WAVELENGTH-MODULABLE SPECTRUM GENERATOR, AND SYSTEM AND METHOD FOR MEASURING CONCENTRATION OF GAS COMPONENT BASED THEREON

Abstract

The present invention discloses a wavelength-modulable spectrum generator as well as a system and method for measuring concentration of a gas component based thereon. The wavelength-modulable spectrum generator includes a filter plate, a to-be-measured gas box and a light intensity receiving plate. A plate surface of the filter plate is encircled with N filter holes, and a filter lens with a specific refractive index is correspondingly fixedly arranged in each filter hole. A light source mounting position is fixed to a side of an in-light surface of the filter plate. After any light source is mounted at the light source mounting position, lights of the light source irradiate the filter lens. A rotation and deflection driving mechanism is connected with an out-light surface of the filter plate and drives the filter plate to rotate or deflect along the axis according to a preset angle.

Claims

1. A wavelength-modulable spectrum generator, comprising a filter plate (1), wherein a plate surface of the filter plate (1) is encircled with N filter holes, and a filter lens (2) with a specific refractive index is correspondingly fixedly arranged in each filter hole; a light source mounting position (3) is fixed to a side of an in-light surface of the filter plate (1), and after any light source is mounted at the light source mounting position (3), lights of the light source irradiate the filter lens (2); a rotation and deflection driving mechanism (4) is connected with an out-light surface of the filter plate (1) and drives the filter plate (1) to rotate or deflect along the axis according to a preset angle.

2. The wavelength-modulable spectrum generator according to claim 1, wherein the rotation and deflection driving mechanism (4) comprises a universal joint (4a); the universal joint (4a) comprises sequentially connected first lever and second lever; the first lever of the universal joint (4a) is connected with the center of the out-light surface of the filter plate (1) while the second lever thereof is connected with a rotation driving shaft of a rotation driving motor (4d); a deflection driving shaft sleeve (4b) movably sleeves the first lever of the universal joint (4a); a hinge joint is arranged on the deflection driving shaft sleeve (4b) and is connected with a drive rod of a servomotor (4e); the rotation driving motor (4d) and the servomotor (4e) are arranged on a support frame (5).

3. The wavelength-modulable spectrum generator according to claim 2, wherein a horizontal deflection limit frame (4f) is also hinged between the deflection driving shaft sleeve (4b) and the support frame (5); the horizontal deflection limit frame (4f) comprises a first hinge block and a second hinge block; the first hinge block is fixed to the deflection driving shaft sleeve (4b); the second hinge block is fixed to the support frame (5), the second hinge block extends in a horizontal direction of the rotation driving shaft and then is hinged with the first hinge block, and the hinging axial line is in parallel with the deflection axial line of the deflection driving shaft sleeve (4b); the hinging axial line of the first hinge block and the second hinge block passes through a connection point of the first lever and the second lever of the universal joint (4a).

4. The wavelength-modulable spectrum generator according to claim 2, further comprising a controller (6), wherein a rotation driving end of the controller (6) is connected with the rotation driving motor (4d); a deflection driving end of the controller (6) is connected with the servomotor (4e); a deflection angle measuring end of the controller (6) is connected with an angle sensor (7) arranged in the servomotor (4e).

5. The wavelength-modulable spectrum generator according to claim 3, further comprising a controller (6), wherein a rotation driving end of the controller (6) is connected with the rotation driving motor (4d); a deflection driving end of the controller (6) is connected with the servomotor (4e); a deflection angle measuring end of the controller (6) is connected with an angle sensor (7) arranged in the servomotor (4e).

6. A system for measuring concentration of a gas component based on the wavelength-modulable spectrum generator according to claim 4, further comprising: a to-be-measured gas box (8) and a light intensity receiving plate (9), which are fixed to the first lever of the universal joint (4a), wherein the to-be-measured gas box (8) and the light intensity receiving plate (9) are sequentially arranged between the side of the out-light surface of the filter plate (1) and the deflection driving shaft sleeve (4b), and the filter plate (1), the to-be-measured gas box (8) and the light intensity receiving plate (9) are coaxially arranged and are mutually parallel; a box body of the to-be-measured gas box (8) is fabricated by a transparent material and is filled with a to-be-measured gas; a light intensity measurement film (9a) is arranged on the light intensity receiving plate (9) and is connected with a gas measurement input end of the controller (6).

7. A system for measuring concentration of a gas component based on the wavelength-modulable spectrum generator according to claim 5, further comprising: a to-be-measured gas box (8) and a light intensity receiving plate (9), which are fixed to the first lever of the universal joint (4a), wherein the to-be-measured gas box (8) and the light intensity receiving plate (9) are sequentially arranged between the side of the out-light surface of the filter plate (1) and the deflection driving shaft sleeve (4b), and the filter plate (1), the to-be-measured gas box (8) and the light intensity receiving plate (9) are coaxially arranged and are mutually parallel; a box body of the to-be-measured gas box (8) is fabricated by a transparent material and is filled with a to-be-measured gas; a light intensity measurement film (9a) is arranged on the light intensity receiving plate (9) and is connected with a gas measurement input end of the controller (6).

8. A measurement method based on the system for measuring concentration of a gas component according to claim 6, specifically comprising the following steps: S1: presetting a type of a to-be-measured gas, a required type of a spectrum and a corresponding wavelength of the spectrum, mounting a light source corresponding to the type of the spectrum, and acquiring a thickness L of a to-be-measured gas box (8); S2: according to the type of the spectrum and the corresponding wavelength of the spectrum, comprehensively selecting a filter lens (2) to obtain a refractive index n and a thickness d of the fiber lens, and also obtaining an incidence angle of the light source on an in-light surface of the filter lens and an initial light intensity I.sub.0 after the light source passes through the corresponding filter lens; S3: controlling the rotation driving motor (4d) to rotate by the controller (6) such that the light source irradiates the filter lens (2) with the corresponding refractive index n; S4: controlling the servomotor (4e) to drive extension by the controller (6) such that the deflection driving shaft sleeve (4b) pulls the first lever of the universal joint (4a) to deflect an angle along a lever joint; S5: acquiring an out-put light intensity I.sub.v measured by the light intensity measurement film (9a) by the controller (6); S6: according to the initial light intensity I.sub.0 and the out-put light intensity I.sub.v, calculating the concentration c of a component of the to-be-measured gas (8) in the to-be-measured gas box in combination with the beer-lambert law.

9. A measurement method based on the system for measuring concentration of a gas component according to claim 7, specifically comprising the following steps: S1: presetting a type of a to-be-measured gas, a required type of a spectrum and a corresponding wavelength of the spectrum, mounting a light source corresponding to the type of the spectrum, and acquiring thickness L of a to-be-measured gas box (8); S2: according to the type of the spectrum and the corresponding wavelength of the spectrum, comprehensively selecting a filter lens (2) to obtain a refractive index n and thickness d of the fiber lens, and also obtaining an incidence angle of the light source on an in-light surface of the filter lens and an initial light intensity I.sub.0 after the light source passes through the corresponding filter lens; S3: controlling the rotation driving motor (4d) to rotate by the controller (6) such that the light source irradiates the filter lens (2) with the corresponding refractive index n; S4: controlling the servomotor (4e) to drive extension by the controller (6) such that the deflection driving shaft sleeve (4b) pulls the first lever of the universal joint (4a) to deflect an angle along a lever joint; S5: acquiring an out-put light intensity I.sub.v measured by the light intensity measurement film (9a) by the controller (6); S6: according to the initial light intensity I.sub.0 and the out-put light intensity I.sub.v, calculating the concentration c of a component of the to-be-measured gas (8) in the to-be-measured gas box in combination with the beer-lambert law.

10. The measurement method based on the system for measuring concentration of a gas component according to claim 8, wherein in step S2, an incident angle of the light source is obtained by calculating according to formula (1): $\begin{array}{cc}=\frac{2.Math.\mathrm{nd}.Math..Math.\cos \left[\arcsin \left(\frac{\sin .Math.}{n}\right)\right]}{m};& \left(1\right)\end{array}$ wherein m is a constant; d is the thickness of the filter lens; and $0<<\frac{}{2}.$

11. The measurement method based on the system for measuring concentration of a gas component according to claim 9, wherein in step S2, an incident angle of the light source is obtained by calculating according to formula (1): $\begin{array}{cc}=\frac{2.Math.\mathrm{nd}.Math..Math.\cos \left[\arcsin \left(\frac{\sin .Math.}{n}\right)\right]}{m};& \left(1\right)\end{array}$ wherein m is a constant; d is the thickness of the filter lens; and $0<<\frac{}{2}.$

12. The measurement method based on the system for measuring concentration of a gas component according to claim 8, wherein step S6 of calculating the concentration c of a component according to the initial light intensity I.sub.0 and the out-put light intensity I.sub.v utilizes the following formula:
I.sub.v=I.sub.0 exp [a(v)cL](2); wherein a(v) is an attenuation coefficient, and L is the thickness L of the box body of the to-be-measured gas box (8).

13. The measurement method based on the system for measuring concentration of a gas component according to claim 9, wherein step S6 of calculating the concentration c of a component according to the initial light intensity I.sub.0 and the out-put light intensity I.sub.v utilizes the following formula:
I.sub.v=I.sub.0 exp [a(v)cL](2); wherein a(v) is an attenuation coefficient, and L is the thickness L of the box body of the to-be-measured gas box (8).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG. 1 is a first schematic structural diagram of a wavelength-modulable spectrum generator of the present invention.

[0044] FIG. 2 is a second schematic structural diagram of a wavelength-modulable spectrum generator of the present invention.

[0045] FIG. 3 is a schematic structural diagram of a first embodiment of a filter plate according to the present invention.

[0046] FIG. 4 is a schematic structural diagram of a second embodiment of a filter plate according to the present invention.

[0047] FIG. 5 is a schematic diagram showing a mounting structure of a to-be-measured gas box and a light intensity receiving plate according to the present invention.

[0048] FIG. 6 is a schematic diagram showing mounting and irradiating of a light source according to the present invention.

[0049] FIG. 7 is a control block diagram of a system for measuring concentration of a gas component of the present invention.

[0050] FIG. 8 is a flowchart of a method for measuring concentration of a gas component of the present invention.

[0051] FIG. 9 is a diagram showing the principle of refraction in the present invention.

[0052] FIG. 10 is a schematic diagram of a Fabry-Perot interferometer.

[0053] FIG. 11 is a schematic diagram showing influence on wavelengths by changes of an incidence angle of a light after the light passes through the filter lens.

[0054] FIG. 12 is a schematic diagram showing influence on wavelengths by changes of the refractive index of a filter lens.

[0055] In the figures, 1. filter plate 2. filter lens 3. light source mounting position 4. rotation and deflection driving mechanism 5. support frame 6. controller 7. angle sensor 8. to-be-measured gas box 9. light intensity receiving plate 4a. universal joint 4b. deflection driving shaft sleeve 4d. rotation driving motor 4e. servomotor 4f. horizontal deflection limit frame

DETAILED DESCRIPTION

[0056] Specific embodiments and working principle of the present invention will be further described in detail with reference to the accompanying drawings.

[0057] As shown in FIG. 1 and FIG. 2, a wavelength-modulable spectrum generator includes a filter plate 1. A plate surface of the filter plate 1 is encircled with N filter holes, and a filter lens 2 with a specific refractive index is correspondingly fixedly arranged in each filter hole.

[0058] In an implementation, N=6. As shown in FIG. 1 to FIG. 3, the filter hole is circular.

[0059] In another implementation, N=6. As shown in FIG. 4, the filter hole is sector-shaped.

[0060] As shown in FIG. 1 and FIG. 6, a light source mounting position 3 is fixed to a side of an in-light surface of the filter plate 1. After any light source is mounted at the light source mounting position 3, lights of the light source irradiate the filter lens 2.

[0061] A rotation and deflection driving mechanism 4 is connected with an out-light surface of the filter plate 1 and drives the filter plate 1 to rotate or deflect along the axis according to a preset angle.

[0062] In the embodiment, with reference to FIG. 1, FIG. 2 and FIG. 5, the rotation and deflection driving mechanism 4 includes a universal joint 4a. The universal joint 4a includes sequentially connected first lever and second lever. The first lever of the universal joint 4a is connected with the center of the out-light surface of the filter plate 1 while the second lever thereof is connected with a rotation driving shaft of a rotation driving motor 4d.

[0063] With reference to FIG. 4, a deflection driving shaft sleeve 4b movably sleeves the first lever of the universal joint 4a. A hinge joint is arranged on the deflection driving shaft sleeve 4b and is connected with a drive rod of a servomotor 4e. With reference to FIG. 1 and FIG. 2, the drive rod includes a deflection pull rod and a servomotor arm, one end of the defection pull rod is connected with a ball end of the hinge joint of the deflection driving shaft sleeve 4b while the other end thereof is connected with a ball end of one end of the servomotor arm. The other end of the servomotor arm is connected with a drive output end of the servomotor 4e. Through matching of the deflection pull rod and the servomotor arm, when the servomotor 4e rotationally drives one end of the servomotor arm to rotate by taking the other end of the servomotor arm as the center in the shape of an arc, the deflection pull rod is driven to move in a direction of the arc. Therefore, one end of the deflection pull rod pulls the hinge point such that the deflection drive shaft sleeve 4b sleeving the first lever of the universal joint 4a drives the first lever to deflect in a plane vertical to the arc. The arc rotation needs a certain flexibility, so a ball-end connection is utilized to prevent mutual blockage.

[0064] Where the principle of using the servomotor 4e to drive the deflection driving shaft sleeve 4b to deflect is widely applied in the prior art, such as to wheel steering of an automobile, a mechanical arm and the like, and the structure is simple and easy to understand, which are not described in the present invention.

[0065] In the embodiment, with reference to FIG. 1 and FIG. 2, the rotation driving motor 4d and the servomotor 4e are arranged on a support frame 5.

[0066] With reference to FIG. 1, FIG. 2 and FIG. 5, a horizontal deflection limit frame 4f is also hinged between the deflection driving shaft sleeve 4b and the support frame 5.

[0067] The horizontal deflection limit frame 4f includes a first hinge block and a second hinge block.

[0068] The first hinge block is fixed to the deflection driving shaft sleeve 4b.

[0069] The second hinge block is fixed to the support frame 5. The second hinge block extends in a horizontal direction of the rotation driving shaft and then is hinged with the first hinge block. The hinging axial line is in parallel with the deflection axial line of the deflection driving shaft sleeve 4b.

[0070] In the embodiment, with reference to FIG. 5, the hinging axial line of the first hinge block and the second hinge block passes through a connection point of the first lever and the second lever of the universal joint 4a.

[0071] In the embodiment, with reference to FIG. 7, to achieve intelligent control, the wavelength-modulable spectrum generator further includes a controller 6. A rotation driving end of the controller 6 is connected with the rotation driving motor 4d. A deflection driving end of the controller 6 is connected with the servomotor 4e. A deflection angle measuring end of the controller 6 is connected with an angle sensor 7 arranged in the servomotor 4e.

[0072] With reference to FIG. 1 and FIG. 6, a system for measuring concentration of a gas component based on the wavelength-modulable spectrum generator further includes a to-be-measured gas box 8 and a light intensity receiving plate 9, which are fixed to the first lever of the universal joint 4a. The to-be-measured gas box 8 and the light intensity receiving plate 9 are sequentially arranged between the side of the out-light surface of the filter plate 1 and the deflection driving shaft sleeve 4b. The filter plate 1, the to-be-measured gas box 8 and the light intensity receiving plate 9 are coaxially arranged and are mutually parallel.

[0073] In the embodiment, a box body of the to-be-measured gas box 8 is fabricated by a transparent material and is filled with a to-be-measured gas. Furthermore, an air inlet and an air outlet are arranged on the to-be-measured gas box 8 and are used for feeding and discharging the gas. In the embodiment, a thickness of the box body of the to-be-measured gas box 8 is L.

[0074] To measure the light intensity of a spectrum after lights pass through the to-be-measured gas box 8, a light intensity measurement film 9a is arranged on the in-light surface of the light intensity receiving plate 9. With reference to FIG. 7, the light intensity measurement film 9a is connected with a gas measurement input end of the controller 6.

[0075] With reference to FIG. 8, a measurement method based on the system for measuring concentration of a gas component includes the following steps:

[0076] S1: preset a type of a to-be-measured gas, a required type of a spectrum and a corresponding wavelength of the spectrum, mount a light source corresponding to the type of the spectrum, and acquire the thickness L of a to-be-measured gas box 8;

[0077] S2: according to the type of the spectrum and the corresponding wavelength of the spectrum, comprehensively select a filter lens 2 to obtain a refractive index n and a thickness d of the fiber lens, and also obtain an incidence angle of the light source on an in-light surface of the filter lens and an initial light intensity I.sub.0 after the light source passes through the corresponding filter lens;

[0078] With reference to FIG. 9, refraction is generated when a light irradiates from one medium to another medium. An incidence angle .sub.1 and an exit angle has a relationship:

n.sub.1.Math.sin .sub.1=n.sub.2.Math.sin (1);

[0079] where the refractive index in vacuum is 1, namely n=150

[00003]$\begin{array}{cc}n.Math..Math.1=\frac{\sin .Math..Math.{}_1}{\sin .Math..Math.}& \left(2\right)\end{array}$

[0080] If the same monochromatic light propagates in different mediums, its wavelength is different because of different frequencies. If .sub.1 is used for representing the wavelength of the light in vacuum and n.sub.2 represents the refractive index of the medium, the wavelength or the speed v of the light in the medium is

[00004]$\begin{array}{cc}{}^{}=\frac{{}_1}{n_2}.Math..Math.\mathrm{or}.Math..Math.v=\frac{c}{n_2}& \left(3\right)\end{array}$

[0081] With reference to FIG. 10 which is a schematic diagram of a Fabry-Perot interferometer, when the light passes through a filter lens with the medium n and the thickness d, it can be known that the speed or the wavelength is changed according to formula (3), so an optical path difference of transmitted lights is as follows:

[00005]$\begin{array}{cc}=n\left(A.Math.B+B.Math.C\right)-\mathrm{CD}.Math..Math.\mathrm{where}.Math..Math..Math.\mathrm{AB}=\mathrm{BC}=\frac{d}{\cos .Math..Math.}.Math..Math.\mathrm{CD}=\mathrm{AC}.Math..Math.\sin .Math..Math..Math..Math.A.Math..Math.C=.Math.2.Math..Math.d.Math.\tan .Math..Math.,.Math.\mathrm{so}.Math..Math.\mathrm{CD}=2.Math.d.Math.\tan .Math..Math..Math.\sin .Math..Math.& \left(4\right)\end{array}$

[0082] Based on formula (2), it can be known

[00006]$n=\frac{\sin .Math.}{\sin .Math..Math.}$

[0083] If the above equation is substituted into (4), it can be obtained

=2nd cos (5)

[0084] So an m-level bright fringe of the Fabry-Perot interferometer (F-P interferometer) is:

=2nd cos =m(6)

[0085] namely

[00007]$\begin{array}{cc}=\frac{2.Math.\mathrm{nd}.Math..Math.\cos .Math..Math.}{m}& \left(7\right)\end{array}$

[0086] (2) and (7) are simultaneous to obtain

[00008]$\left(\right)=\frac{2.Math.\mathrm{nd}.Math..Math.\cos \left[\arcsin \left(\frac{\sin .Math.}{n}\right)\right]}{m}$

[0087] where m is a constant representing the m-level bright fringe of the Fabry-Perot interferometer; d represents the thickness of the filter lens; and

[00009]$0<<\frac{}{2}.$

[0088] In the embodiment,

[00010]$=\frac{2.Math.\mathrm{nd}.Math..Math.\cos \left[\arcsin \left(\frac{\sin .Math..Math.{}_i}{n}\right)\right]}{m},=\min \left[{}_i\right],$

i=1, 2, 3, 4, 5, and 6.

[0089] S3: control the rotation driving motor 4d to rotate by the controller 6 such that the light source irradiates the filter lens 2 with the corresponding refractive index n;

[0090] S4: control the servomotor 4e to drive extension by the controller 6 such that the deflection driving shaft sleeve 4b pulls the first lever of the universal joint 4a to deflect an angle along a lever joint;

[0091] S5: acquire an out-put light intensity I.sub.v measured by the light intensity measurement film 9a by the controller 6;

[0092] S6: according to the initial light intensity I.sub.0 and the out-put light intensity I.sub.v, calculate the concentration c of a component of the to-be-measured gas in the to-be-measured gas box 8 in combination with the beer-lambert law.

[0093] According to the initial light intensity I.sub.0 and the out-put light intensity I.sub.v, the concentration c of a component utilizes the following formula:

I.sub.v=I.sub.0 exp [a(v)cL];

[0094] where a(v) is an attenuation coefficient which is set by querying a table in the embodiment. L is the thickness L of the box body of the to-be-measured gas box 8.

[0095] By taking the wavelength as a dependent variable and the incidence angle as an independent variable, a functional image as shown in FIG. 11 is drawn. Referring to FIG. 11, when the incidence angle is changed from

[00011]$\frac{}{2}$

to 0, the wavelength is also increased.

[0096] Similarly, by taking as a dependent variable and the refractive index n as an independent variable, a functional image as shown in FIG. 12 is drawn. Referring to FIG. 12, when the refractive index is n>1, the wavelength is increased along with the increasing the refractive index.

[0097] In the present invention, the filter plate 1, the to-be-measured gas box 8 and the light intensity receiving plate 9 are arranged in parallel, and 6 filter lenses 2 are arranged on the plate surface of the filter plate 1. The filter plate 1 is controlled to rotate such that the light source passes through different filter mediums. In combination with the servomotor 4e and the deflection driving shaft sleeve 4b, the universal joint 4a is pulled to deflect. The light source is not changed, but a currently arranged direction of the filter plate 1 is changed such that the light source deflects in a horizontal direction in FIG. 1 so as to change the incident angle of the light source. The specific wavelength is obtained by changing a medium, through which a spectrum passes and an incident angle of the spectrum. By utilizing the system of the present invention, the specific wavelengths of different spectrums can be obtained; a range of wavelengths to be modulated is large; a modulation procedure is easy; the structure is simple; an objective of testing various samples can be achieved without the need of changing the device; the application range is wide.

[0098] It should be noted that the above description is not intended to limit the present invention, and the present invention is not limited to the above embodiments. Changes, modifications, additions or replacements made by those ordinary skill in the art within the essential range of the present invention should fall within the protection scope of the present invention.