JP2014238333A - Liquid immersion probe and infrared spectrophotometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid immersion probe and an infrared spectrophotometer that enable a status of a measurement object to be easily and surely grasped.SOLUTION: A liquid immersion probe according to the present invention comprises: a plano-convex spherical lens; light emission means for emitting a ray onto a plane surface of the plano-convex spherical lens; and light reception means for receiving the ray to be emitted from the light emission means and reflected upon a coronary shape convex surface, and to be emitted from a plane surface. A light emission position of the light emission means and a light reception position of the light reception means are disposed point-symmetrically to a center of the plane surface with reference to the plane surface of the plano-convex spherical lens. The plano-convex spherical lens may be composed of sapphire or quartz. Further, the liquid immersion probe may include light shield means for shielding a part of the ray to be emitted from the light emission means, and further, the liquid immersion probe may have a metal film evaporated on an outer surface of the coronary shape convex surface of the plano-convex spherical lens. The liquid immersion probe may include a plurality of pairs of light emission means and the light reception means.

Description

  The present invention relates to an immersion probe and an infrared spectrophotometer.

  Conventionally, an immersion probe is used, for example, to measure the progress of a reaction in a chemical reaction tank. (1) As such an immersion probe, a light-emitting optical fiber as a light-emitting means and a light-receiving optical fiber that receives light from the light-emitting optical fiber are provided in an optical path from the light-emitting optical fiber to the light-receiving optical fiber. A cavity portion in which a reaction liquid to be measured can be interposed is provided (see JP 2009-250825 A). Then, when light is emitted from the light-emitting optical fiber in a state where the immersion probe is immersed in the reaction liquid, a part of the wavelength of light is absorbed when the light passes through the reaction liquid interposed in the cavity. Is done. For this reason, by analyzing the light received by the light receiving optical fiber, it is possible to grasp the state of the reaction solution and the like, and thus the progress of the reaction can be measured.

  One of the methods for analyzing a substance is an attenuated total reflection method (ATR method (attenuated total reflection method)). (2) In this total reflection attenuation method, as shown in FIG. 6, when the light beam 103 is incident on the surface of the measurement object 102 at an incident angle greater than the critical angle, the light beam 103 is reflected at the interface between the prism 101 and the measurement object 102. Total reflection. Then, the evanescent wave penetrates to the measurement object 102 side during total reflection. Since the light beam is absorbed (penetrated) inherent to the measurement object 102 in total reflection, the state of the measurement object can be grasped by analyzing the received light beam 103. As an element for measuring the state of a substance using this total reflection attenuation method, an ATR probe is known (see Japanese Patent Application Laid-Open No. 2004-85433). Such an ATR probe includes an optical fiber for light emission, an optical fiber for light reception, And an ATR crystal, and the ATR crystal has a pyramid portion or a cone portion that reflects light rays. The ATR probe further includes an incident lens that is disposed between the outgoing optical fiber and the ATR crystal and adjusts the optical path so that parallel light is incident on the ATR crystal. The ATR probe is provided between the light receiving optical fiber and the ATR crystal, and includes an exit lens for adjusting the optical path so that parallel light is incident on the light receiving optical fiber. By the incident lens and the exit lens, the parallel light beam is totally reflected at the pyramid portion of the ATR crystal, and the totally reflected light beam is converted into the parallel light beam and received by the light receiving optical fiber, and the above-described measurement is performed. .

JP 2009-250825 A JP 2004-85433 A

  However, (1) In the conventional immersion probe having a cavity, accurate measurement cannot be performed unless the liquid to be measured flows into the cavity. Furthermore, if bubbles are present in the liquid interposed in the cavity, accurate measurement cannot be performed.

  (2) In the ATR probe, even if the optical lens for adjusting the optical path is provided as described above, the light is surely totally reflected by the ATR crystal and is accurately received by the light receiving optical fiber. For this purpose, it is necessary to accurately position the light emitting optical fiber, the light receiving optical fiber, the optical lens, and the ATR crystal. That is, even if a slight deviation occurs in the positioning, the light receiving optical fiber cannot accurately receive the light beam and accurate measurement cannot be performed. Furthermore, in the total reflection attenuation method, as described above, it is necessary to allow light to be incident on the interface with the measurement object at an incident angle greater than the critical angle, and the critical angle differs depending on the refractive index of the measurement object. It is necessary to perform the positioning as described above with accuracy each time.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an immersion probe and an infrared spectrophotometer capable of easily and reliably performing high-accuracy measurement.

An immersion probe made to solve the above problems is
A plano-convex spherical lens;
A light output means for emitting light to the plane of the plano-convex spherical lens;
A light receiving means for receiving the light emitted from the light emitting means, reflected by the spherical convex surface, and emitted from the plane;
With the plane of the plano-convex spherical lens as a reference, the light output position of the light output means and the light reception position of the light receiving means are arranged point-symmetrically with respect to the center of the plane.

  When the immersion probe is immersed in the liquid to be measured and emits a light beam from the light output means to the plane of the plano-convex spherical lens, the light beam is reflected by the spherical convex surface of the plano-convex spherical lens. The light beam absorbs a wavelength specific to the object to be measured. The light beam reflected by the spherical convex convex surface is emitted from the plane of the plano-convex spherical lens, and is received by the light receiving means in which the light receiving position is arranged at the light output position of the light output means and the point target position. Therefore, by analyzing the light received by the light receiving means and specifying the absorbed light, it is possible to determine the state of the measurement target. In addition, since the immersion probe absorbs a part of the light beam by reflecting the light beam at the interface (spherical convex surface) between the plano-convex spherical lens and the liquid to be measured as described above, Compared to an immersion probe having a hollow portion, there is less risk of measurement errors due to the presence of bubbles and the like, and highly accurate measurement can be performed easily and reliably. In addition, since the light beam is reflected by the spherical crown-shaped convex surface of the plano-convex spherical lens, the light beam incident from the light exit means is easily totally reflected by the spherical crown-shaped convex surface, and therefore, a conventional ATR crystal having a pyramid portion is used. Compared to the above, the positioning of the light emitting means, the light receiving means, and the plano-convex spherical lens is less required to be highly accurate, and highly accurate measurement can be performed easily and reliably.

  The plano-convex spherical lens may be made of sapphire or quartz. Thereby, since sapphire and quartz have a high refractive index, the light beam can be easily totally reflected on the convex surface of the spherical crown even when measuring various substances. In addition, since sapphire and quartz are relatively inactive, there is little possibility of deteriorating the plano-convex spherical lens even when immersed in an organic solvent.

  It is preferable that the immersion probe further includes a light blocking unit that blocks a part of the light beam emitted from the light output unit. Thereby, among the light rays emitted from the light exit means, the light rays that are not totally reflected by the spherical convex surface can be shielded by the light shield means, so that unnecessary propagation of the light rays can be prevented.

  In the immersion probe, a metal film may be deposited on the outer surface of the spherical convex surface of the plano-convex spherical lens. Thereby, absorption of the specific light ray on the spherical crown-shaped convex surface is more likely to occur, and more accurate measurement can be performed.

  The immersion probe may include a plurality of pairs of the light emitting means and the light receiving means. Thereby, since the light quantity of the light ray totally reflected on the spherical crown-shaped convex surface can be increased, the measurement accuracy can be increased.

  The light exiting means and the light receiving means may include an optical fiber disposed substantially perpendicular to the plane of the plano-convex spherical lens. As a result, light can be easily incident on the plano-convex spherical lens and totally reflected.

  Furthermore, it is preferable that the distance between the light exit position of the light exiting means and the light receiving position of the light receiving means is 80% or more of the diameter of the plane with respect to the plane of the plano-convex spherical lens. As a result, the angle (incident angle) at which the light beam from the light exiting unit enters the spherical crown-shaped convex surface is likely to be an acute angle with respect to the interface, and the incident angle is likely to be greater than the critical angle in various measurement objects. The light beam can be totally reflected by the convex surface of the spherical crown.

  The plano-convex spherical lens preferably has a concave surface along the convex surface on the plane side. As a result, the light beam totally reflected on the spherical crown-shaped convex surface is totally reflected toward the convex surface on the concave surface, is incident again on the spherical crown-shaped convex surface, and is totally reflected on this spherical crown-shaped convex surface, the number of times the light beam is totally reflected on the spherical crown-shaped convex surface. To increase. When the number of times of total reflection of light rays on the spherical crown-shaped convex surface increases in this way, the amount of light rays absorbed at the interface of the measurement object increases, so that more accurate measurement can be performed.

  Another invention for solving the above problem is an infrared spectrophotometer including the immersion probe. Since the infrared spectrophotometer includes the immersion probe, highly accurate measurement can be performed easily and reliably.

  The “spherical crown” means a curved surface portion when a sphere is cut in one plane. “Planar reference of plano-convex spherical lens” means that the projection position on the plane of the plano-convex spherical lens is used as a reference.

  As described above, the immersion probe and infrared spectrophotometer of the present invention can easily and reliably perform highly accurate measurement.

It is the schematic of the infrared spectrophotometer which concerns on one Embodiment of this invention. It is typical side surface sectional drawing which shows the immersion probe of the infrared spectrophotometer of FIG. FIG. 3 is a schematic diagram illustrating an optical path of infrared light of the immersion probe in FIG. 2. FIG. 3 is a schematic plan cross-sectional view showing an immersion probe according to a different form from the immersion probe of FIG. 2. FIG. 3 is a schematic side sectional view showing an immersion probe according to a different form from the immersion probe of FIG. 2. It is typical sectional drawing which shows the conventional optical probe.

[First embodiment]
<Infrared spectrophotometer>
An infrared spectrophotometer 1 in FIG. 1 is a Fourier transform infrared spectrophotometer, and is a device that obtains spectral information by applying infrared light to a measurement target to obtain characteristics, states, and the like of the measurement target. For example, the infrared spectrophotometer 1 can measure the reaction state of the organic solvent 5.

  The infrared spectrophotometer 1 includes an immersion probe 2, a photometer body 3, and a connection portion 4 that connects the immersion probe 2 and the photometer body 3.

(Immersion probe)
The immersion probe 2 is an optical element that obtains reflected light by irradiating a measurement target with infrared light. By immersing the immersion probe 2 in the organic solvent 5, it is possible to irradiate infrared light and obtain reflected light.

  As shown in FIG. 2, the immersion probe 2 includes a plano-convex spherical lens 11, a light exiting means 12, a light receiving means 13, and a support portion 14 that supports them.

  As shown in FIG. 3, the plano-convex spherical lens 11 has a circular plane 15 and a spherical crown-like convex surface 16, and is formed in a substantially hemispherical shape. The plano-convex spherical lens 11 is disposed at the distal end portion of the immersion probe 2, and the spherical crown-shaped convex surface 16 is disposed on the distal end side with respect to the flat surface 15. Further, a light output means 12 and the light receiving means 13 described later are in contact with the flat surface 15 of the plano-convex spherical lens 11. For this reason, the plano-convex spherical lens 11 receives the light beam from the light output means 12 from the plane 15 and totally reflects this light beam at the interface (spherical convex surface 16) with the object to be measured. The light is emitted from the plane 15 toward the means 13.

  The plano-convex spherical lens 11 is not particularly limited, but may be made of diamond, sapphire, quartz or the like. Among these, sapphire or quartz is preferable from the viewpoint of high refractive index, inert properties, workability, and the like.

  The lower limit of the refractive index of the plano-convex spherical lens 11 is preferably 1.43, and more preferably 1.45. If the refractive index is less than the lower limit, the difference in refractive index from the measurement target becomes too small, and the critical angle for total reflection may be too small. The upper limit of the refractive index is not particularly limited, and can be set to 2.5, for example. The refractive index is a value measured using a light beam having a wavelength of 589.3 nm (sodium D-line) at a temperature of 25 ° C. and a humidity of 50%. The average value of the refractive index and the refractive index of extraordinary rays.

  Further, the plano-convex spherical lens 11 is not particularly limited, but may have a metal film deposited on the outer surface of the spherical crown-shaped convex surface 16. By providing the metal film in this manner, absorption of specific light rays on the spherical crown-shaped convex surface 16 is more likely to occur, and measurement with higher accuracy can be performed. Although it does not specifically limit as a metal used for this metal film, Silver, gold | metal | money, copper, zinc, aluminum, potassium etc. are mentioned. Further, the thickness of the metal film is not particularly limited, but is preferably 30 nm or more and 70 nm or less, and preferably 40 mm or more and 60 mm or less. When the thickness of the metal film is out of the above range, the effect of improving the measurement accuracy by the metal film may not be sufficiently obtained.

  Further, the radius of the flat surface 15 of the plano-convex spherical lens 11 is not particularly limited, but the lower limit of this radius is preferably 2 mm, and more preferably 2.5 mm. Further, the upper limit of this radius is preferably 4 mm, more preferably 3.5 mm. When the radius of the flat surface 15 of the plano-convex spherical lens 11 is less than the above lower limit, the plano-convex spherical lens 11 becomes too small, so that it is difficult to accurately dispose the light emitting means 12 and the light receiving means 13, and accurate measurement is performed. There is a risk that it will be difficult to perform. On the other hand, if the radius exceeds the upper limit, the immersion probe 2 may become too large, and the handleability of the immersion probe may be impaired.

  The height of the spherical crown-shaped convex surface 16 is most preferably one time the radius of the flat surface 15, that is, the plano-convex spherical lens 11 is most preferably hemispherical. Here, the height of the spherical crown-shaped convex surface 16 is preferably 0.8 times or more, more preferably 0.9 times or more the radius of the plane 15. If this height is less than the lower limit, total reflection at the interface may be difficult. The upper limit of the height of the spherical crown-shaped convex surface 16 is one time the radius of the plane 15.

  The light output means 12 emits a light beam toward the flat surface 15 of the plano-convex spherical lens 11 to cause the light beam to enter the plano-convex spherical lens 11 and includes an optical fiber. The optical fiber is disposed substantially perpendicular to the plane 15 and can emit light in a direction perpendicular to the plane 15. Here, the light emitting means 12 emits a light beam inclined with respect to the vertical direction in addition to the light beam in the vertical direction. The light exit surface of the optical fiber is in contact with the flat surface 15. The diameter of the core of the optical fiber is not particularly limited, but the lower limit of the diameter is preferably 40 μm, and more preferably 50 μm. Further, the upper limit of the diameter is preferably 600 μm, and more preferably 500 μm. When the diameter of the core of the optical fiber is less than the lower limit, there is a possibility that the light beam cannot be easily incident on the plano-convex spherical lens 11. On the other hand, when the diameter exceeds the upper limit, the immersion probe 2 becomes too large, and the handling property of the immersion probe may be impaired.

  The light receiving means 13 receives the light beam reflected by the spherical convex surface 16 of the plano-convex spherical lens 11 and emitted from the plane 15 of the plano-convex spherical lens 11, and includes an optical fiber. The optical fiber is disposed substantially perpendicular to the plane 15. The light receiving surface of the optical fiber is in contact with the flat surface 15. The diameter of the optical fiber core is not particularly limited, but the lower limit of the diameter is preferably 40 μm, and more preferably 50 μm. Further, the upper limit of the diameter is preferably 600 μm, and more preferably 500 μm. When the diameter of the core of the optical fiber is less than the lower limit, there is a possibility that light cannot be received accurately. On the other hand, when the diameter exceeds the upper limit, the immersion probe 2 becomes too large, and the handling property of the immersion probe may be impaired.

  The light output position 17 of the light output means 12 and the light receiving position 18 of the light receiving means 13 (see FIG. 3) are arranged symmetrically with respect to the center 19 of the plane 15 with respect to the plane 15 of the plano-convex spherical lens 11. Yes. Further, the light exit position 17 and the light receiving position 18 are disposed closer to the outer edge than the center of the plane 15 with respect to the plane 15. Specifically, the distance between the light exit position 17 and the light receiving position 18 may be 80% or more of the diameter of the flat surface 15, and more preferably 83% or more. Thereby, the incident angle on the spherical crown-shaped convex surface 16 of the light beam emitted from the light output means 12 and incident on the spherical crown-shaped convex surface 16 tends to be an acute angle with respect to the interface (incident surface), and the incident angle becomes greater than the critical angle in various measurement objects. It is easy and can easily and reliably totally reflect the light beam on the spherical crown-shaped convex surface 16. On the other hand, the distance between the light exit position 17 and the light receiving position 18 is preferably 90% or less of the diameter of the plane 15 and more preferably 87% or less. Thereby, it is easy to make a light beam accurately incident on the plane 15 from the light exit means 12. The distance between the light output position 17 and the light receiving position 18 means the distance between the center of the light output position 17 and the center of the light receiving position.

  The support portion 14 is formed in a cylindrical shape and incorporates the light exiting means 12 and the light receiving means 13. The plano-convex spherical lens 11 is attached to the tip of the support portion 14. The support portion 14 is not particularly limited, but can be made of PEEK (Polyetherketonetone) resin, Hastelloy, titanium, stainless steel, or the like. Although the length of this support part 14 is not specifically limited, 100 mm or more and 500 mm or less are preferable, and 200 mm or more and 300 mm or less are more preferable. When the length of the support portion 14 is out of the above range, the handleability of the immersion probe 2 may be impaired.

(Photometer body)
The photometer body 3 includes a light source 21 that emits measurement light, an interferometer 22 that generates interference light, a detector 23 that detects interference light, and a conversion processing unit that obtains spectral information by Fourier transforming the detection signal of the detector. 24 and a display unit 25.

  The light source 21 emits infrared rays. Although it does not specifically limit as infrared light to radiate | emit, For example, the infrared light which has a wavelength component of 1 micrometer or more and 11 micrometers can be employ | adopted. The light source 21 is not particularly limited, but a tungsten iodine lamp or a high-intensity ceramic light source can be used.

  The interferometer 22 causes the light emitted from the light source 21 to interfere. The interferometer 22 is not particularly limited, and a Michelson interferometer, a Fizeau interferometer, a Mach-Zehnder interferometer, or the like can be used.

The detector 23 detects the light beam received from the immersion probe 2. The detector 23 is not particularly limited, and a DLATGS (Deuterated L-Aline Triglycine Sulphate) detector, an MCT (Mercury Cadmium Tellurium) detector, a LiTaO ₃ (Lithium Tantalite) detector, or the like can be used.

  The conversion processing unit 24 digitizes the infrared light detected by the detector 23 and creates spectral information by Fourier-transforming the digitized data. The conversion processing unit 24 is specifically a central processing unit or a storage device.

  The display unit 25 displays the spectrum information obtained by the conversion processing unit 24. As the display unit 25, a display, a printer, or the like can be used.

(Connection part)
The connection unit 4 optically connects the immersion probe 2 and the photometer body 3. The connection unit 4 includes a light-emitting optical fiber for causing the light beam from the interferometer 22 to enter the immersion probe 2 and a light-receiving optical fiber for causing the detector 23 to receive the light beam from the immersion probe 2. The light exiting optical fiber and the light receiving optical fiber can be the same as the optical fibers of the light exiting means 12 and the light receiving means 13.

<Advantages>
In the immersion probe 2, the light beam emitted from the optical fiber of the light output means 12 and incident from the flat surface 15 of the plano-convex spherical lens 11 enters the convex surface 16 of the plano-convex spherical lens 11 as shown in FIG. Since the convex surface 16 on which this light ray is incident has a spherical crown shape, the incident light ray is likely to be incident on the interface (convex surface 16) at an acute angle. For this reason, the incident angle of this incident light beam is greater than or equal to the critical angle, and this incident light beam is totally reflected toward the top of the convex surface 16 (the position farthest from the plane 15). This totally reflected light beam is also totally reflected at the top of the convex surface 16. Further, the light beam totally reflected at the apex portion is incident on the spherical crown-shaped convex surface 16 corresponding to the target position at the position where the light is totally reflected first, and is also totally reflected at this portion. The light beam that has been totally reflected a plurality of times at the interface in this way is directed toward the plane 15 and is emitted from the plane 15 toward the light receiving position 18 of the light receiving means 13. Thereby, the light beam totally reflected at the interface is received from the light receiving position 18 of the light receiving means 13. And the state of a measuring object can be judged by analyzing this received light ray and specifying the absorbed light ray. Specifically, the progress of the reaction in the chemical reaction tank can be measured in real time by arranging the immersion probe in the chemical reaction tank, for example.

  The immersion probe 2 performs measurement by absorbing a part of the light beam by reflecting the light beam at the interface (spherical convex surface 16) with the measurement target of the plano-convex spherical lens 11 as described above. Therefore, a measurement error due to the presence of bubbles or the like is less likely to occur than in a conventional immersion probe that transmits light through a cavity.

  Further, as described above, since the light beam is reflected by the spherical crown-shaped convex surface 16 of the plano-convex spherical lens 11, the light beam incident from the light exit means 12 is likely to be totally reflected by the spherical crown-shaped convex surface 16, and thus as in the prior art. Compared with the case where the light is reflected by the pyramid portion of the ATR crystal, the positioning of the light emitting means 12, the light receiving means 13 and the plano-convex spherical lens 11 is less required to be positioned with high accuracy, and the optical path setting for surely reflecting and receiving the light rays. Thus, accurate measurement can be performed easily and reliably.

  Moreover, since the immersion probe 2 has the spherical crown-shaped convex surface 16 as described above, various liquids having different refractive indexes can be measured. That is, the critical angle at the interface differs depending on the refractive index of the measurement object, but there is a light ray incident on the spherical crown-shaped convex surface 16 at a critical angle or more among the light rays emitted from the light output means 12, and this light ray is the interface (convex surface 16). The total reflected light is totally reflected at the top of the convex surface 16 and the convex surface 16 at the target position at the position where the total reflection is first performed as described above. Is received by the light receiving means 13 at the even position of the light emitting means 12. For this reason, various liquids with different refractive indexes can be measured. More specifically, for example, as shown by a two-dot chain line in FIG. The light beam A emitted toward the outer surface of the spherical crown-shaped convex surface 16 and at an obtuse angle compared to the light beam B emitted from the center of the light-emitting surface in the direction perpendicular to the plane 15 as shown by a one-dot chain line in FIG. 16 is incident. The light beam A incident on the spherical crown-shaped convex surface 16 is reflected toward the top of the convex surface 16 and further reflected on the top of the convex portion 16. The light ray A reflected from the top of the convex portion 16 is incident on the spherical crown-shaped convex surface 16 corresponding to the target position of the first reflected position, and is also reflected at this portion. Then, the light beam A is incident on the light receiving surface of the optical fiber of the light receiving means 13 at the opposite position of the outgoing light exit surface. In this manner, the immersion probe 2 is configured such that the light beam emitted from the light exit surface is reflected by the spherical crown-shaped convex surface 16 and is incident on the light receiving surface at the opposite position of the light output surface. Therefore, various liquids having different refractive indexes can be measured.

  Moreover, the immersion probe 2 has the spherical crown-shaped convex surface 16 as described above, and various liquids having different refractive indexes are measured by using light rays having a certain range of incident angles on the spherical crown-shaped convex surface 16. Therefore, unlike the case of using a conventional ATR crystal having a pyramid portion or a cone portion, an incident lens and an exit lens are not essential. That is, for example, in a conventional ATR crystal having a conical portion, when a light beam (light beam) emitted from an optical fiber enters the conical portion of the ATR crystal as it is without passing through the exit lens, the light enters the conical portion. Although the light beam is reflected toward the top of the ATR crystal, the light beam spreads in the radial direction during this reflection. If the light is further reflected at the top, the light beam further spreads in the radial direction, making accurate measurement difficult. For this reason, when using the ATR crystal which has a cone part or a pyramid part as mentioned above, an output lens and an entrance lens are needed. On the other hand, since the liquid crystal probe 2 reflects the light beam at the spherical crown-shaped convex surface 16, accurate measurement is possible without using an exit lens and an entrance lens.

[Second Embodiment]
The immersion probe 30 of FIG. 4 includes a plano-convex spherical lens 11, a plurality of pairs of light output means 32 and light receiving means 33, and a support portion 14 that supports them. In addition, in 2nd embodiment, about the member which has the same structure and function as 1st embodiment, the same code | symbol may be used and the description may be abbreviate | omitted.

  The immersion probe 30 of the second embodiment includes a plurality (seven in the illustrated example) of light exiting means 32 and a plurality of light receiving means 33 corresponding to the light exiting means 32. That is, the light output position of the light output means 32 and the light reception position of the light receiving means 33 are arranged symmetrically with respect to the center 19 of the plane 15 with respect to the plane 15 of the plano-convex spherical lens 11. The light output positions of the plurality of light output means 32 and the light reception positions of the plurality of light receiving means 33 are arranged on the same circle with the plane 15 as a reference.

  The immersion probe 30 according to the second embodiment can increase the amount of light that is totally reflected by the spherical convex surface 16 of the planoconvex spherical lens 11 by emitting light from a plurality of light output means 32. Then, the totally reflected light is received by the light receiving means 33 paired with each light output means 32, and the light amount (total amount) of the light received by the plurality of light receiving means 33 is relatively large. By using the immersion probe 30, more accurate measurement can be performed.

[Third embodiment]
The immersion probe 40 in FIG. 5 includes a plano-convex spherical lens 41, a light exiting means 12, a light receiving means 13, and a support portion 14 that supports the same. In addition, in 3rd embodiment, about the member which has the same structure and function as 1st or 2nd embodiment, the same code | symbol may be used and the description may be abbreviate | omitted.

  The plano-convex spherical lens 41 of the third embodiment includes a flat surface 45, a spherical crown-shaped convex surface 46, and a concave surface 50 along the spherical crown-shaped convex surface 46 on the flat surface 45 side. The concave surface 50 is provided concentrically and similar to the spherical crown-shaped convex surface 46. The plane 45 is provided in an annular shape. The light emitting means 12 and the light receiving means 13 are in contact with the annular flat surface 45.

  The sizes of the spherical crown-shaped convex surface 46 and the concave surface 50 are not particularly limited, but the lower limit of the radius of the concave surface 50 (inner diameter of the annular plane 45) is the radius of the spherical crown-shaped convex surface 46 (circle). 0.8 times the outer diameter of the annular plane 45) is preferred, 0.85 times more preferred, and 0.9 times more preferred. If the radius of the concave surface 50 is less than the lower limit, the effect of increasing the number of reflections by the concave surface 50 may not be sufficiently obtained. On the other hand, the upper limit of the radius of the concave surface 50 is not particularly limited, but is preferably 0.98 times, more preferably 0.95 times the radius of the spherical crown-shaped convex surface 46. If the radius exceeds the upper limit, it may be difficult to form the plano-convex spherical lens 41.

  In the immersion probe 40 of the third embodiment, the light beam totally reflected by the spherical crown-shaped convex surface 46 of the plano-convex spherical lens 41 is incident on the concave surface 50 and is also totally reflected on the concave surface 50. Then, the light beam totally reflected on the concave surface 50 is incident on the spherical crown-shaped convex surface 46 again and totally reflected. After repeating total reflection at the spherical crown-like convex surface 46 and the concave surface 50 in this way, light rays are emitted from the flat surface 45. Thus, since the immersion probe 40 has the concave surface 50, the number of times of reflection on the spherical crown-shaped convex surface 46 increases, so that the number of times of light absorption by the measurement object increases, and more accurate measurement can be performed. it can.

[Other Embodiments]
In addition, the immersion probe and infrared spectrophotometer of this invention can be implemented in the aspect which gave various change and improvement other than the said aspect.

  In the said embodiment, although the light emission means and the light-receiving means were provided with the optical fiber, this invention is not limited to this. Further, the light exiting means and the light receiving means may further include an optical lens as well as an optical fiber. For example, a lens for adjusting the optical path such as a SELFOC (registered trademark) lens or a collimator lens can be disposed between the outgoing optical fiber and / or the receiving optical fiber and the plano-convex spherical lens. Thereby, a desired optical path can be set more reliably. Further, the light emitting means and the light receiving means have been described as contacting the plane of the plano-convex spherical lens. However, the present invention is not limited to this, and a gap may be provided between the light emitting means and the light receiving means and the plano-convex spherical lens.

  In the above embodiment, the plano-convex spherical lens is described as an example of a substantially hemispherical lens, but the present invention is not limited to this, and the plano-convex spherical lens includes a spherical crown-shaped convex surface and a plane opposite thereto. If it has, it will not be limited to a substantially hemispherical shape. Specifically, for example, a plano-convex spherical lens in which a hemispherical portion having a spherical crown-like convex surface as described above and a cylindrical portion having a flat surface as described above and continuing to the hemispherical portion are provided integrally. Even so, it can be employed in the immersion probe.

  Further, the immersion probe may be provided with a light shielding means for shielding unnecessary light (a part of light emitted by the light exiting means) emitted from the light exiting means between the light exiting means and the plano-convex spherical lens. It is. Thereby, it is possible to prevent unnecessary rays from propagating through the plano-convex spherical lens. The light shielding means is not particularly limited. For example, a spacer having a hole having the same diameter as the light exit surface of the light exit means can be used, and this spacer is disposed between the light exit means and the plano-convex spherical lens. By providing, unnecessary light can be shielded.

  Furthermore, the immersion probe is not limited to those used by being immersed in an organic solvent, and can be immersed in various liquids. In addition, in the infrared spectrophotometer, the Fourier transform infrared spectrophotometer is also used. It is not limited, A dispersive infrared spectrophotometer may be sufficient.

  As described above, the immersion probe of the present invention and the infrared spectrophotometer provided with the immersion probe can be used, for example, for measuring the reaction state of an organic solvent.

DESCRIPTION OF SYMBOLS 1 Infrared spectrophotometer 2 Immersion probe 3 Photometer main body 4 Connection part 5 Organic solvent 11 Plano-convex spherical lens 12 Light emitting means 13 Light receiving means 14 Instruction part 15 Plane 16 Convex surface 17 Light emitting position 18 Light receiving position 19 Center 21 Light source 22 Interference Total 23 Detector 24 Conversion processing unit 25 Display unit 30 Immersion probe 32 Light exiting means 33 Light exiting means 40 Immersion probe 41 Plano-convex spherical lens 45 Plane 46 Spherical convex surface 50 Concave surface

Claims (9)

A plano-convex spherical lens;
A light output means for emitting light to the plane of the plano-convex spherical lens;
A light receiving means for receiving the light emitted from the light emitting means, reflected by the spherical convex surface, and emitted from the plane;
An immersion probe in which the light output position of the light output means and the light receiving position of the light receiving means are arranged point-symmetrically with respect to the center of the plane with respect to the plane of the plano-convex spherical lens.   The immersion probe according to claim 1, wherein the plano-convex spherical lens is made of sapphire or quartz.   The liquid immersion probe according to claim 1, further comprising a light shielding unit configured to shield a part of the light beam emitted from the light emitting unit.   The immersion probe according to claim 1, wherein a metal film is deposited on an outer surface of the spherical crown-shaped convex surface of the plano-convex spherical lens.   The immersion probe according to any one of claims 1 to 4, further comprising a plurality of pairs of the light emitting means and the light receiving means.   The immersion probe according to any one of claims 1 to 5, wherein the light exiting means and the light receiving means include an optical fiber disposed substantially perpendicular to a plane of the plano-convex spherical lens.   The distance between the light output position of the light output means and the light receiving position of the light receiving means, which are opposed to each other, with respect to the plane of the plano-convex spherical lens is 80% or more of the diameter of the plane. The immersion probe as described.   The immersion probe according to any one of claims 1 to 7, wherein the plano-convex spherical lens has a concave surface along the convex surface on a flat surface side.   An infrared spectrophotometer comprising the immersion probe according to any one of claims 1 to 8.

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