KR20180097493A - Apparatus for measuring gas concentration - Google Patents

Abstract

Disclosed is an apparatus for measuring a gas concentration. The apparatus for measuring a gas concentration comprises: a light source unit for irradiating light into the apparatus for measuring a gas concentration; an incident unit for refracting the light emitted from the light source unit; a first reflector for reflecting the incident light; a third rotary reflector; and a light reception unit for measuring light quantity of the incident light. The light incident from the incident unit is reflected by the first reflector through a third reflector, and an optical path changes as the third reflector rotates, and is incident on the light reception unit. Further, the present invention controls rotation of the third reflector to extend the length of the optical path of the light incident into the apparatus for measuring a gas concentration.

Description

[0001] APPARATUS FOR MEASURING GAS CONCENTRATION [0002]

The present invention relates to a gas concentration measuring apparatus and, more particularly, to a gas concentration measuring apparatus capable of precisely measuring a gas concentration and reducing the size of a gas by extending a light path length for measuring a gas concentration using a plurality of reflectors.

Optical gas sensor technologies are based on the assumption that gases composed of different atoms (eg, CO, CO ₂ , CH ₄ , NO, NO ₂ , SO ₂ , NH ₃ and acetone) absorb light of a specific wavelength band , Which is a method of measuring the gas concentration by measuring the light absorption rate of the gas by wavelength and converting it into the light absorption rate.

Since the light absorptance of the gas will be proportional to the gas concentration, accurate measurement of the light absorption rate of the gas is the key to the optical gas sensor. Therefore, an optical gas sensor basically includes a light source and a photodetector, and has a structure including an optical cavity for increasing a light absorption rate.

The mechanism by which gas molecules absorb light is as follows. In general, gas molecules constitute various energy levels, and by absorbing photons with energetic energy at these energy levels, the gas molecules transit from the ground state to the excited state.

Gas molecules selectively absorb only the energy corresponding to each of the vibration energy, and absorb the light of the infrared region as vibration energy. For this reason, CO ₂ , CO, CH ₄ and C ₃ H ₈ have a unique absorption spectrum. For example, CO ₂ absorbs a wavelength of 4.25 μm, CO ₄ .7 μm, CH ₄ absorbs a wavelength of 3.3 μm, The degree of absorption depends on the concentration of the gas.

This light absorption rate differs depending on the gas molecules. For example, carbon dioxide (Carbon Dioxide) has a high light absorptance so as to be designated as a greenhouse gas, but Carbon Monoxide has a low light absorption rate. The absorption rate of photons is defined as the absorption rate per molecule. In general, the gas sensor for detecting a gas having a high absorption rate is technically difficult, and the gas sensor for detecting a gas having a low absorption rate is technically difficult.

However, even with a gas with a low absorption rate, the absorption rate increases when the number of photons and gas molecules can be increased. One of the ways to increase the number of contacts of gas molecules for the same amount of light is to increase the optical path length in the optical cavity, which is confirmed from the Beer-Lambert theory of optical gas sensor interpretation theory. .

In the Beer-Lambert theory, the amount of light detected by the photodetector in the absence of gas molecules is I _o , the concentration of gas in X, the length of the optical path in which the light contacts the gas from the light source to the photodetector is L, Providing the relationship between gas concentration and I, the amount of light reaching the photodetector (see below), when b is the natural absorption rate.

I = I _o exp (-bLX)

From the Beer-Lambert theory, it can be seen that as the optical path length L increases, the I value becomes smaller for the same concentration, and as the optical path length L increases for the same concentration change, the variation width of the I value becomes larger, .

On the other hand, an effective optical cavity must have a structure for increasing the light efficiency in addition to lengthening the optical path. In general, since the light emitted from the light source is radiated in all directions, a considerable amount of light is wasted without contributing to the detection of the gas concentration. However, if the light collecting characteristic of the optical cavity is increased, the amount of light to be wasted can be reduced, thereby increasing the light efficiency.

As can be seen from the above expression, the larger the I _o value is, the higher the light efficiency is, and since the variation of the I value is large with respect to the same concentration change, it is also possible to manufacture a more precise sensor. In conclusion, it can be said that the competitiveness of the optical type gas sensor is determined by increasing the length of the optical path, making the size smaller and increasing the light efficiency.

KR 10-1256381 B1 US 8749789 B2

SUMMARY OF THE INVENTION It is an object of the present invention to provide a gas concentration measuring apparatus capable of accurately measuring a gas concentration and downsizing it by extending a light path length for measuring a gas concentration using a plurality of reflectors .

According to an aspect of the present invention, there is provided an apparatus for measuring a gas concentration according to an embodiment of the present invention, including: a light source section for irradiating light into the gas concentration measuring apparatus; an incident section for refracting light emitted from the light source section; And a light receiving portion for measuring a light amount of the incident light, wherein light incident from the incident portion is incident on the first reflector through the third reflector, And is reflected between the reflector and the second reflector. As the third reflector rotates, the optical path changes and is incident on the light receiver.

Advantageously, the light reflected from the first reflector and the light reflected from the second reflector can pass through the same point.

Preferably, each of the first reflector, the second reflector, and the third reflector may be any one of an ellipse, a mirror, a pipe, and a plane mirror.

Also preferably, the focal point of the first reflector and the focal point of the second reflector may be located on the reflection surface of the third reflector.

Preferably, the first reflector is a plane mirror, and the gas concentration measuring device further comprises a light-converging lens disposed between the first reflector and the second reflector.

Also preferably, the focal point of the light-converging lens may be located on the reflecting surface of the third reflector.

The gas concentration measuring apparatus may further comprise a control unit for controlling the incident angle of light irradiated to the inside of the gas concentration measuring apparatus to be different from each other in accordance with the wavelength of the light irradiated into the gas concentration measuring apparatus have.

Also, preferably, the light source unit may include a plurality of optical elements for emitting light having different incident angles and different wavelengths.

Preferably, the incident portion may further include an optical dispersion compensator that minimizes dispersion of the wavelength of the light emitted from the light source portion.

Preferably, the first reflector and the second reflector are formed of a single mirror, and the focal points of the first reflector and the second reflector may coincide with each other.

Preferably, the gas concentration measuring apparatus further includes a gas concentration measuring unit for measuring a gas concentration in the gas concentration measuring apparatus, And a control unit for rotating the three mirrors.

The gas concentration measuring apparatus according to the present invention as described above has the effect of accurately measuring the gas concentration and reducing the size by extending the optical path length for measuring the gas concentration using a plurality of reflectors.

1A to 1C are views showing an apparatus for measuring a gas concentration according to an embodiment of the present invention.
2A to 2C are views showing a gas concentration measuring apparatus according to another embodiment of the present invention.
3 is a view showing a gas concentration measuring apparatus according to another embodiment of the present invention.
4 is a view showing an apparatus for measuring a gas concentration according to another embodiment of the present invention.
5 is a view showing a gas concentration measuring apparatus according to another embodiment of the present invention.
6A to 6C are views showing a gas concentration measuring apparatus according to another embodiment of the present invention.
7 is a perspective view showing a gas concentration measuring apparatus according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. For convenience of explanation, the infrared gas concentration measuring apparatus will be described as an example. However, the present invention is not limited to the infrared gas concentration measuring apparatus, and can be applied to a gas concentration measuring apparatus using a light source other than infrared rays.

The thickness of the lines and the size of the elements shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

Figs. 1A to 1C are views showing a gas concentration measuring apparatus according to an embodiment of the present invention, and are cross-sectional side views.

1A, a gas concentration measuring apparatus 100 according to an embodiment of the present invention includes a light source 110, an incident unit 120, a light receiving unit 130, a chamber unit 150, a first reflector 160, A second reflector 170, and a third reflector 180.

The light source unit 110 can irradiate light into the gas concentration measuring apparatus 100 by an applied power source. That is, the light source unit 110 can irradiate light to the incident unit 120 at a certain angle. The angle at which the light source unit 110 irradiates the light may be set such that the light that is emitted into the chamber unit 150 through the incident unit 120 is directed to the focal point F of the second reflector 170. The light irradiated from the light source unit 110 is incident on the incident unit 120 in consideration of the wavelength of the light source used for measuring the gas concentration by taking advantage of the property that the incident angle and the refraction angle of the light are different due to the difference in refractive index of different materials according to Snell's law, Can be set. The refraction angle shown in Fig. 1A is illustrative and not restrictive.

The light source unit 110 may include at least one of an infrared light emitting diode, an infrared lamp, and an ultraviolet lamp. Further, the light source unit 110 may further include a separate light condensing device for irradiating light in parallel at a predetermined angle.

The incident part 120 refracts the light emitted from the light source part 110 as shown in FIG. 1A, and directs the light to the third reflector 180. In order to reduce the loss of light, the incident portion 120 may be formed of a material having a high light transmittance. In addition, the incident portion 120 may be made of a material with a low dispersion according to wavelength.

The curvature of the incident portion 120 is set such that the distance from one side of the incident portion 120 to the focus F is defined as a radius of curvature with respect to the focus F as a curvature of the first reflector 160, It can also be designed as a polygon that is part of a circle. The incident portion 120 may have the same area as the first reflector 160, but the present invention is not limited thereto. The area and thickness of the incident portion 120 may be variously changed according to the design. The incidence part 120 may seal the inside of the chamber part 150 so that the gas introduced into the chamber part 150 does not flow out to the outside.

On the other hand, when the wavelength band of light used is narrow, that is, when light of a specific wavelength band such as a laser is used, the distance from the first reflector 160 to the focus F, the distance between the second reflector 170 and the focus F And the thickness of the incident portion 120 can be designed so that the destructive interference of light does not occur based on the wavelength of the light to be used.

The light receiving unit 130 may measure the amount of light incident on the light source unit 110 and passing through the chamber unit 150. The light-receiving unit 130 may be implemented by various types of light quantity measuring apparatuses known to those of ordinary skill in the art.

The chamber part 150 may be formed as a hollow enclosure through which gas can be introduced and discharged. The chamber portion 150 may include a gas inlet 151, a gas outlet 152, and a light outlet 153. The gas may be introduced through the gas inlet 151 formed in the chamber part 150 and the injected gas may be discharged to the outside through the gas outlet 152. According to the embodiment, the gas inlet 151 is provided with a dust removing filter, a moisture removing filter, etc. to remove foreign matter from the gas to be injected, thereby improving the measurement accuracy of the gas. As shown in FIG. 1A, the gas inlet 151 and the gas outlet 152 may each include a blocking membrane that operates in a sliding manner to prevent leakage of gas.

The light outlet 153 may be formed on one side of the chamber part 150 so that light can reach the light receiving part 130 from the chamber part 150. In order to reduce the loss of light, the light outlet 153 may be made of a material having a high transmittance. For convenience, the light outlet 153 is shown on one side of the second reflector 170 in FIG. 1A, but is not limited thereto. The positions of the gas inlet 151, the gas outlet 152, and the light outlet 153 may be formed at various positions according to the design.

The first reflector 160 can be designed as a pupil diameter that is a part of a circle whose radius is a distance from one side of the first reflector 160 to the focus F about the focal point F. [ To reduce the loss of light, the first reflector 160 may be composed of a material having a high reflectance of light and may be further coated to increase reflectivity. Light incident vertically onto the first reflector 160 passing through the focus F according to the nature of light is vertically reflected and directed to the focus F. [ According to an embodiment, the first reflector 160 may be attached to the inside of the chamber part 150 as shown in FIG. 1A.

The second reflector 170 can be designed as a pupil diameter that is a part of a circle whose radius is a distance from one side of the second reflector 170 to the focus F about the focal point F. [ In order to reduce the loss of light, the second reflector 170 may be made of a material having a high reflectance of light and may be further coated to increase the reflectance. Light incident perpendicularly to the second reflector 170 passing through the focus F according to the nature of light is vertically reflected to be directed to the focus F. [ According to an embodiment, the second reflector 170 may be attached to the inside of the chamber part 150 as shown in FIG. 1A. The distance from the first reflector 160 to the focus F and the distance from the second reflector 170 to the focus F may be variously changed according to the embodiment.

The gas concentration measuring apparatus 100 according to an embodiment of the present invention may direct the light reflected from the first reflector 160 and the light reflected from the second reflector 170 to the third reflector 180. As an example, light reflected from the first reflector 160 and light reflected from the second reflector 170 can pass through the same point. That is, the focus F toward which the light reflected from the first reflector 160 is directed and the focus F toward which the light reflected from the second reflector 170 are directed may be formed at the same point. For example, the focal point F of the first reflector 160 and the focus F of the second reflector 170 may be positioned on the reflective surface of the third reflector 180.

The third reflector 180 may be connected to a driving unit (not shown) that rotates the third reflector 180. In order to reduce the loss of light, the third reflector 180 may be formed of a material having a high reflectance of light. In an embodiment of the present invention, the driving unit rotates the third reflector 180 connected to the driving shaft by rotating the driving shaft by an applied power source, and may be a stepping motor, a DC motor, an induction motor, or the like Lt; / RTI > The drive shaft may be coupled to the center of the third reflector 180.

The gas concentration measuring apparatus 100 according to an embodiment of the present invention may further include a controller (not shown) for controlling the operation of the gas concentration measuring apparatus 100. The control unit may control the angle of the third reflector 180 so that the light reflected by the third reflector 180 faces the second reflector 170 when the control unit starts to irradiate the light for gas measurement.

1A, the light irradiated into the chamber part 150 through the incident part 120 may be reflected by the third reflector 180 located at the focus F and may be directed to the second reflector 170 . The controller controls the driving unit to rotate the third reflector 180 so that the angle of the third reflector 180 is adjusted so that the incident angle of the light incident on the third reflector 180 is 45 degrees, May be directed to the second reflector 170. In this case, However, this is an example, and the initial angle of the third reflector 180 is not limited thereto.

Referring to FIG. 1B, the light reflected by the second reflector 170 may be directed to the third reflector 180 located at the focus F, while the third reflector 180 may be directed by the control unit It can be rotated at a constant angle. The light reflected by the second reflector 170 may be reflected by the third reflector 180 and may be directed to the first reflector 160.

Next, referring to FIG. 1C, the light reflected by the first reflector 160 may be directed to the third reflector 180 and the focus F again. The controller controls the reflection angle of the light from the first reflector 160 toward the focus F by rotating the third reflector 180 so that the light reflected by the third reflector 180 located at the focus F is reflected by the light exit (153). That is, the light incident from the incident portion 120 can be reflected between the first reflector 160 and the second reflector 170 through the third reflector 180, and as the third reflector 180 rotates, The light path can be changed and incident on the light receiving unit 130. 1A through 1C, light incident through the incident portion 120 is incident on the third reflector 180, the second reflector 170, the third reflector 180, the first reflector 160, 180 and then reaches the light receiving unit 130 through the light outlet 153. However, the size of the chamber 150 and the rotation speed of the third reflector 180 may vary depending on the size of the chamber 150, The number of times the light incident into the unit 150 is reflected can be variously changed.

The control unit may control the rotation of the driving unit so as to adjust the path in which light is in contact with the gas. The controller according to an embodiment of the present invention can control the third reflector 180 to rotate at a constant speed, but the present invention is not limited thereto. That is, the control unit may control the rotation speed of the driving unit to be constant or irregularly.

The control unit 190 controls the light emitted from the gas concentration measuring apparatus 100 to pass through the light outlet 153 from the time when the light is incident on the chamber unit 150 inside the gas concentration measuring apparatus 100 The third reflector 180 can be rotated within a predetermined driving range until the time when the light is received by the light receiving unit 130. [ That is, the control unit 190 can rotate the driving unit clockwise or counterclockwise repeatedly within a constant driving range. In this case, the constant driving range may be selected from the angle of the third reflector 180, in which light reflected by the third reflector 180 is reflected toward the second reflector 170 without facing the light outlet 153. When rotating within a constant driving range, light may not travel on the same path between the first reflector 160 and the third reflector 180. The light from the first reflector 160 toward the focus F is reflected by the third reflector 180 and then reflected by the second reflector 170 so that the third reflector 180 This is because the angle of reflection at the third reflector 180 changes before and after the reflection at the second reflector 170.

In addition, the controller may adjust the length of the path in which light is in contact with the gas based on the time when the light is in contact with the gas. This is because the length of the optical path is related to the time required for light to enter the chamber part 150 through the incident part 120 and to exit through the light outlet 153. The distance between the first reflector 160 and the third reflector 180 is r1, the distance between the second reflector 170 and the third reflector 180 is r, And the thickness of the incident portion 120 is denoted by d, the optical path length L can be roughly expressed by the following equation.

 L = (c x t) x (r 1 + r 2 - d) / (r 1 + r 2)

The optical path may be slightly different depending on the length and material of the incident portion 120, and the relationship between the optical path and the measurement time is not limited to the above formula. Further, the controller may set the length of the optical path differently depending on the type of the gas to be measured. For example, when the concentration of the gas to be measured is high, the length of the optical path can be shortened, and when the concentration of the gas to be measured is low, the length of the optical path can be set long. Further, the longer the length of the optical path for the same concentration change, the more accurately the gas concentration can be measured. The controller adjusts the reflection angle of the light from the first reflector 160 toward the focus F by rotating the third reflector 180 after the set time according to the optical path length, And the light reflected by the third reflector 180 is directed toward the light outlet 153.

Meanwhile, the first reflector 160, the second reflector 170, and the third reflector 180 may be any one of elliptical, ellipsoidal, cylindrical, and planar. In FIG. 1, the first and second reflectors 160 and 170 are illustrated as a photoreceptor, which is a part of a circle having different radii centering on the focus F for convenience of illustration. However, the present invention is not limited thereto. An embodiment in which the first reflector 160 is a plane mirror will be described in detail with reference to FIGS. 2A to 2C, and a detailed description thereof will be omitted here.

2A to 2C are views showing a gas concentration measuring apparatus according to another embodiment of the present invention. 2A, a gas concentration measuring apparatus 200 according to another embodiment of the present invention includes a light source unit 210, an incident unit 220, a light receiving unit 230, a chamber unit 250, a first reflector 260 A second reflector 270, and a third reflector 280. As shown in FIG. The light source unit 210, the incidence unit 220, the light receiving unit 230, the chamber unit 250, the second reflector 270, and the third reflector 280 may be disposed on the light source 110, The light receiving unit 130, the chamber unit 150, the second reflector 170, and the third reflector 180, respectively, so that detailed description is omitted.

Referring to FIG. 2A, in the apparatus 200 for measuring a gas concentration according to another embodiment of the present invention, the first reflector 260 may have a planar view. The light from the first reflector 260 toward the focus F is reflected by the third reflector 280 and then reflected by the second reflector 270 so that the third reflector 280 The path of the light can be changed since the angle of reflection in the third reflector 280 changes before and after being reflected by the second reflector 270. [ The parallel incident light is condensed in the focus F and the light passing through the focus F is condensed in parallel to the first reflector 260 to correct the change in the path of the light directed to the first reflector 260 A condensing lens 254 facing the condensing lens 254 may be further included in the gas concentration measuring apparatus 200. [ The condenser lens 254 may be disposed between the first reflector 260 and the second reflector 270, and may be formed of a material having high transmittance. The focal point of the condenser lens 254 may be located on the reflective surface of the third reflector 280 and may be the same as the focus F of the first reflector 260 and the second reflector 270.

2A, the light irradiated into the chamber 250 through the incident portion 220 is reflected by the third reflector 280 located at the focus F after passing through the condenser lens 254 And may be directed to the second mirror 270.

2B, the light reflected by the second reflector 270 may be reflected by the third reflector 280 located at the focus F and may pass through the condenser lens 254, It is refracted by the light-converging lens 254 and can be incident on the first reflector 260 vertically. Since the third reflector 280 is rotated by the control unit by a predetermined angle while the light is reflected by the second reflector 270, the path of the light incident on the third reflector 280 from the incident portion 220, The path of the light reflected by the first reflector 280 and directed toward the first reflector 260 may be different from each other.

2C, the light reflected by the first reflector 260 may be refracted while passing through the condenser lens 254, and may be directed to the third reflector 280 and the focal point F. Referring to FIG. The control unit controls the reflection angle of the light from the first reflector 260 toward the focus F by rotating the third reflector 280 so that the light reflected by the third reflector 280 located at the focus F is reflected by the light exit (253).

Accordingly, the light receiving unit 230 can measure the amount of light incident on the light source unit 210 and passing through the chamber unit 250. The gas concentration measuring apparatus 200 according to another embodiment of the present invention further includes a controller (not shown) for controlling the operation of the gas concentration measuring apparatus 200 as described above with reference to Figs. 1A to 1C .

3 is a view showing a gas concentration measuring apparatus according to another embodiment of the present invention. 3, the gas concentration measuring apparatus 300 according to another embodiment of the present invention includes a light source unit 310, an incident unit 320, a chamber unit 350, and a first reflector 360 And may include a light receiving unit, a second reflector, a third reflector, and a control unit, not shown in FIG. 3, as described above with reference to FIGS. 1A to 2C. The incidence portion 320, the chamber portion 350 and the first reflector 360 may be similar to the incidence portion 120, the chamber portion 150, and the first reflector 160 described above with reference to FIG. 1A. Therefore, detailed explanation is omitted.

3, the gas concentration measuring apparatus 300 according to another embodiment of the present invention includes a plurality of optical elements 311 for irradiating light having different incident angles and different wavelengths to the light source unit 310 . 3, when the wavelength band of light used for gas measurement is wide, the refractive indices are different for each wavelength. Therefore, as shown in FIG. 3, the light source unit 310 includes optical elements 311 having different wavelength bands, The plurality of optical elements 311 may be arranged in an array. 3, each light emitted from the plurality of optical elements 311 may be differently refracted while passing through the incident portion 320 and travel toward the third reflector along the same optical path .

4 is a view showing an apparatus for measuring a gas concentration according to another embodiment of the present invention. 4, a gas concentration measuring apparatus 400 according to another embodiment of the present invention includes a light source unit 410, an incident unit 420, a chamber unit 450, and a first reflector 460 And may include a light receiving unit, a second reflector, a third reflector, a control unit, and the like as described above with reference to FIGS. 1A to 2C although not shown in FIG. The incidence portion 420, the chamber portion 450 and the first reflector 460 may be similar to the incidence portion 120, the chamber portion 150, and the first reflector 160 described above with reference to FIG. 1A. Therefore, detailed explanation is omitted.

The gas concentration measuring apparatus 400 according to another embodiment of the present invention may further include an incidence adjusting unit 413 so as to change an angle of irradiating light to the incidence unit 420 according to the wavelength of light to be used have. For example, the incidence adjustment unit 413 may be implemented as a rail, in which the light source unit 410 can move, as shown in FIG. In addition, according to the embodiment, the incident adjuster 413 can be changed into various shapes that can adjust the incident angle of the light emitted from the light source unit 410 to the incident unit 420.

The control unit can adjust the incident angle of the light irradiated into the gas concentration measuring apparatus 400 differently according to the wavelength of the light irradiated into the gas concentration measuring apparatus 400. As an example, the control unit may select a wavelength band of light suitable for measurement according to properties of a gas to be measured, and determine an incident angle so that the refraction angle at the incident portion becomes 90 degrees according to the refractive index of the wavelength band. The control unit controls the incident adjusting unit 413 according to the determined incident angle to adjust the incident angle of the light by rotating or moving the light source unit 410.

5 is a view showing a gas concentration measuring apparatus according to another embodiment of the present invention. 5, a gas concentration measuring apparatus 500 according to another embodiment of the present invention includes a light source unit 510, an incident unit 520, a chamber unit 550, and a first reflector 560 And may include a light receiving unit, a second reflector, a third reflector, a control unit, and the like as described above with reference to FIGS. 1A to 2C although not shown in FIG. The incidence portion 420, the chamber portion 450 and the first reflector 460 may be similar to the incidence portion 120, the chamber portion 150, and the first reflector 160 described above with reference to FIG. 1A. Therefore, detailed explanation is omitted.

The incident portion 520 of the gas concentration measuring apparatus 500 according to another embodiment of the present invention may further include an optical dispersion corrector 522 that minimizes the dispersion of the wavelength of the light emitted from the light source portion 510 . That is, the incident portion 520 may further include an optical dispersion correction portion 522 that minimizes dispersion of light, such as an achromatic prism, so that light of different wavelengths can be designed to be radiated toward the focal point F at the same refraction angle. 5, even when various wavelengths are mixed in the light emitted from the light source unit 510, or when the light emitted from the light source unit 510 is changed into various wavelengths, the light emitted from the light source unit 510 May be differently refracted according to wavelengths passing through the optical dispersion correction unit 522 and the incident unit 520, and may travel toward the third reflector along the same optical path.

6A to 6C are views showing a gas concentration measuring apparatus according to another embodiment of the present invention.

6A, a gas concentration measuring apparatus 600 according to another embodiment of the present invention includes a light source unit 610, an incident unit 620, a light receiving unit 630, a chamber unit 650, a gas inlet 651, A gas outlet 652, a light outlet 653, a first reflector 660, and a third reflector 680. The light source unit 610, the incidence unit 620, the light receiving unit 630 and the third reflector 680 may include the light source unit 110, the incident unit 120, the light receiving unit 130, the gas inlet 151, the gas outlet 152, the light outlet 153, and the third reflector 180, detailed description thereof will be omitted.

The gas concentration measuring apparatus 600 shown in FIG. 6A differs from the above-described embodiments in that the chamber portion 650 may be spherical in shape and circular in cross section. Accordingly, the first reflector 660 attached to the inside of the chamber part 650 may be formed as a part of one circumference.

That is, the gas concentration measuring apparatus 600 shown in FIG. 6A may be an embodiment in which the first reflector and the second reflector having the same focal point F in the above-described embodiments are formed into a single diameter.

6A, light irradiated into the chamber portion 650 through the incident portion 620 may be reflected by the third reflector 680 located at the focus F and may be directed to the first reflector 660 . Thereafter, the third mirror 680 may be rotated by a predetermined angle by the control unit.

6B, the light reflected by the first reflector 660 is reflected by the third reflector 680 located at the focus F again and is incident perpendicularly to the first reflector 660 have. Meanwhile, the third reflector 680 can be rotated by a predetermined angle by the control unit.

Next, referring to FIG. 6C, the light reflected by the first reflector 660 may be directed to the third reflector 680 and the focus F. FIG. The control unit rotates the third reflector 680 to adjust the reflection angle of the light from the first reflector 660 toward the focus F so that the light reflected by the third reflector 680 located at the focus F (653). Accordingly, the light-receiving unit 630 can measure the amount of light incident on the chamber unit 650 irradiated by the light source unit 610 and incident thereon.

6A to 6C, the light incident into the chamber portion 650 is reflected twice by the first reflector 660 and then exits to the light receiving portion 630 through the light outlet 653 for convenience of description. The number of times the light incident into the chamber 650 is reflected by the first reflector 660 varies depending on the rotation speed and the rotation angle of the third reflector 680 controlled by the controller, can be changed.

7 is a perspective view showing a gas concentration measuring apparatus according to another embodiment of the present invention. 7, an apparatus 700 for measuring gas concentration according to another embodiment of the present invention includes a light source 710, an incident portion 720, a light receiving portion 730, a first reflector 760, a second reflector 770 , A third reflector 780, and a base portion 790.

The gas concentration measuring apparatus 700 shown in FIG. 7 is a configuration in which the chamber section 150 is omitted in comparison with the gas concentration measuring apparatus 100 shown in FIG. 1, and includes a light source section 710 The incident portion 720, the light receiving portion 730, the first reflector 760, the second reflector 770, and the third reflector 780 may be combined. Accordingly, the gas concentration measuring apparatus 700 can measure the air state existing in the open space, the gas concentration in the air, and the like without requiring a separate gas inlet and gas outlet.

As shown in FIG. 7, the base 790 may be formed in a flat plate shape having a predetermined size, but is not limited thereto. The control unit (not shown) may include an incident unit 720, a light receiving unit 730, and a light receiving unit 730. The incident unit 720, the first reflector 760, the second reflector 770, and the third reflector 780 may be formed at a constant height. ), The driving unit of the third reflector 780, and the like.

The light incident from the light source unit 710 travels to the third reflector 780 through the incident unit 720 and the light reflected from the third reflector 780 travels through the second reflector 770 and the first reflector 760, And the light is emitted to the light receiving unit 730 according to the rotation of the third reflector 780 is similar to that described above with reference to FIG. 1 and so on, so that detailed description is omitted here.

Meanwhile, the controller according to an embodiment of the present invention may exist in the form of a single processor or a program for controlling the driving unit, the incident control unit, the gas inlet, and the gas outlet, but is not limited thereto. The control unit may exist in the form of a processor or a program for each of the driving unit, the incident adjusting unit 413, the gas inlet 151, and the gas outlet 152.

Meanwhile, the gas concentration measuring apparatus according to the present invention can be variously combined with the light source unit, the incident unit, the light receiving unit, the chamber unit, the first reflector, the second reflector, and the third reflector described in various embodiments as described above .

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (11)

A gas concentration measuring apparatus comprising:
A light source unit for irradiating light into the gas concentration measuring apparatus;
An incident portion for refracting the light emitted from the light source portion;
A first reflector for reflecting incident light;
A third rotatable mirror; And
And a light receiving portion for measuring the light amount of the incident light,
The light incident from the incidence portion is reflected by the first reflector through the third reflector, the optical path changes as the third reflector rotates, and is incident on the light receiving portion,
And the rotation of the third reflector is controlled to extend the length of the optical path of the light incident into the gas concentration measuring device. The method according to claim 1,
And the light reflected from the first reflector passes through the same point. 2. The display device according to claim 1, wherein each of the first reflector and the third reflector comprises:
An oval diameter, a diameter, a porosity, and a plane diameter. The method according to claim 1,
And the focal point of the first reflector is located on the reflection surface of the third reflector. The apparatus of claim 3, wherein the first reflector is a planar mirror,
Wherein the gas concentration measuring device comprises:
And a condenser lens disposed between the first reflector and the third reflector. 6. The method of claim 5,
And the focal point of the light-converging lens is located on the reflecting surface of the third reflector. The gas concentration measuring apparatus according to claim 1,
Wherein the gas concentration measuring apparatus further comprises a control unit for controlling an incident angle of light irradiated into the gas concentration measuring apparatus to be different from each other according to a wavelength of light irradiated to the interior of the gas concentration measuring apparatus. The light source unit according to claim 1,
And a plurality of optical elements for emitting light having different incident angles and different wavelengths. The apparatus according to claim 1,
Further comprising an optical dispersion correcting unit for minimizing dispersion of the wavelength of the light emitted from the light source unit. The light-emitting device according to claim 1,
Wherein the gas concentration measuring unit is formed of one of a plurality of gas measuring units. The gas concentration measuring apparatus according to claim 1,
And a control unit for rotating the third reflector in a constant driving range from a point of time when the light is irradiated into the gas concentration measuring apparatus to a point of time when the light irradiated into the gas concentration measuring apparatus exits to the light receiving unit Wherein the gas concentration measuring device comprises:

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