurement object 100, the calibration device 10 is not preferable. On the other hand, in the present embodiment, as described above, the constituent material of the filler 26 is transparent to the measurement light 102, is smaller than the refractive index of the transparent substrate 21, and is larger than the refractive index 1 of air. A material having a refractive index is employed. Therefore, even if the refractive indexes of the transparent base material 21 and the standard particles 23 are close to each other, the decrease in contrast of the standard particles 23 is suppressed as shown in FIG. It can be set to the same level as the image of the measurement object 100 (contrast of the particles 100a). FIG. 9 is a diagram schematically showing an image taken by an optical measuring device, where (a) is an image when the refractive index of the filler is substantially matched with the transparent substrate, and (b) is a filler. (C) shows an image of the object to be measured as a reference example.

  In the present embodiment, an example of the calibration apparatus 10 simulating the measurement target 100 in which the refractive index of the particle 100a is larger than the refractive index of the surrounding medium is shown. However, the refractive index of the standard particle 23 is smaller than the refractive index of the transparent substrate 21 and the refractive index of the filler 26, that is, the measured object 100 in which the refractive index of the particle 100a is smaller than the refractive index of the surrounding medium. The present invention can also be applied to the calibration device 10 that simulates (for example, a measured object in which particles such as bubbles in the liquid appear bright). The filler 26 is made of a material having a refractive index larger than that of the transparent base material 21 and having a refractive index smaller than that of the transparent base material 21 and air. Can be adopted. According to this, since the difference in refractive index between two adjacent media is smaller than the configuration in which air (refractive index 1) is adjacent to the surface 21a of the transparent base material 21, reflection on the surface 21a of the transparent base material 21 is prevented. The amount of transmitted light can be secured while the transparent base material 21 is laminated in multiple layers. In addition, it is possible to suppress the deterioration of the contrast of the image due to repetitive reflection and to further improve the calibration accuracy. Furthermore, since the refractive index of the filler 26 is larger than that of the transparent base material 21, even if the refractive index of the transparent base material 21 and the standard particles 23 are close to each other, it is possible to suppress a decrease in image contrast.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 10 is a cross-sectional view illustrating a schematic configuration of a stacked unit which is a main characteristic portion of the calibration apparatus according to the third embodiment. In addition, in FIG. 10, the protection member laminated | stacked with the lamination | stacking unit is also shown in figure.

  Since the calibration apparatus according to the third embodiment is in common with those according to the above-described embodiments, detailed description of the common parts will be omitted below, and different parts will be described mainly. In addition, the same code | symbol shall be provided to the element same as the element shown to each embodiment.

  In the second embodiment, although the refractive index (1.59) of the standard particles 23 is larger than the refractive index (1.524) of the transparent base material 21, both values are close to each other and are different from the transparent base material 21. The example in which the filler 26 having a ratio is filled in the region between the opposing surfaces 21 a of the adjacent transparent base materials 21 via the spacers 24 is shown. On the other hand, in this embodiment, as shown in FIG. 10, the refractive index of the standard particles 23 is different from the refractive index of the transparent base material 21, and the opposite surface 21 a of the adjacent transparent base material 21 through the spacer 24. It is characterized in that the refractive index of the filler 27 filled in the region between them is substantially the same as the refractive index of the transparent substrate 21.

  In the present embodiment, as in the first embodiment, the measurement object 100 (particle 100a is shown as a shadow) in which fuel fine particles 100a (n-heptane with a refractive index of 1.3876) are three-dimensionally arranged in air (refractive index 1). The configuration is similar to that of the configuration. Specifically, quartz (refractive index: 1.46) is used as a constituent material of the transparent base material 21, titanium barium-based glass (refractive index: 1.93) manufactured by Unitika is used as a constituent material of the standard particles 23, and constituent materials of the filler 27. A refractive index matching liquid (refractive index: 1.46) manufactured by Moritec is used. Further, in order to fix the standard particles 23 made of glass to the surface 21a of the transparent base material 21 made of quartz, an adhesive layer 28 (refractive index 1) made of an ultraviolet curable resin made of NTTAT is formed on both surfaces 21a of the transparent base material 21. .46). Then, by irradiating with ultraviolet rays in a state where the standard particles 23 are arranged on the adhesive layer 28 provided on the surface 21a of the transparent substrate 21, the transparent substrate 21 to which the standard particles 23 are fixed is obtained. ing. Note that the thickness of the transparent substrate 21 including the adhesive layer 28 is substantially matched with the average particle spacing at corresponding positions in the measurement object 100. The structure of the other lamination | stacking unit 20 is the same as 1st Embodiment. Further, a filler 27 is also filled between the end portion of the laminated unit 20 and the protective member 30, and the antireflection film 31 is provided only on the back surface of the protective member 30 facing the laminated unit 20. .

  As described above, also in this embodiment, the standard particles 23 are in a state closer to the dispersed state of the particles 100a in the three-dimensionally arranged measurement object 100, similarly to the calibration device 10 (laminated unit 20) shown in the first embodiment. Are arranged three-dimensionally. Therefore, if the calibration apparatus 10 according to the present embodiment is used, the multiple scattering in the measurement object 100 can be reproduced, and thereby the optical measurement apparatus that measures the particle size distribution of the measurement object 100 arranged three-dimensionally. Can be calibrated with high accuracy.

  In the present embodiment, the refractive index of the transparent base material 21, the refractive index of the filler 27, and the refractive index of the adhesive layer 28 are substantially the same, whereby a uniform medium (transparent member) having almost no refractive index distribution. Inside, the standard particles 23 are three-dimensionally arranged. Therefore, the calibration apparatus 10 is in a state closer to the state of the measured object 100 in which the particles 100a appear as shadows, such as fuel fine particles injected into the air, and thereby the calibration accuracy can be further improved. Moreover, in this embodiment, since the reflection by the surface 21a of the transparent base material 21 hardly arises, this can ensure the amount of transmitted light. Further, it is possible to suppress a decrease in the contrast of the image due to repeated reflection, and to further improve the accuracy of calibration.

  In particular, in the present embodiment, materials having a refractive index of 1.46 are employed as the transparent base material 21, the filler 27, and the adhesive layer 28, respectively, and glass having a refractive index of 1.93 is employed as the standard particles 23. . Thus, the standard particles 23 (refractive index 1.93) are three-dimensionally arranged in a uniform medium (refractive index 1.46) having almost no refractive index distribution. Here, the ratio of the refractive index of the standard particle 23 to the medium is 1.322, which is substantially the same value as the ratio of the refractive index of the fuel fine particles 100a (n-heptane) to the medium air, which is 1.3876. Therefore, the calibration apparatus 10 shown in the present embodiment is particularly suitable for calibrating an optical measurement apparatus that measures the particle size distribution of the measurement target 100 that is an aggregate of the fuel fine particles 100a.

  Also in the present embodiment, the reflection on the transparent base material 21 is reduced by filling the filler 27 between the opposing surfaces 21a of the adjacent transparent base materials 21 without any gaps. Accordingly, as in the second embodiment, image distortion due to the flatness of the transparent substrate 21 can be reduced.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not restrict | limited at all to the embodiment mentioned above, the main point of this invention (The transparent base material 21 by which the standard particle 23 was fixed to the surface 21a is made several sheets. Various modifications can be made without departing from the laminated calibration apparatus 10).

  In 1st Embodiment, the antireflection film 22 is provided in both the surfaces 21a of the transparent base material 21, and the resin-made standard particle 23 is fixed on the antireflection film 22 of both surfaces 21a by welding. It was. However, a configuration in which the antireflection film 22 is provided only on one surface 21a of the transparent substrate 21 may be employed. Further, the standard particles 23 may be directly fixed to the surface 21a of the transparent substrate 21 (the back surface of the surface 21a provided with the antireflection film 22). When the standard particles 23 are directly fixed to the surface 21 a of the transparent base material 21, a resin is used as a constituent material of the transparent base material 21, and a material having a melting point higher than that of the transparent base material 21 as a constituent material of the standard particles 23. It is good also as a structure which employ | adopted (for example, glass), fuse | melted the surface (including the surface 21a) of the transparent base material 21 by heating, and the standard particle 23 was fixed.

  In the first embodiment, an example in which the refractive index of the standard particles 23 is larger than the refractive index of the transparent substrate 21 has been shown. However, in the case of the calibration apparatus 10 simulating the object to be measured 100 in which the refractive index of the particle 100a is smaller than the refractive index of the medium around the particle 100a, the standard particle 23 has a refractive index higher than that of the transparent substrate 21. Small materials can be used.

  In 2nd Embodiment, the example which the resin-made standard particle 23 is directly fixed to the surface 21a of the transparent base material 21 by welding was shown. However, the structure for fixing the standard particles 23 to the surface 21a of the transparent substrate 21 is not limited to the above example. For example, as described above, resin is used as the constituent material of the transparent base material 21, and a material (for example, glass) having a melting point higher than that of the transparent base material 21 is used as the constituent material of the standard particles 23. The surface (including the surface 21a) may be melted to fix the standard particles 23. Alternatively, an adhesive layer 28 having a refractive index substantially identical to that of the transparent substrate 21 may be provided on the surface 21 a of the transparent substrate 21, and the standard particles 23 may be fixed to the transparent substrate 21 via the adhesive layer 28. Furthermore, as shown in the first embodiment, an antireflection film 22 may be provided on the surface 21 a of the transparent substrate 21 and the standard particles 23 may be fixed via the antireflection film 22. In this case, the reflection on the surface 21 a of the transparent substrate 21 can be further reduced by the effects of the antireflection film 22 and the filler 26.

  In the third embodiment, an adhesive layer 28 whose refractive index substantially matches the transparent base material 21 is provided on the surface 21 a of the transparent base material 21, and the standard particles 23 are fixed to the transparent base material 21 via the adhesive layer 28. An example is shown. However, depending on the ratio of the refractive index of the particle 100a to the medium in the object to be measured 100, a structure in which the transparent base material 21 and the standard particle 23 are directly fixed can be used.

FIG. 1 is a diagram showing a schematic configuration of particle size distribution measurement by an optical measurement device for a measurement object. It is sectional drawing which shows schematic structure of the calibration apparatus which concerns on 1st Embodiment. It is sectional drawing which follows the III-III line | wire shown in FIG. It is sectional drawing which shows schematic structure of the lamination | stacking unit which is a main characteristic part among the calibration apparatuses shown in FIG. It is a schematic diagram for demonstrating the calibration method. It is sectional drawing which shows schematic structure of the lamination | stacking unit which is a main characteristic part among the calibration apparatuses which concern on 2nd Embodiment. It is sectional drawing which shows schematic structure of a calibration apparatus. It is sectional drawing which follows the VIII-VIII line shown in FIG. It is the figure which showed typically the image image | photographed with the optical measuring device, (a) is an image at the time of making the refractive index of a filler substantially correspond with a transparent base material, (b) is the refractive index of a filler. An image in the case of being smaller than the transparent substrate and larger than 1, (c) shows an image of the measured object as a reference example. It is sectional drawing which shows schematic structure of the lamination | stacking unit which is a main characteristic part among the calibration apparatuses which concern on 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Calibration apparatus 20 ... Laminating unit 21 ... Transparent base material 21a ... Surface 22 ... Antireflection film 23 ... Standard particle 24 ... Spacer 25 ... Air 26, 27 ... Filler 100 ... Measurement object 100a ... Fuel fine particles (particles)
101 ... Injector 102 ... Measurement light 103 ... Imaging device

Claims (10)

A calibration device for calibrating an optical measurement device that measures the particle size distribution of a three-dimensionally arranged object to be measured,
A plurality of flat transparent substrates that are transparent to the measurement light of the optical measurement device and are provided with antireflection films on at least one of both surfaces through which the measurement light is transmitted;
It has a refractive index different from that of the transparent substrate and a transmittance that substantially matches the object to be measured, and is fixed to at least one of both surfaces of each transparent substrate directly or via the antireflection film. Standard particles,
A spacer that is alternately laminated with the transparent base material in the optical axis direction of the measurement light, and that keeps the surfaces of the transparent base materials through which the measurement light is transmitted substantially parallel to each other,
In the plurality of transparent substrates stacked via the spacer, the distance between the measurement light incident side end and the output side end is substantially the same as the optical path length of the measurement light in the measurement object. And
The standard particles fixed on the same surface of the transparent substrate, the particle size distribution, the number per unit area, and the average particle interval in the cross section corresponding to the same position of the measured object, the particle size distribution, It is approximately the same as the number per unit area and the average particle spacing,
In the laminating direction, the antireflection film so that the distance between the surfaces of the transparent base material to which the standard particles adjacent to each other are fixed substantially coincides with the average particle spacing at the corresponding position in the measurement object. A calibration apparatus characterized in that the thickness of the transparent base material including the thickness of each of the spacers is set.   The calibration apparatus according to claim 1, wherein the standard particles are made of a resin and are fixed to the transparent base material by welding of the surfaces thereof. The standard particles are fixed to both surfaces of each transparent substrate,
The thickness of the transparent base material including the antireflection film and the thickness of the spacer are substantially the same as the average particle spacing at corresponding positions in the measured object. The calibration device described in 1. A calibration device for calibrating an optical measurement device that measures the particle size distribution of a three-dimensionally arranged object to be measured,
A plurality of flat transparent substrates transparent to the measuring light of the optical measuring device and having a refractive index n1,
It has a refractive index n2 different from the refractive index n1 and a transmittance that substantially matches the measured object, and is fixed to at least one of both surfaces of each transparent substrate through which the measurement light is transmitted Standard particles,
Alternatingly stacked in the optical axis direction of the measurement light alternately with the transparent base material, and a spacer that keeps the surfaces of the transparent base materials through which the measurement light is transmitted substantially parallel to each other;
A filler filled in a region between opposing surfaces of the transparent bases adjacent via the spacer, transparent to the measurement light, and having a refractive index n3 that substantially matches the refractive index n1. ,
In the plurality of transparent substrates stacked via the spacer, the distance between the measurement light incident side end and the output side end is substantially the same as the optical path length of the measurement light in the measurement object. And
The standard particles fixed on the same surface of the transparent substrate, the particle size distribution, the number per unit area, and the average particle interval in the cross section corresponding to the same position of the measured object, the particle size distribution, It is approximately the same as the number per unit area and the average particle spacing,
In the stacking direction, the transparent substrate so that the distance between the surfaces of the transparent substrate on which the standard particles adjacent to each other are fixed substantially coincides with the average particle interval at the corresponding position in the measured object. And a thickness of each of the spacers are set. A calibration device for calibrating an optical measurement device that measures the particle size distribution of a three-dimensionally arranged object to be measured,
A plurality of flat transparent substrates transparent to the measuring light of the optical measuring device and having a refractive index n1,
It has a refractive index n2 larger than the refractive index n1 and a transmittance that substantially matches the measured object, and is fixed to at least one of both surfaces of each transparent substrate through which the measurement light is transmitted Standard particles,
Alternatingly stacked in the optical axis direction of the measurement light alternately with the transparent base material, and a spacer that keeps the surfaces of the transparent base materials through which the measurement light is transmitted substantially parallel to each other;
Filled in a region between the opposing surfaces of the transparent bases adjacent via the spacer, transparent to the measuring light, and having a refractive index n3 smaller than the refractive index n1 and larger than the refractive index 1 With materials,
In the plurality of transparent substrates stacked via the spacer, the distance between the measurement light incident side end and the output side end is substantially the same as the optical path length of the measurement light in the measurement object. And
The standard particles fixed on the same surface of the transparent substrate, the particle size distribution, the number per unit area, and the average particle interval in the cross section corresponding to the same position of the measured object, the particle size distribution, It is approximately the same as the number per unit area and the average particle spacing,
In the stacking direction, the transparent substrate so that the distance between the surfaces of the transparent substrate on which the standard particles adjacent to each other are fixed substantially coincides with the average particle interval at the corresponding position in the measured object. And a thickness of each of the spacers are set. A calibration device for calibrating an optical measurement device that measures the particle size distribution of a three-dimensionally arranged object to be measured,
A plurality of flat transparent substrates transparent to the measuring light of the optical measuring device and having a refractive index n1,
It has a refractive index n2 smaller than the refractive index n1 and a transmittance substantially equal to the measured object, and is fixed to at least one of both surfaces of each transparent substrate through which the measurement light is transmitted Standard particles,
Alternatingly stacked in the optical axis direction of the measurement light alternately with the transparent base material, and a spacer that keeps the surfaces of the transparent base materials through which the measurement light is transmitted substantially parallel to each other;
A region between the opposing surfaces of the transparent bases adjacent to each other through the spacer is filled, transparent to the measurement light, larger than the refractive index n1, and a difference from the refractive index n1 is a refractive index n1. And a filler having a refractive index n3 smaller than the difference between refractive index 1 and
In the plurality of transparent substrates stacked via the spacer, the distance between the measurement light incident side end and the output side end is substantially the same as the optical path length of the measurement light in the measurement object. And
The standard particles fixed on the same surface of the transparent substrate, the particle size distribution, the number per unit area, and the average particle interval in the cross section corresponding to the same position of the measured object, the particle size distribution, It is approximately the same as the number per unit area and the average particle spacing,
In the stacking direction, the transparent substrate so that the distance between the surfaces of the transparent substrate on which the standard particles adjacent to each other are fixed substantially coincides with the average particle interval at the corresponding position in the measured object. And a thickness of each of the spacers are set.   The calibration apparatus according to any one of claims 4 to 6, wherein the standard particles are made of resin and fixed to the transparent base material by welding of the surfaces thereof. A refractive index n4 substantially equal to the refractive index n1, further comprising an adhesive layer made of an ultraviolet curable resin provided on at least one of both surfaces of the transparent substrate;
The calibration apparatus according to claim 4, wherein the standard particles are bonded and fixed to the adhesive layer in each transparent substrate. The standard particles are fixed to both surfaces of each transparent substrate,
The thickness of the transparent base material and the thickness of the spacer are approximately the same as the average particle spacing at corresponding positions in the measured object. Calibration equipment.   A plurality of said transparent base materials are clamped by the holding member from the both ends in the lamination direction in a state of being laminated with each other via the spacer, and are integrated. The calibration device according to item.

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