JP6010009B2 - ATR element and immersion probe - Google Patents

Description

  The present invention relates to an immersion probe suitable for measuring, for example, a concentration change of a reactive group of a synthetic resin, and more particularly to an ATR element.

  In the process of producing a synthetic resin such as polyurethane and polyester, in order to grasp the progress of the reaction, the change in the concentration of the reactive group (for example, -NCO, -OH, -COOH) contained in the reaction liquid to be measured is measured. It is required to measure accurately in-line.

  Conventionally, an immersion probe comprising a sensing element immersed in a reaction solution, an irradiation optical fiber that irradiates the sensing element with measurement light, and a light receiving optical fiber that receives the measurement light that has passed through the measurement target has been provided. Known (for example, Patent Document 1). This immersion probe is provided with a gap portion in which the measurement object is filled in the sensing element, and the measurement light transmitted through the measurement object filled in the gap portion is received by the light receiving optical fiber. Since part of the wavelength component is absorbed when the measurement light passes through the measurement target in the gap, the concentration of the reactive group can be measured by analyzing the measurement light received by the light receiving optical fiber. However, since the reaction liquid is agitated in the chemical reaction tank, the reaction liquid mixed with air bubbles accompanying the agitation may be filled in the voids. It becomes difficult to measure the correct concentration.

  Here, an ATR method (Attenuated Total Reflection) is known as one of methods for analyzing and measuring substances. An immersion probe to which this ATR method is applied is also known (for example, Patent Document 2).

  The summary of the analysis by the ATR method is as follows. A measurement object is brought into close contact with an ATR element (typically a crystal) having a large refractive index, the incident angle of measurement light is set to be larger than the critical angle, and total reflection occurs between the measurement object and the ATR substance. When total reflection occurs, light is reflected from the measurement object and the ATR element at the interface after being slightly swept to the measurement object side. This reflected light is called evanescent light. In the region where the measurement light is absorbed in the measurement object, the energy of the reflected light at the wavelength specific to the measurement object decreases according to the intensity of the absorption. The substance can be analyzed and measured by measuring the spectrum of the reflected light.

JP 2009-250825 A JP 2004-85433 A

Assuming that the concentration of the reactive group of the synthetic resin is measured, the distance from the reaction vessel containing the reaction solution in which the immersion probe is immersed to the spectrophotometer to which the measurement result is transmitted may be considerably separated. Since this interval is connected by an optical fiber, the wavelength of the measurement light irradiated to the immersion probe becomes a problem.
In consideration of accurately measuring the concentration of the reactive group, for example, it is recommended to use measurement light in a wavelength range of 2500 nm or more. However, since light in this wavelength range has a large attenuation in the optical fiber, It is difficult to put it to practical use. On the other hand, light in the near infrared region having a wavelength of 1000 to 2000 nm has a small attenuation in the optical fiber, and there is no problem of light guide by the optical fiber. However, the light in the near infrared region has an extremely small absorption coefficient in the reactive group, so it is difficult to accurately measure the concentration of the reactive group.
The present invention has been made based on the above technical problem, and uses a measurement light in the near infrared region, which is easy to guide with an optical fiber, and has a small absorption coefficient for the measurement light. Another object of the present invention is to provide an ATR element capable of accurately specifying the state of a substance.

When measuring a substance with a small absorption coefficient, increase the number of reflections as much as possible to increase the total amount of light absorbed by the measurement object from when the measurement light enters the probe until it is emitted. It is desirable.
As a probe to which the ATR method is applied, in addition to a single reflection type with one reflection, a multiple reflection type with a plurality of reflections is known. However, the ATR element of the trapezoidal multi-reflection probe known so far has a number of reflections of about 20, so that it is still insufficient for the measurement object intended by the present invention.

Therefore, the present inventors have studied an ATR element that can realize an immersion probe that can obtain a significantly higher number of reflections than before. As a result, the ATR element having a reflection surface on the side surface continuous in the circumferential direction is used, and the measurement light is continuously reflected on the reflection surface to effectively utilize the evanescent light, thereby surpassing the conventional multiple reflection. It was found that the number of reflections would be obtained.
The ATR element of the present invention is based on this finding, is composed of an axially symmetric solid, has an element body having a reflection surface that is continuous in the circumferential direction, and a pair of end faces that are opposed to each other in the axial direction; An incident portion that is incident, and an emission portion that is incident from the incident portion and is reflected by the reflecting surface of the element body, and is emitted to the outside, and the measuring light incident from the incident portion is reflected by the reflecting surface. An ATR element that repeats a spiral passage and is emitted outward from the emitting part, and the incident part and the emitting part are disposed on one of a pair of end faces of the element body. It is characterized by that.

According to the ATR element of the present invention, the measurement light incident on the incident part repeats reflection inside the ATR element and follows the forward path and the return path before reaching the emission part. That is, the measurement light incident from the incident part follows the spiral passage route while being repeatedly reflected on the reflection surface (side surface continuous in the circumferential direction) and reaches the other end surface facing the spiral. This is the outbound path. When the measurement light that has reached the other end face is reflected by the end face, it repeats reflection at the reflection face, follows the spiral passage, reaches the exit section provided on the end face on the incident side, and from there to the outside Is emitted. This is the return trip.
As described above, the ATR element of the present invention can repeat reflection in each of the forward path and the return path, and thus realizes the number of reflections that cannot be obtained by the conventional multiple reflection type ATR element.

In the ATR element of the present invention, since the measurement light repeats reflection on the reflecting surface and follows a spiral passage path, the incident portion is referenced from the symmetry axis in the reference cross section x orthogonal to the symmetry axis of the element body. more than 80% of the distance to the outer periphery of the cross section x, be in a position of less than 100% (condition a), and, that forms a reference plane x and 45 degrees from (condition B) is obtained.
Condition A is exclusively required to increase the number of times the measurement light is reflected.
Condition B is required exclusively for the measurement light to follow the spiral path.

In the ATR element of the present invention, the element body preferably has a cylindrical shape.
In the cylindrical element body, the reflection surface is an arc surface, and this reflection surface has a constant distance from the axis of symmetry.

In the ATR element of the present invention, it is preferable that the element main body is provided such that the incident part and the emission part form a recess in the end face.
This is because it is easier to form the incident portion and the emission portion in the depression than to form the end surface of the element body protruding.

  In the ATR element of the present invention, it is preferable that the incident part and the emission part are formed continuously with the outer periphery of the end face in order to increase the number of reflections.

The present invention provides an immersion probe using the ATR element of the present invention described above.
In other words, this immersion probe is composed of an axially symmetric solid body having an element body having a reflection surface that is continuous in the circumferential direction, an incident portion for allowing measurement light to enter the element body, and an incident portion that is incident on the reflection surface of the element body. An ATR element including measurement light reflected from the light source, first light guide means for guiding the measurement light emitted from the light source to the incident part, and measurement light emitted from the emission part. And a second light guide means for guiding to a predetermined part, wherein the ATR element is composed of the ATR element of the present invention described above.
The immersion probe according to the present invention can increase the number of reflections of the measurement light on the reflection surface of the ATR element to be used, and can also effectively use the evanescent light. Therefore, the immersion probe is a substance having a small absorption coefficient for the measurement light. Even if it exists, it contributes to measuring the state of a substance correctly.

In immersion probe of the present invention, the first light guiding means comprises a first linear light guide portion for guiding the measurement light emitted from the light source, the incident part of the measurement light receiving light from a first linear light guide portion A second refracting section that refracts the measurement light emitted from the emitting section along the axial direction of the ATR element, and a second refracting section. a second linear light guide portion for guiding the measurement light receiving light to a given site is preferably provided with a.
By providing the first refracting part corresponding to the incident part, the measurement light can be incident on the incident part from an arbitrary direction. For example, even if the incident part is inclined with respect to the axial direction of the element body, the measurement light guided along the axial direction can be refracted by a necessary angle and incident on the incident part. The same applies to the second refraction part corresponding to the emission part, and the emitted measurement light can be extracted in an arbitrary direction. Note that the first linear light guide and the second linear light guide are typically configured from optical fibers. Further, the first refracting part and the second refracting part are typically constituted by prisms.

  The immersion probe of the present invention further includes a holder for holding the element body on the side where the incident portion and the emission portion are provided, and this holder hermetically seals the region including the incidence portion and the emission portion from the outside. It is preferable to do. By doing so, it can avoid that a measuring object adheres to an entrance part and an output part.

Furthermore, in the immersion probe of the present invention, the first light guide means includes optical means for collimating the measurement light toward the incident portion, and the second light guide means collects the measurement light emitted from the emission portion. It is preferable to provide optical means for emitting light.
The collimating optical means is effective for reducing the diffusion loss at the incident portion, and the condensing optical means is effective for reducing the signal light loss.

  According to the present invention, by using an ATR element having a side surface continuous in the circumferential direction as a reflection surface, the measurement light is continuously reflected on the reflection surface, thereby realizing the number of times of reflection that has not been obtained so far. To do. As a result, it is possible to accurately measure the state of a substance even when the measurement light in the near infrared region is used and the substance has a small absorption coefficient with respect to the measurement light.

  Furthermore, according to the present invention, regardless of whether organic or inorganic, synthetic resin products, liquid crystal products, pigment products, etc., which have a synthetic reaction in the production process, can be obtained by monitoring the synthetic reaction process. The final product to be produced can be suitably produced, and a method for producing a reaction product can be provided. Moreover, not only process management related to manufacturing in various fields such as chemicals, pharmaceuticals, powdered industrial products, foods, etc., but by industry, various resins represented by chemicals, polyurethanes, polyesters, epoxies, reactive hot melts, etc. It can be used widely for plastics, testing / analysis / measurement, pharmaceuticals / biotechnology, education / research institutes, etc.

It is a figure which shows the cylindrical ATR element in this embodiment, (a) is a top view, (b) is a side view. It is a figure explaining the condition A of this embodiment. It is a figure explaining the condition B of this embodiment. FIG. 2 is a diagram schematically illustrating a measurement light passing path in the ATR element of FIG. 1, where (a) and (b) indicate a forward path, and (c) and (d) indicate a return path. It is a figure which shows the other form of the entrance plane in this embodiment, and an output surface. It is a figure which shows the structure of the spectrophotometer using the ATR element of this embodiment. The structure of the immersion probe used for the spectrophotometer of FIG. 6 is shown, (a) is sectional drawing containing an entrance plane, (b) is sectional drawing containing an output surface. It is a figure which shows the outline | summary of the experiment conducted in order to confirm the effect of this embodiment. It is a graph which shows the result of Example 1 and the comparative example 1, (a) shows the result using the immersion probe by this embodiment, (b) shows the result using the conventional immersion probe. It is a graph which shows the result of Example 2 and the comparative example 2, (a) shows the result using the immersion probe by this embodiment, (b) shows the result using the conventional immersion probe.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
As shown in FIG. 1, the ATR element 10 according to the present embodiment includes an element main body 11, and an incident surface 19 and an emission surface 21 that are provided integrally with the element main body 11 and are formed on the end surface on the same side. ing.
[Element body 11]
The element body 11 has a cylindrical shape that is one form of axial symmetry, and has an outer peripheral surface 13, one end surface (first end surface) 15 and the other end surface (second end surface) that face each other in the direction of the symmetry axis y. 17 is provided. Here, the outer peripheral surface 13 is a surface that divides the element body 11 from its periphery, but the ATR element 10 functions as a surface that reflects light traveling inside the element body 11 on the inside thereof. Therefore, the outer peripheral surface 13 may be referred to as the reflective surface 13 for matters relating to light reflection.

The element main body 11 has a high refractive index, and a material that can cause total reflection when irradiated with light can be widely applied. For example, quartz glass, sapphire, cubic zirconia (cubic-ZrO ₂ ), zinc selenide (ZnSe), zinc sulfide (ZnS), diamond, and the like are applicable. Among these, considering the cost, cubic zirconia or sapphire is preferable because it has a high refractive index and is inert to the specimen.

[Incident surface 19]
The incident surface 19 is provided on the first end surface 15 of the element body 11, and when the measurement target is irradiated with infrared light as measurement light by the immersion probe including the ATR element 10, the measurement light is transmitted to the element body 11. It is the surface which makes it enter.
The incident surface 19 is formed so that the normal N thereof satisfies the following two conditions A and B with respect to the reflecting surface 13. These two conditions A and B are necessary for the measurement light incident on the ATR element 10 to follow the spiral passing path toward the second end face 17 by repeating the reflection on the reflecting surface 13 a plurality of times. It is. The normal N of the incident surface 19 substitutes for the optical axis of the measurement light.
Note that the actual measurement light DL is a light beam having a constant intensity distribution introduced by, for example, an optical fiber, and this light beam passes through the reflection surface 13 of the ATR element 10 in a spiral shape in the presence of evanescent light. Although the path will be traced, in the following description, for the sake of simplicity, the incident / reflection of light will be described with a simple model.

Condition A is that the normal line N of the incident surface 19 exists in an area of 80% or more and less than 100% of the radius r of the reference cross section x orthogonal to the symmetry axis y, as shown in FIG. Stipulate. This condition A is required in order for the measurement light DL to be reflected more on the reflecting surface 13. That is, as can be seen by comparing FIG. 2B and FIG. 2C, the number of times the measurement light DL is reflected by the reflection surface 13 is more incident when the measurement light DL is incident closer to the outer peripheral surface (reflection surface) 13. Become more.
According to the condition A, the incident surface 19 of the present embodiment is provided continuously with the outer peripheral surface 13 of the first end surface 15. As described above, by providing the incident surface 19 on the outermost periphery of the element body 11, it is possible to increase the number of times reflected by the reflecting surface 13.

Next, the condition B defines that the angle θ _NS formed by the normal line N of the incident surface 19 and the reference cross section x is 45 degrees or less. This condition B is required for the measurement light DL to follow a spiral passage route.
That is, as shown in FIG. 3A, if the normal line N is parallel to the reference section x, that is, if the angle θ _NS is 0 degree, the measurement light DL is reflected light having the opposite direction on the reflection surface 13. Therefore, theoretically, the measurement light DL is repeatedly reflected within the same reference cross section x.
In order to leave the state of FIG. 3A and the measurement light DL follows the spiral passage route, the angle θ _NS only needs to exceed 0 degree. However, if the angle θ _NS is too large as shown in FIG. 3B, the pitch of the spiral in the passage route becomes large, which is disadvantageous in increasing the number of reflections. Therefore, as shown in FIG. 3C, it is preferable to set the angle θ _NS to 45 degrees or less. Since the number of reflections increases as the angle θ _NS is smaller, the angle θ _NS is more preferably 30 degrees or less, and further preferably 15 degrees or less.

Next, the incident surface 19 is provided by forming a recess 20 in the first end surface 15. That is, the hollow 20 is formed by cutting a part of the originally flat first end surface 15, and the wall surface formed along with the formation of the hollow 20 is the incident surface 19. The wall surface (incident surface 19) is formed in a flat shape. In addition, as long as the interference of incident light can be reduced, the depressions 20 may be provided at a plurality of locations in the same rotational direction when viewed from the first end surface 15 in view of securing the intensity of incident light.
From the viewpoint of reducing the loss of the measurement light DL due to reflection or refraction at the joint surface, it is preferable that the element body 11 including the protruding portion is integrally formed. Since it can form integrally, it is suitable.
As shown in FIGS. 5C and 5D, the incident surface 19 can also be formed by projecting a part of the flat first end surface 15 together with the emission surface 21. In this case, when manufacturing the element main body 11, a method in which the protruding portion and the main part of the element main body 11 are separately manufactured and bonded can be considered. In this case as well, measurement by reflection or refraction at the bonding surface is possible. From the viewpoint of reducing the loss of the light DL, it is preferable that the element body 11 is integrally formed including the protruding portion.
In realizing this integrated structure, after the element main body 11 is formed to have a dimension that takes into account the protruding portion, portions other than the protruding portion may be removed by cutting.
Thus, when forming one incident surface 19, it is better to cut the recess 20 (see FIG. 1B) than to cut a portion other than the protruding portion (FIG. 5C, (See (d)), which is preferable from the viewpoint of man-hours and material costs. However, when a plurality of incident surfaces are formed, any method can be employed from the viewpoint of man-hours and material costs. This also applies to the emission surface 21.

[Exit surface 21]
The exit surface 21 is provided to allow the measurement light DL incident from the entrance surface 19 to be extracted outside after repeatedly reflecting on the reflecting surface 13 a plurality of times and following a spiral passage. Therefore, the emission surface 21 is provided at a position on the passage route. Similarly to the incident surface 19, the exit surface 21 is also provided in the recess 22.
The exit surface 21 of the present embodiment is the first end surface 15 and is provided on the opposite side of the center from the side on which the entrance surface 19 is provided. Therefore, the exit surface 21 has the above-described condition A and condition B similarly to the entrance surface 19. However, this is a preferred form, and basically functions as long as the position corresponds to the spiral passage route.
As described above, since the measurement light DL is a light beam having a constant intensity distribution, the light beam is always emitted from the emission surface 21 by passing through the spiral passage path P. Because.

[Reflection form]
As shown in FIGS. 4A and 4B, the ATR element 10 described above causes total reflection at the reflection surface 13 when the measurement light DL enters the element body 11 from the incident surface 19. While repeating, the spiral passage route P is traced from the first end face 15 side toward the second end face 17 side, and reaches the second end face 17. What has been discussed so far is the forward P _O of passage path P. As shown in FIGS. 4C and 4D, the measurement light DL that has reached the second end surface 17 is reflected by the second end surface 17, and this time toward the first end surface 15 side, the reflecting surface 13 is reflected. in while repeating total reflection, helical passage path P, i.e. it follows the forward path P _I. The measurement light DL is emitted outward from an emission surface 21 provided on the first end face 15. The reflection surface 13 of the ATR element 10 only needs to be partly in contact with the measurement target. However, from the viewpoint of effectively using all of the spiral passage path P, the ATR element 10 is immersed in the measurement target. It is preferable that the entire surface of the reflecting surface 13 is in contact with the measurement target.

As described above, according to the ATR element 10, the measurement light DL is continuously reflected on the reflection surface 13 that is continuous in the circumferential direction, and the reflection is also continuous in the axial direction. Can be significantly increased. Moreover, according to the ATR element 10, since the passage path P of the measuring light DL is composed of forward P _O and forward P _I, as compared with when the passing path P consists only forward P _O, it can double the number of reflections.

[Example of changing the exit surface and reflection surface]
The entrance surface 19 and the exit surface 21 of the ATR element 10 are provided in independent recesses 20 and 22, respectively, but the present invention connects the recesses 20 and 22 as shown in FIGS. 5 (a) and 5 (b). Thus, the incident surface 19 can be provided at one end of the common slope, and the exit surface 21 can be provided at the other end.
Further, as described above, in the present invention, as shown in FIGS. 5C and 5D, the incident surface 19 and the emission surface 21 can be formed by projecting a part of the first end surface 15. .

[Spectrophotometer]
Next, a Fourier Transform Infrared Spectroscopy spectrophotometer 1 using the ATR element 10 will be described with reference to FIGS.
As shown in FIG. 6, the spectrophotometer 1 includes an ATR probe 30 including an ATR element 10, a light source 3, a spectrometer 5, a photodetector 7, and a data processing / display device 9. . An optical fiber is connected between the light source 3 and the ATR probe 30, between the ATR probe 30 and the spectrometer 5, between the spectrometer 5 and the photodetector 7, and between the photodetector 7 and the data processing / display device 9. ing.

The light source 3 generates the measurement light DL and emits it toward the ATR probe 30 (ATR element 10). The light source 3 is not particularly limited, and a halogen tungsten lamp and other known light sources can be used.
Before the measurement light DL is incident on the incident surface 19 of the ATR element 10, it is effective to reduce the diffusion loss on the incident surface 19 by passing the collimating lens 4 through the collimating lens 4.
Further, when the measurement light DL is incident on the incident surface 19, it is effective to reduce the reflection loss at the incident surface 19 to be perpendicular to the incident surface 19.
Further, it is effective to reduce the signal light loss by condensing the measurement light DL emitted from the emission surface 21 by passing through the condenser lens 6 before entering the optical fiber 37.

The spectroscope 5 receives the light emitted from the ATR probe 30 and divides it by wavelength. The spectrometer 5 is not particularly limited, and a diffraction grating spectrometer, an FTIR spectrometer, and other known spectrometers can be used.
The photodetector 7 receives and detects the light separated by the spectrometer 5. The photodetector 7 is not particularly limited, and a photodiode, an avalanche photodiode, a photomultiplier tube, and other known photodetectors can be used.
The data processing / display device 9 generates vector information based on the infrared light received from the photodetector 7 and displays the generated spectrum information as image information. The data processing / display device 9 is not particularly limited, and a personal computer can be used for the data processing portion, and a display device attached to the personal computer can be used for the display portion. .

As shown in FIG. 7, the ATR probe 30 includes a holder 31 on the first end face 15 side of the ATR element 10.
The holder 31 holds the optical fiber 35 that guides the measurement light DL irradiated to the incident surface 19 from the light source 3 while holding the first end face 15 side. In addition, the holder 31 fixes an optical fiber 37 that guides the measurement light DL emitted from the emission surface 21 to the spectrometer 5.
An O-ring 39 is provided between the holder 31 and the ATR element 10 so as to be hermetically sealed from the outside, preventing a measurement target from entering the holding portion and adhering to the entrance surface 19 and the exit surface 21. To do.
Since the ATR element 10 is provided with the entrance surface 19 and the exit surface 21 on the first end surface 15, the optical fiber 35 and the optical fiber 37 can be disposed on the first end surface 15 which is one end surface, and the inside is hermetically sealed. It is sufficient to provide only one holder 31 to be stopped.
As shown in FIG. 7, in the present invention, the measurement light DL is refracted by the prism 23 and incident on the incident surface 19, and the measurement light DL emitted from the emission surface 21 is refracted by the prism 23. Allow. By using the prism 23, the optical fiber 35 can be routed parallel to the symmetry axis y.

As shown in FIG. 8, the spectrophotometer 1 is configured such that the measurement light DL from the light source 3 is incident on the incident surface 19 of the ATR element 10 via the optical fiber 35 in a state where the ATR probe 30 is immersed in the liquid measurement target S. The measurement light DL incident and emitted from the emission surface 21 is received by the optical fiber 37 and guided to the spectrometer 5. Thereafter, the spectral state of the measurement target is displayed through the photodetector 7 and the data processing / display device 9, whereby the reaction state of the measurement target can be grasped.
In this process, in the ATR element 10, the measurement light DL is reflected by the reflection surface 13 many times, and thus the degree of absorption of the specific wavelength for the measurement target S becomes significant. In addition, since the ATR probe 30 measures the measurement object S in contact with the outer peripheral surface 13 of the ATR element 10, there is little possibility that a measurement error due to the presence of bubbles occurs. Therefore, the spectrophotometer 1 using the ATR element 10 can measure with high accuracy.
The measuring object S of the spectrophotometer 1 is arbitrary, but when the reaction liquid in the process of producing a synthetic resin containing a reactive group (for example, -NCO, -OH, -COOH) is used as the measuring object S, the degree of progress of the reaction Can be grasped accurately.
Therefore, regardless of whether organic or inorganic, synthetic resin products, liquid crystal products, pigment products, etc. that have a synthetic reaction in the manufacturing process can be manufactured by monitoring the synthetic reaction process to produce the desired final product. In addition to process management related to manufacturing in various fields such as chemicals, pharmaceuticals, powdered industrial products, foods, etc., chemicals, polyurethane, polyester, epoxy, reactive hot melts are classified by industry. It can be used in a wide variety of applications such as various types of resins and plastics, testing / analysis / measurement, pharmaceuticals / biotechnology, education / research institutions.

[Example]
Hereinafter, the present invention will be described in more detail based on examples.
Example 1
An experiment for confirming the effect of the ATR element 10 according to the present embodiment, particularly an experiment for intentionally generating bubbles around the ATR element 10 was performed.
The manufacturing conditions of the ATR element (FIG. 1) used in the experiment are as follows.
Material: Sapphire Shape: Cylindrical (diameter 20 mm, effective length 30 mm immersed in measurement object S)
Angle θ _NS : 2.5 degrees (estimated spiral pitch 1.75 mm)
Measurement light incident radius position: 0.915r (reflection path is estimated dodecagonal shape)
Estimated number of reflections: 411 times The conditions that constitute the spectrophotometer are as follows.
Light source: halogen tungsten lamp “HL-2000” manufactured by Ocean Optics
Spectrometer: Diffraction grating spectrometer “MICROHR” manufactured by HORIBA, 600 lines / mm
Photodetector: APD detector “SPD-A-M1” manufactured by AUREA
In the experiment, bubbles are blown after a predetermined time has elapsed from the start of measurement (see FIG. 8). In addition, distilled water is used as the measuring object S, and the spectral wavelength of the spectroscope 5 is 1400 nm.
(Comparative Example 1)
In the same manner as in Example 1, a transmission probe (“IN237P10” manufactured by Hellma) 130 having a gap T filled with the measuring object S was also performed.
The results are shown in FIG. 9, whereas in Comparative Example 1 (FIG. 9B), the measurement result greatly fluctuates after starting the blowing of bubbles, whereas Example 1 according to the present embodiment (FIG. 9). (A)), it was confirmed that there is no difference in the measurement results before and after the blowing of bubbles. That is, in this embodiment, it can be seen that the measurement result is not affected by the presence or absence of bubbles.

(Example 2)
The ATR element 10 of Example 1 was immersed in distilled water as the measuring object S, and the absorbance spectrum was measured (FIG. 10 (a)).
The measurement conditions were the spectrophotometer of Example 1, and the selected wavelength of the spectroscope was set in a range of 1000 nm to 1700 nm in 1 nm increments.
(Comparative Example 2)
In the same manner as in Example 2, an absorbance spectrum was measured using an ATR element “661.820-NIR” manufactured by Hellma (FIG. 10B).
The measurement results of Example 2 and Comparative Example 2 are also shown in FIG. In the absorbance spectrum of the comparative example (FIG. 10 (b)), no peak can be observed, whereas in the absorbance spectrum of Example 2 (FIG. 10 (a)), 1070, 1140, 1210, 1440 nm. There is a clear peak in the vicinity. These peaks are presumed to originate from water-specific (—OH) bonds. Although illustration is omitted, since the spectrum according to Example 2 has been confirmed to have high reproducibility when repeatedly measured, the spectrophotometer of the present embodiment is used to deepen consideration of spectra of various substances. Thus, it is expected that a substance existing around the ATR element 10 according to the present embodiment can be identified.

The preferred embodiment of the present invention has been described above. However, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate without departing from the gist of the present invention.
For example, in the element body 11, the first end surface 15 and the second end surface 17 are orthogonal to the symmetry axis y, but the present invention is not limited to this and may be inclined with respect to the symmetry axis y. In the element body 11, the first end surface 15 and the second end surface 17 are parallel to each other. However, the present invention is not limited to this, and for example, the directions may be inclined opposite to each other.

  Thus, according to the present invention, regardless of organic or inorganic, synthetic resin products, liquid crystal products, pigment products, etc., if there is a synthetic reaction in the manufacturing process, by monitoring the synthetic reaction process, The desired final product can be manufactured suitably. Not only process management related to manufacturing in various fields such as chemicals, pharmaceuticals, powdered industrial products, foods, etc. It can be used in a wide variety of applications such as epoxy, various resins and plastics typified by reactive hot melt, testing / analysis / measurement, pharmaceuticals / bio, education / research institutes, etc.

DESCRIPTION OF SYMBOLS 1 Spectrophotometer 3 Light source 4 Collimating lens 5 Spectrometer 6 Condensing lens 7 Photo detector 9 Data processing / display apparatus 10 ATR element 11 Element main body 13 Outer peripheral surface, reflecting surface 15 First end surface 17 Second end surface 19 Incident surface 21 Outgoing surfaces 20 and 22 Depression 23 Prism 30 ATR probe 31 Holder 35 and 37 Optical fiber 39 O-ring DL Measurement light N Normal line T Air gap P Passage path P _O Outbound path P _I Return path

Claims (8)

An element body having an axially symmetric solid body and having a reflective surface that is continuous in the circumferential direction and a pair of end surfaces that are opposed in the axial direction;
An incident part for allowing measurement light to enter the element body;
An emission part that is incident from the incident part and is reflected by the reflection surface of the element body and is emitted to the outside; and
The measurement light incident from the incident portion is an ATR element that is emitted outward from the emission portion, following a spiral passage path while being repeatedly reflected by the reflection surface,
The incident portion and the emitting portion are disposed on any one of the pair of end surfaces of the element body ,
The incident portion is
In the reference cross section (x) orthogonal to the symmetry axis of the element body, it is at a position of 80% or more and less than 100% of the distance from the symmetry axis to the outer periphery of the reference cross section,
Said reference section and is greater than 0 degrees, that not make an angle of less than 45 degrees,
An ATR element characterized by the above. The element body is
Having a cylindrical shape,
The ATR element according to claim 1 . The entrance portion and the exit portion, Ru provided by forming a recess in said end face,
ATR element according to claim 1 or claim 2. The incident part and the emission part are formed continuously to the outer periphery of the end face.
The ATR element according to claim 3 . An element main body having an axially symmetric solid body and having a reflection surface continuous in the circumferential direction, an incident portion for allowing measurement light to be incident on the element main body, an incident light from the incident portion, and reflected by the reflection surface of the element main body An ATR element comprising: an emission part from which the measurement light is emitted to the outside;
First light guiding means for guiding the measurement light emitted from a light source to the incident portion;
A second light guide means for guiding the measurement light emitted from the emission section to a predetermined site,
The ATR element is the ATR element according to any one of claims 1 to 4 .
An immersion probe characterized by that. The first light guide means includes
A first linear light guide portion for guiding the measurement light emitted from the light source, a first refracting portion for refracting toward the measurement light received light to the incident portion from the first linear light guide portion, With
The second light guide means includes
A second refracting portion for refracting along the measurement light emitted from the emitting portion in the axial direction of the ATR element, second linear guiding the measurement light receiving optical from said second bent portion to a predetermined site A light guide,
The immersion probe according to claim 5 . A holder for holding the element body on the side where the incident part and the emission part are provided;
The holder hermetically seals an area including the incident portion and the emission portion from the outside.
The immersion probe according to claim 5 or 6 . The first light guide means includes
Optical means for collimating the measurement light toward the incident portion;
The second light guide means includes
Comprising optical means for condensing the measurement light emitted from the emission part,
Immersion probe according to any one of claims 5 to claim 7.

Images