TWM272088U - Gas concentration detection device - Google Patents

Description

M272088 IV. Creation Instructions (1) ^ [Technical Field to which the New Type belongs] This creation relates to a gas concentration detection device, especially a gas concentration detection device with high measurement stability. ΐίPrevious technology】 丨

According to the analysis of gas concentration (ηοη— | dispersive lnfrared, NDIR) using a non-divergent infrared analyzer is a commonly used method, and its principle is because different gas molecules have a fixed vibration energy level, so 2 gas molecules When an electromagnetic wave with a corresponding vibration level is received, the gas molecule y absorbs this energy, and its absorption is proportional to the presence of a specific molecule | I. Therefore, infrared analysis uses infrared light to pass through the body of the gas to be measured, and is used to measure the change in light intensity to identify the specific gas concentration in the gas to be measured. The structure of a conventional N DIR device, as shown in the first figure, includes a cavity | 10, and a reflective layer 12 is plated on the wall of the cavity 10, and the material of the reflective layer 12 is gold, silver or For infrared, one of the metals with high reflectivity is introduced into the gas to be measured through the vent 13 on the cavity, and an infrared light source 14 is provided at one end of the cavity 10, and the other of the cavity 1 A sensor is set at one end • 'This sensor 16 is also connected to a signal detection circuit 丨 8, the signal detection circuit 18 stores the relevant information of the gas to be detected, and then when the gas in the cavity When the concentration is in equilibrium with the external concentration of the cavity, the infrared source 4 emits a plurality of light rays 20 into the cavity 10, and is repeatedly reflected and measured by the reflection layer 12 to measure the gas absorption. After the table, the light rays 2 are received by the sensor 16 After the sensor 16 receives the light 20 and outputs a signal to the signal detection circuit 丨 8, the signal detection

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Fourth, the creation instructions (2) I

The output circuit 18 calculates the concentration of the measurement gas. I However, when the infrared sensor 16 receives a large angle of incident light, the center wavelength of the filter in the sensor will have a relatively large deviation. For a typical red 1 external sensor, the incident light is greater than 20 At the angle of incidence, the peak of the filter is shifted toward the short wavelength by about 40nm. This change is because the filter has a certain band width. As a result, part of the light that is not absorbed by the gas to be measured can enter the sensor, and another part of the light about the concentration of the gas to be measured is blocked, thereby reducing the signal. Strength, which reduces the accuracy of the measurement. _ In view of this, this creation aims at the above problems and proposes an accurate and stable gas concentration detection device to effectively solve the above problems. [New content] The main purpose of this creation is to provide a gas concentration detection device, which can effectively improve the accuracy of radon measurement. Another purpose of this creation is to provide a gas concentration detection device that filters the light at a part of the angle through the absorption layer, so that the sensor can focus on the receiving range, thereby improving the measurement accuracy. • According to this creation, a gas concentration detection device includes a cavity in which a gas to be measured is injected, and a reflection layer and an absorption layer are provided on the cavity wall in the cavity; A radiation light source is disposed at one end of the body and adjacent to the reflection layer. The radiation light source emits a plurality of first light rays into the body, and the first light rays are repeatedly reflected and reflected by the reflection layer of the cavity to form a second light. Light; and on the other end of the cavity and adjacent

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The jj absorption layer is provided with a sensing element, and the absorption layer in the cavity can absorb or block the second light corresponding to the sensing element, the angle of incidence of the person is greater than the critical angle, and the sensing element is receiving The second ray with an angle of incidence ranging from 0 degrees to a critical angle f degrees and outputs n and this sensing element is connected again-a computing device to receive this signal and convert it into spectral data to calculate the gas to be measured Its concentration. The following detailed description with specific examples and accompanying drawings will make it easier to understand the purpose, technical details, features, and functions of this creation. [Embodiment] A creative department proposes a gas concentration detection device. As shown in the second figure, it includes a cavity 22, which is provided with a vent hole 23, and the vent hole 23 is provided with- A transition piece (not shown), this filter allows only specific gas to be tested to pass through; then the outside gas is allowed to pass through this vent hole 23, and the external gas is filtered with the filter to allow the specific gas to be measured to enter this cavity A reflecting layer 24 and an absorbing layer 26 are respectively provided on the wall of the cavity 22 in the U, and the reflecting layer 24 is provided by electroplating, and the material of the reflecting core 2 is made of gold or nickel. And one of its mixtures, and the absorption layer 26 is provided by a coating method, and the material of the absorption layer 26 is a black paint; in addition, a radiation light source 28 is provided on the end of the cavity 2 2 and adjacent to the reflection layer 24. The radiation light source 28 is an infrared light source, and the radiation light 28 may be a light cup type light source, which can increase the efficiency of the light source, and then the radiation light source 28 emits a plurality of first light rays into the cavity 22,

M272088 IV. Creative instructions (4) The reflective layer 2 4 is repeatedly reflected and absorbed by the gas to be measured to convert to form a second light, and a sensing element 3Q is provided on the other end of the cavity 2 2 and adjacent to the absorption layer 26. The sensing element 30 is connected to a computing device 32. The absorbing layer 26 in the cavity 22 can absorb a second light having an incident angle greater than a critical angle. The angle of this angle is 20 degrees. The second light at 0 to 19 degrees is received by the sensing element 30. After receiving the second light, the sensing element 30 outputs a signal to the computing device 32, and the computing device 32 calculates the gas to be measured. concentration. In addition, a reference sensing element (not shown) can be added to the sensing element 30 to correct the accuracy of the comparison sensing element 30. • In addition, the setting method of the absorption layer 26 can also be set by sandblasting. As shown in the third figure, the figure is near the sensing element 30 and on the wall of the cavity 22 using the sandblasting method. The cavity wall of the cavity 22 is rubbed into a rough shape, so that the second light cannot be reflected on the absorbing element 26 to the sensing element 30, so as to filter and remove the second light with an incident angle between 20 and 90 degrees. In addition, a barrier method can be used instead of the absorption layer 26. Please refer to the fourth figure, which uses a fence 34 near the sensing element 30 and a ring wall on the cavity wall 2 'This fence 34 is provided with a perforation 36. This perforation 36 allows only the second light with an incident angle of 0 to 19 degrees to pass through to remove the second light with an incident angle of 30 to 90 degrees. This body concentration detection device is detecting At the time, such as measuring office or warm to = carbon monoxide content, inject outside air into the vent hole 23, so that the gas to be j through the filter into the cavity 22, after stabilization, the light source emits the first plurality of light out, Each first light is repeatedly reflected in the cavity 22 by the reflective layer 24 and absorbed by part of the energy of the gas to be measured, making the first light

M272088 4. Creation instructions (5) The light is converted into a second light, and the second light with an incident angle of 20 to 90 degrees is removed by filtering through the absorption layer 26, so that the sensing element 30 can receive the second light in the concentrated area. Firstly, by absorbing layer 26 in cavity 22, in this creation, the sensing element # 30 can receive the second light in a concentrated area, so that the sensing element 30 can improve the stability and accuracy of the measurement. The above-mentioned embodiment is only a preferred embodiment of this creation. By f, the characteristics of this creation will be described as an example. The purpose is to enable those skilled in the art to use the content of this creation and implement it accordingly. Limiting the implementation of this creation = two measures Any application of the same changes and modifications to the structure, shape, and spirit described in the scope of the patent application for this creation shall be included in the scope of this creation patent application. ❿

Page 9 M272088 Simple illustration of the drawing [Simplified illustration of the drawing] The first figure is a schematic diagram of a conventional technical section. The second picture is a schematic diagram of the creative section. The third figure is a schematic cross-sectional view of the sandblasted absorption layer. The fourth figure is a schematic cross-sectional view of the absorbing layer in the form of a fence. [Description of main component symbols]

Page 10 10 Cavity 12 Reflective layer 13 Ventilation hole 14 Infrared light source 16 Sensor 18 Signal detection circuit 20 Light 22 Cavity 23 Ventilation hole 24 Reflective layer 26 Absorption layer 28 Luminous source 30 Sensing element 32 Computing device 34 Fence 36 perforated

Claims (1)

M272088 V. Application for Patent Scope 1. A gas concentration detection device comprising: a cavity in which a gas to be measured is injected, and a reflection layer and an absorption layer on the cavity wall in the cavity; A radiation light source is disposed at one end of the cavity and adjacent to the reflective layer, and is used to emit a plurality of first light rays into the cavity, and the first light is repeatedly reflected by the reflective layer of the cavity and the measurement is performed. The gas absorbs and transforms to form a second light; a sensing element is disposed on the other end of the cavity and is adjacent to the absorbing layer, and the absorbing layer can make the incident angle corresponding to the sensing element larger than a boundary The second light is absorbed by the angle, and the sensing element receives the second light with an incident angle between 0 degrees and the critical angle angle and outputs a signal; and a computing device connected to the sensing element to receive the The signal is converted into a spectral data, and the degree of the gas to be measured is calculated. 2. The gas concentration debt measuring device according to item 1 of the scope of the patent application, wherein the absorption layer is a black paint. 3. If you apply for a patent Su Tuchu 1 gas suitable for the customer, the order reading device, the absorption layer is: the barrier, the barrier is provided with -perforation, to make the incident angle of 0 to 19 degrees The second light passes. ^ As described in item 1 of the patent application scope, the gas system detection device, wherein the absorption layer is provided by a coating method. 5. The gas system detection device as described in item 1 of the scope of patent application, wherein the absorption layer is provided by sandblasting. 6. The gas concentration detection device as described in item 丨 of the patent application scope, wherein the radiation light source is an infrared light source. M272088 5. Scope of patent application 7. The gas concentration detection device as described in item 1 of the scope of patent application, wherein the critical angle is 20 degrees. 8. The gas concentration detection device as described in item 1 of the scope of patent application, wherein the cavity is further provided with at least one vent hole. 9 _. The gas concentration detection device as described in item 8 of the scope of the patent application, wherein a filter is provided in the vent hole, and the filter allows only the gas to be measured to pass. 10. The gas concentration detection device as described in item 1 of the scope of patent application, wherein the gas system to be measured contains carbon dioxide, carbon monoxide and mixtures thereof. 11. The gas concentration detection device according to item 1 of the scope of the patent application, wherein the reflective layer is one of gold metal, nickel metal, and a mixture thereof. 12. The gas concentration detection device according to item 1 of the scope of patent application, wherein the reflective layer is provided by electroplating. 13. The gas concentration detection device according to item 1 of the scope of patent application, wherein the sensing element further includes a reference sensing element for correcting the accuracy of the comparison of the sensing element. Page 12