JP2015081830A - Analyser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized analyser.SOLUTION: An analyser 100 comprises: a light source 10 that emits light with which an analysis area C3 including a sample is irradiated; a reflection mechanism 30 that reflects light from the light source 10 and passes the light through the analysis area C3; and a detector 40 that detects light passing through the analysis area C3. The reflection mechanism 30 reflects the light from the light source 10 with a non-axial parabolic mirror, and also may have a plurality of non-axial parabolic mirrors 31-35 provided in a first area C1 outside the analysis area C3 and a second area C2 facing the first area C1 with the analysis area C3 interposed therebetween. The plurality of non-axial parabolic mirrors 31-35 form a zigzag optical path. The detector 40 may be disposed on at least one of a first detection position 40a provided on a terminal of the zigzag optical path and second detection positions 40b, 40c provided halfway in the zigzag optical path.

Description

  The present invention relates to an analyzer, and more particularly, to an analysis technique using an absorptiometry.

  In recent years, due to increasing environmental awareness, it is required to monitor the concentration of nitrogen oxides and sulfur oxides contained in the exhaust gas of automobiles and the like, and to control the emission amount. As a method for analyzing the component and concentration of a substance contained in such combustion exhaust gas, there is a method of measuring the absorbance of the target substance. Since the spectral distribution of light absorbed by the substance varies depending on the type of substance, the component and concentration of the substance contained in the sample are measured by measuring the absorbance by changing the wavelength of light applied to the sample.

  For example, as an apparatus for analyzing the concentration of sulfur oxide contained in combustion exhaust gas, a configuration using an ultraviolet lamp as a light source can be mentioned. (See Patent Document 1). Moreover, in order to improve the detection accuracy of the trace component contained in the combustion exhaust gas of an automobile, there is an analyzer in which the light from the light source is turned back using a mirror and the optical path length of the light passing through the gas is increased (Patent Document 2). reference).

Japanese Patent Application Laid-Open No. 8-313439 JP 2006-343293 A

  In order to accurately detect a trace component such as a gas, it is desirable to increase the length of the optical path through which the measurement light passes and increase the intensity of the measurement light. However, if a power source with a large capacity is used in order to use a light source with a high output, or if the optical path length is increased, the size of the apparatus will increase.

  The present invention has been made in view of these problems, and provides a miniaturized analyzer.

  In order to solve the above problems, an analyzer according to an aspect of the present invention includes a light source that emits light that strikes an analysis region where a sample exists, a reflection mechanism that reflects light from the light source and passes the analysis region, and an analysis And a detector for detecting light that has passed through the region. The reflection mechanism reflects light from the light source by a non-axial parabolic mirror.

  According to the analyzer of the above aspect, the light that has passed through the analysis region where the sample is present can be collected by the non-axis parabolic mirror and directed to the detector. The intensity of light incident on the detector can be increased as compared with the case where the detector is not provided. Thereby, even if it is a case where the light source with a low output is employ | adopted in order to miniaturize an apparatus, the fall of a measurement precision can be suppressed. That is, by using a non-axial parabolic mirror, the apparatus can be miniaturized while maintaining measurement accuracy.

  The reflection mechanism may include a plurality of non-axial parabolic mirrors provided in a first region outside the analysis region and a second region facing the first region across the analysis region. The plurality of non-axis parabolic mirrors include a first optical path from the first area through the analysis area to the second area, and a second optical path from the second area through the analysis area to the first area. And a detector is arranged at least one of a first detection position provided at the end of the zigzag optical path and a second detection position provided in the middle of the zigzag optical path. Also good.

  The reflection mechanism may include a condensing mirror that is a non-axial parabolic mirror provided in the first region and a reflective mirror that is a non-axial parabolic mirror provided in the second region. The condenser mirror reflects the incident parallel light and collects it at the focal point of the condenser mirror, and the reflecting mirror is arranged so that the focal point of the reflective mirror is located at the focal point of the condenser mirror. The collected light may be reflected as parallel light, and the second detection position may be provided on the first optical path.

  The second detection position may be provided between the focal point and the reflecting mirror.

  A plurality of second detection positions may be provided corresponding to a plurality of first optical paths.

  A drive mechanism that moves the detector from one detection position to another detection position among a plurality of detection positions including the first detection position and the second detection position may be further provided.

  You may further provide the flow-path pipe | tube provided in an analysis area | region and letting a sample pass. The channel tube extends in a direction intersecting the first optical path and the second optical path, and the drive mechanism may move the detector in the direction in which the channel tube extends.

  The light source may include a light emitting diode that emits ultraviolet light.

  According to the analyzer of the present invention, the apparatus can be miniaturized.

It is a figure which shows the analyzer in embodiment. It is a figure which shows the optical path formed of a reflection mechanism.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

  FIG. 1 shows an analyzer 100 according to the embodiment, and FIG. 2 shows an optical path formed by the reflection mechanism 30. The analysis apparatus 100 irradiates a sample such as a gas passing through the flow channel tube 20 with light from the light source 10, and detects the light irradiated on the sample with the detector 40, thereby determining the component and concentration of the substance contained in the sample. analyse. The analyzer 100 includes a reflection mechanism 30 configured by a plurality of non-axial parabolic mirrors 31 to 35 provided on both sides of the flow channel tube 20 so that light from the light source 10 is repeatedly straddled through the flow channel tube 20. The light is reflected in a zigzag shape and is incident on the detector 40. The detector 40 is movable along the flow channel tube 20, and by arranging the detector 40 at any one of the plurality of detection positions 40a to 40c, an appropriate optical path according to the sample to be measured. Select the length.

  The analysis device 100 includes a light source 10, a collimating lens 12, a flow channel tube 20, a reflection mechanism 30, a detector 40, a drive mechanism 50, and a control unit 60. The reflection mechanism 30 includes a plurality of non-axis parabolic mirrors 31 to 35.

  The light source 10 emits measurement light for irradiating a sample to be analyzed. The light source 10 is a light emitting diode (LED), and is, for example, an ultraviolet LED that emits ultraviolet light having a central wavelength or peak wavelength in the ultraviolet region of about 200 nm to 350 nm. As such an ultraviolet light LED, for example, one using aluminum gallium nitride (AlGaN) is known. In this embodiment, an ultraviolet LED having a peak wavelength of 285 nm is used.

By using an ultraviolet light source as the light source 10, sulfur dioxide (SO ₂ ), nitric oxide (NO), nitrogen dioxide (NO ₂ ), chlorine (Cl ₂ ), ammonia (NH ₃ ), carbonyl sulfide (COS), sulfide Gases such as hydrogen (H ₂ S) can be analyzed. Further, by using the LED as the light source 10, the apparatus can be downsized and the power consumption can be reduced as compared with the case of using an ultraviolet lamp or the like. The light emitted from the light source 10 is adjusted to parallel light by the collimating lens 12.

  The channel tube 20 is a tube through which a sample such as a gas passes in the longitudinal direction X, and defines an analysis region C3 that is a space in which a sample to be analyzed exists. The shape of the channel tube 20 is not particularly limited as long as it has a tube shape such as a cylindrical shape or a prismatic shape. A plurality of windows 24 that transmit light from the light source 10 are provided on the side wall 22 of the flow channel tube 20. The window 24 is provided at a position where the optical paths provided in a zigzag shape by the reflection mechanism 30 intersect. The window 24 is made of a material having a high transmittance of light from the light source 10, and is made of, for example, quartz or sapphire having a high transmittance of ultraviolet light. As a modification of the channel tube 20, instead of providing the window 24, the side wall 22 may be made of quartz, sapphire, or the like having a high ultraviolet light transmittance.

  The reflection mechanism 30 includes a plurality of non-axial parabolic mirrors 31 to 35 disposed on both sides of the flow channel tube 20, and reciprocates in the analysis region C 3 where the measurement light from the light source 10 is partitioned by the flow channel tube 20. Thus, a zigzag optical path is formed. The non-axial parabolic mirrors 31 to 35 have reflecting surfaces made of aluminum (Al) having a high reflectivity for ultraviolet light. The light emitted from the light source 10 is emitted from the first non-axial parabolic mirror 31, the second non-axial parabolic mirror 32, the third non-axial parabolic mirror 33, the fourth non-axial parabolic mirror 34, and the fifth non-axial parabolic mirror 34. It is reflected in the order of the axial paraboloidal mirror 35 and heads for the detection position 40a at the end where the detector 40 is disposed.

  Among the plurality of non-axial parabolic mirrors 31 to 35, the first non-axial parabolic mirror 31, the third non-axial parabolic mirror 33, and the fifth non-axial parabolic mirror 35 are outside the analysis region C3. Provided in the first region C1. As shown in FIG. 2, the non-axial parabolic mirrors 31, 33, and 35 provided in the first region C1 reflect incident parallel light and pass through the analysis region C3 from the first region C1 to the second region. An optical path toward C2 (hereinafter also referred to as a first optical path) is formed, and the light is collected at focal points F1 to F3 provided on the first optical path. Therefore, the non-axial parabolic mirrors 31, 33, and 35 provided in the first region C1 function as a condensing mirror that collects light at the focal points F1 to F3.

  On the other hand, the second non-axial parabolic mirror 32 and the fourth non-axial parabolic mirror 34 are provided in the second region C2 facing the first region C1 across the analysis region C3. The non-axial parabolic mirrors 32 and 34 provided in the second region C2 form an optical path (hereinafter also referred to as a second optical path) from the second region C2 through the analysis region C3 to the first region C1. The light condensed at the focal points F1 and F2 on the first optical path is reflected as parallel light. Accordingly, the non-axial parabolic mirrors 32 and 34 provided in the second region C2 function as reflecting mirrors that reflect the light collected at the focal points F1 and F2 as parallel light.

The first non-axis parabolic mirror 31 is configured such that the rotationally symmetric axis of the paraboloid constituting the reflecting surface of the first non-axis parabolic mirror 31 is parallel to the optical axis of the light A ₀ from the light source 10. Be placed. Thereby, the light A ₀ from the light source 10 is incident in parallel to the rotational symmetry axis of the first non-axial parabolic mirror 31, and the light A ₁ reflected by the first non-axial parabolic mirror 31 is The first non-axial parabolic mirror 31 is focused on the first focal point F1.

The second non-axis parabolic mirror 32 is disposed so that the focal point of the second non-axis parabolic mirror 32 is located at the position of the first focal point F1. Thus, the light A ₁ focused on the first focus F1 is incident as light scattered to the second Hijikuho paraboloid mirror 32 to share the focal position from the focal point F1. Thus, the light A ₂ reflected by the second Hijikuho paraboloid mirror 32 is directed from the second region C2 as parallel light to the first area C1.

The third non-axis parabolic mirror 33 is arranged so that the rotationally symmetric axis of the paraboloid constituting the reflecting surface is parallel to the optical axis of the light A ₂ from the second non-axis parabolic mirror 32. . As a result, the light A ₂ from the second non-axial parabolic mirror 32 is incident parallel to the rotational symmetry axis of the third non-axial parabolic mirror 33 and is reflected by the third non-axial parabolic mirror 33. light a ₃ has is focused on the second focal point F2 of the third Hijikuho paraboloid mirror 33 has.

The fourth non-axis parabolic mirror 34 is arranged so that the focus of the fourth non-axis parabolic mirror 34 is located at the position of the second focal point F2. Thus, the light A ₃ condensed on the second focal point F2 is incident as light scattered to the fourth Hijikuho paraboloid mirror 34 to share the focal position from the focal point F2. Thus, the light A ₄ reflected by the fourth Hijikuho paraboloid mirror 34 is directed from the second region C2 as parallel light to the first area C1.

The fifth non-axis parabolic mirror 35 is arranged such that the rotationally symmetric axis of the paraboloid constituting the reflecting surface is parallel to the optical axis of the light A ₄ from the fourth non-axis parabolic mirror 34. . As a result, the light A ₄ from the fourth non-axis parabolic mirror 34 is incident parallel to the rotational symmetry axis of the fifth non-axis parabolic mirror 35 and is reflected by the fifth non-axis parabolic mirror 35. light a ₅ was is condensed to a third focal point F3 of the fifth Hijikuho paraboloid mirror 35 has.

  With the above configuration, the reflection mechanism 30 passes through the analysis region C3 from the first region C1 to the second region C2, and passes through the analysis region C3 from the second region C2 to the first region C1. A zigzag optical path is formed in which a plurality of second optical paths heading toward are formed.

In addition, in the reflection mechanism 30 of this Embodiment, the thing with the same off-axis angle and a focal distance is used as the some non-axis parabolic mirrors 31-35. For example, the values are an off-axis angle θ of 30 ° and a focal length of 50 mm. The angle formed by the incident light and the reflected light at each non-axis parabolic mirror is 2θ, which is twice the off-axis angle θ. The optical axes of the light beams A ₀ , A ₂ , and A ₄ that enter the object mirrors 31, 33, and 35 travel in parallel. Similarly, the optical axes of the light beams A ₁ , A ₃ , and A ₅ collected at the respective focal points F1 to F3 travel in parallel with each other.

  Further, since non-axial parabolic mirrors having the same focal length are used, the respective focal points F1 to F3 are located in the middle of the non-axial parabolic mirrors facing each other. As a result, the distance between the non-axial parabolic mirrors facing each other is twice the focal length. If the focal length of each non-axial parabolic mirror is 50 mm, the opposing non-axial parabolic mirrors are Arranged at intervals of 100 mm.

  The detector 40 is provided outside the analysis region C3 where the flow channel tube 20 is provided, and detects the intensity of light that has passed through the analysis region C3. The detector 40 is configured by a photodiode, a phototube, or the like, detects light incident on the incident port 42, and converts the intensity into an electric signal. The detector 40 is attached to a drive mechanism 50 extending in the longitudinal direction of the flow channel tube 20 and is movable in the longitudinal direction of the flow channel tube 20. The detector 40 can be disposed at a plurality of detection positions 40 a to 40 c by being attached to the drive mechanism 50.

  The plurality of detection positions 40a to 40c are provided on a first optical path which is on a zigzag optical path and travels from the first area C1 to the second area C2. Moreover, each detection position 40a-40c is provided in the position close | similar to the focus F1-F3 of the condensing mirror provided in 1st area | region C1. Specifically, the detection positions 40a to 40c are provided at positions where the distances from the focal points F1 to F3 are shorter than the focal lengths of the respective collecting mirrors. For example, when the focal length is 50 mm, the positions of the detection positions 40a to 40c are provided at positions 30 mm away from the focal point. By adopting such an arrangement relationship, it is possible to increase the measurement accuracy by making the high-intensity light collected by the condenser mirror incident on the detector 40.

First detection position 40a is arranged on the optical axis of the light A ₅ reflected by the fifth Hijikuho paraboloid mirror 35 is provided at the end of the zigzag optical path. Further, the first detection position 40a is disposed at a position where the distance from the third focal point F3 is shorter than the focal length of the fifth non-axial parabolic mirror 35. The first detection position 40a has a longer optical path length until it reaches the detection position through the analysis region C3 than the other detection positions 40b and 40c. Therefore, when the first detection position 40a is used when measuring a sample having a low concentration, the amount of light attenuation due to passing through the sample can be increased to increase the measurement accuracy.

The second detection positions 40b and 40c are provided in the middle of the zigzag optical path, and are arranged on the first optical path from the first area C1 to the second area C2. The second detection positions 40b and 40c are provided at a position between the focal point on the first optical path and the reflecting mirror provided in the second region C2. Specifically, the second detection position 40b provided in the first optical path where light A ₃ proceeds is provided at a position between the second focal point F2 and the fourth Hijikuho paraboloid mirror 34. The second detection position 40c provided in the first optical path of light A ₁ advances is provided at a position between the first focal point F1 and second Hijikuho paraboloid mirror 32.

  The second detection positions 40b and 40c have a shorter optical path length from the first detection position 40a to the detection position after passing through the analysis region C3. Therefore, even when measuring a sample having a high concentration or a sample having a high absorbance, it is possible to detect the measurement light before the light intensity is completely attenuated by the measurement light passing through the sample. Thus, by providing the second detection positions 40b and 40c in the middle of the optical path, an appropriate optical path length can be selected depending on the sample to be analyzed, and as a result, the measurable range can be expanded. .

  The drive mechanism 50 moves the detector 40 so that the detector 40 can be arranged at a plurality of detection positions 40a to 40c. The drive mechanism 50 includes, for example, a mechanism using a stepping motor and a lead screw, a belt mechanism, a linear motor mechanism, or the like. The drive mechanism 50 is provided extending in the longitudinal direction of the flow channel tube 20 and moves the detector 40 in the longitudinal direction of the flow channel tube 20. The drive mechanism 50 is electrically connected to the control unit 60 and is driven by a control signal from the control unit 60.

  The control unit 60 is electrically connected to the light source 10, the detector 40, and the drive mechanism 50, and controls these operations. The control unit 60 generates a signal for driving the light source 10 to emit measurement light from the light source 10, and acquires the intensity value of the measurement light detected by the detector 40 after passing through the analysis region C3. .

  When the light intensity value detected by the detector 40 is not within the predetermined range, the control unit 60 drives the drive mechanism 50 to move the position of the detector 40. For example, when the detector 40 is arranged at the first detection position 40a and the detected light intensity is less than a predetermined threshold, the detector 40 is set to one of the second detection positions 40b and 40c. Move to. On the other hand, when the detector 40 is arranged at the second detection positions 40b and 40c and the detected light intensity exceeds a predetermined threshold, the detector 40 is moved to the first detection position 40a. As described above, the control unit 60 controls the position of the detector 40 so that an appropriate optical path length is selected according to the detected light intensity.

  With the above-described configuration, the analyzer 100 can measure the absorbance of the sample existing in the analysis region C3 using the optical path configured in a zigzag shape. Since the optical path is formed in a zigzag shape, the analyzer 100 can be downsized compared to a case where optical paths having the same optical path length are linearly arranged. Further, in the analyzer 100, by forming the optical path in a zigzag shape, a plurality of detection positions provided in the middle of the optical path can be arranged on a straight line. Thereby, the optical path length of measurement light can be changed only by moving one detector 40 linearly. Therefore, in the analyzer 100, the optical path length of the measurement light can be changed without increasing the number of detectors 40, and the apparatus can be downsized as compared with the case where a plurality of detectors 40 are used.

  In addition, since the analysis apparatus 100 uses an ultraviolet LED as the light source 10, the apparatus can be downsized as compared with the case of using a high-output ultraviolet lamp or the like, and the power consumption of the light source 10 can be reduced. it can. Moreover, in the analyzer 100, while measuring light is condensed with a non-axis parabolic mirror, the detector 40 is arrange | positioned in the position where measurement was condensed. For this reason, even when the light source 10 having a low light emission intensity is used, the light intensity at the detection position can be increased, and a decrease in measurement accuracy can be suppressed. Thereby, the apparatus can be miniaturized while maintaining the measurement accuracy.

  The present invention has been described based on the embodiments. It is understood by those skilled in the art that the present invention is not limited to the above-described embodiment, and various design changes are possible, and various modifications are possible, and such modifications are within the scope of the present invention. It is a place.

In the present embodiment, the case where the light source 10 is configured by the ultraviolet LED is shown.
The light source 10 may be composed of a plurality of LEDs having different center wavelengths or peak wavelengths. For example, by combining a plurality of ultraviolet LEDs having different center wavelengths or peak wavelengths, it is possible to select a UV LED that emits light having an optimum wavelength according to the sample to be analyzed, and measure the sample. Further, the light emitted from the LED to be combined is not limited to ultraviolet light, and an LED that emits visible light or infrared light may be combined. In this case, the control part 60 is good also as analyzing the component and density | concentration of a sample by switching LED to light-emit according to the sample used as analysis object, and acquiring the intensity | strength of measurement light for every wavelength.

  In the present embodiment, the case where the light source 10 is configured by an ultraviolet LED has been described. However, the light source 10 may use a light source other than the LED, or a laser light source such as a laser diode.

  In the present embodiment, the case where the characteristics of the plurality of non-axial parabolic mirrors 31 to 35 are made the same has been shown. However, the non-axial parabolic mirrors having different off-axis angles and focal lengths are used in combination. Also good. For example, a non-axial parabolic mirror provided in the first region C1 and used as a condensing mirror adopts a long focal length, and a non-axial parabolic mirror provided in the second region C2 and used as a reflecting mirror. Adopt a short focal length. By selecting such a non-axial paraboloidal mirror, the focal position can be brought close to the detection position, and the light that is collected more strongly can be detected by the detector 40.

  In the present embodiment, as shown in the drawing, the optical arrangement is such that the plurality of focal points F1 to F3 are located in the analysis region C3. However, in the modification, the plurality of focal points F1 to F3 are not the analysis region C3 but the second region. It is good also as a structure located in the area | region C2. For example, by narrowing the width of the channel tube 20 in the short direction, the channel tube 20 is provided at a position between the condenser mirror provided in the first region C1 and the plurality of focal points F1 to F3. . By setting it as such an arrangement | positioning, a detection position can be provided nearer to the focus F1-F3, and a measurement precision can be improved.

  In the present embodiment, the reflection mechanism 30 has five non-axial parabolic mirrors, but the number of non-axial parabolic mirrors is not limited to this, and in a modified example, the non-axial parabolic mirrors are used. It is good also as a structure which has only one mirror, or changing the number of return | turns of a zigzag optical path as a structure of three or seven or more. Further, the second detection position may not be provided depending on the number of turns of the zigzag optical path, the number of the second detection positions may be one, or three or more.

  In the present embodiment, the case where the analysis region C3 is partitioned by the flow channel pipe 20 is shown, but the analysis apparatus 100 may be configured not to include the flow path tube 20. In this case, the atmospheric gas existing around the analysis apparatus 100 becomes a sample to be analyzed, and the space that becomes the analysis region C3 includes a collecting mirror provided in the first region C1 and a plurality of detections provided in the second region C2. It becomes a space between positions.

  C1 ... first region, C2 ... second region, C3 ... analysis region, 10 ... light source, 12 ... collimating lens, 20 ... channel tube, 24 ... window, 30 ... reflection mechanism, 31 ... first non-axial paraboloid Mirror, 32 ... second non-axial parabolic mirror, 33 ... third non-axial parabolic mirror, 34 ... fourth non-axial parabolic mirror, 35 ... fifth non-axial parabolic mirror, 40 ... detector 40a, first detection position, 40b, 40c, second detection position, 50, drive mechanism, 60, control unit, 100, analyzer.

Claims (8)

A light source that emits light that strikes the analysis area where the sample is present;
A reflection mechanism that reflects light from the light source and passes through the analysis region;
A detector for detecting light that has passed through the analysis region;
With
The analyzer is characterized in that the reflection mechanism reflects light from the light source by a non-axial parabolic mirror. The reflection mechanism has a plurality of non-axial parabolic mirrors provided in a first region outside the analysis region and a second region facing the first region across the analysis region;
The plurality of non-axial parabolic mirrors include a first optical path from the first region through the analysis region to the second region, and from the second region through the analysis region to the first region. Forming a zigzag optical path with a plurality of second optical paths toward the region,
2. The detector can be disposed at at least one of a first detection position provided at an end of the zigzag optical path and a second detection position provided in the middle of the zigzag optical path. The analyzer described in 1. The reflection mechanism includes a condensing mirror that is a non-axial parabolic mirror provided in the first region, and a reflective mirror that is a non-axial parabolic mirror provided in the second region,
The condenser mirror reflects incident parallel light and focuses it on the focal point of the condenser mirror,
The reflecting mirror is arranged so that the focal point of the reflecting mirror is located at the focal position of the condensing mirror, and reflects the light collected at the focal point as parallel light,
The analyzer according to claim 2, wherein the second detection position is provided on the first optical path.   The analyzer according to claim 3, wherein the second detection position is provided between the focal point and the reflecting mirror.   The analyzer according to claim 3 or 4, wherein a plurality of the second detection positions are provided corresponding to the plurality of first optical paths.   The apparatus further comprises a drive mechanism for moving the detector from one detection position to another detection position among a plurality of detection positions including the first detection position and the second detection position. Item 6. The analyzer according to Item 5. Provided in the analysis region, further comprising a channel tube for passing the sample;
The flow path tube extends in a direction intersecting the first optical path and the second optical path;
The analyzer according to claim 6, wherein the drive mechanism moves the detector in a direction in which the flow channel tube extends.   The analysis apparatus according to claim 1, wherein the light source includes a light emitting diode that emits ultraviolet light.

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