Sensing device for detecting gas concentration and use method thereof

Abstract

The invention relates to the technical field of sensors, and provides a sensing device for detecting gas concentration and a use method thereof.The sensing device for detecting gas concentration comprises a testing cavity, a data reader and a comparator, the inner wall of the testing cavity is connected with a photoelectric detector and a light source, the photoelectric detector and the light source are oppositely arranged, and the data reader is connected with the comparator; the test cavity is provided with an air inlet hole, to-be-tested gas can enter the test cavity through the air inlet hole, and the photoelectric detector is used for detecting corresponding photocurrent signals before and after the to-be-tested gas is injected; the data reader is respectively communicated with the photoelectric detector and the comparator; the data reader is used for carrying out noise reduction processing and amplification processing on the light current signal and then converting the light current signal into a light intensity electric signal; and the comparator is used for comparing the light intensity electric signal with a stored database and outputting the concentration and the safety level of the gas to be detected. By using the sensing device, the problems of large volume, high cost, complex detection process and the like of a toxic and harmful gas detection device in industrial production can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and particularly to a sensing device for detecting gas concentration and its usage method. Background Art

[0002] In the fields of industry and manufacturing, gas sensors play a crucial role, especially in detecting combustible gases and toxic gases. With the rapid development of industrialization and urbanization, environmental pollution problems have become increasingly serious. In particular, the toxic and harmful gases emitted by industries pose a great threat to people's health and the ecological environment. Therefore, the development and innovation of gas sensor technology are particularly important.

[0003] Currently, the commonly used gas sensors in industry / manufacturing mainly include semiconductor sensors, catalytic combustion sensors, electrochemical sensors, infrared sensors, etc.

[0004] Semiconductor sensors mainly utilize the adsorption of gas by metal oxide semiconductor materials and the principle of conductivity change at a specific temperature for detection. Such sensors have the advantages of low cost, simple manufacturing, high sensitivity, fast response speed, etc., and have been widely used in combustible gas leakage detection devices in homes and factories. However, semiconductor sensors also have some disadvantages, such as the need to work at high temperatures, poor selectivity to gases or odors, and unsatisfactory stability, which limit their application in high-precision detection.

[0005] Catalytic combustion sensors utilize the chemical reaction of combustible gases on catalytic elements, resulting in temperature changes on the surface and inside of the sensor carrier, thereby completing the sensing process. This type of sensor has the advantages of good linear output signal, reliable index, low price, and no cross-interference with other non-combustible gases, and is widely used in combustible gas monitoring equipment in industrial and civil fields. However, catalytic combustion sensors can only measure combustible gases, have limitations, and in some extreme environments, such as high-concentration corrosive gas or high-humidity environments, their performance may be affected. Summary of the Invention

[0006] The purpose of the present invention is to solve the problems of large volume, high cost, and complex detection process of toxic and harmful gas concentration detection devices in existing industrial production, and to provide a sensing device for detecting gas concentration and its usage method.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is:

[0008] A sensing device for detecting gas concentration, comprising a test chamber, a data reader and a comparator. The inner wall of the test chamber is connected with a photodetector and a light source. The photodetector is arranged opposite to the light source. The test chamber is provided with an air inlet, and the gas to be measured can enter the test chamber through the air inlet. The photodetector is used to detect the corresponding photocurrent signals before and after injecting the gas to be measured.

[0009] The data reader is respectively connected to the photodetector and the comparator. The data reader is used to perform noise reduction processing and amplification processing on the photocurrent signal and then convert it into a light intensity electrical signal. The comparator is used to compare the light intensity electrical signal with the stored database and output the concentration and safety level of the gas to be measured.

[0010] A sensing device for detecting gas concentration adopted in the present invention. Using the photodetector as the detection element of the gas detection sensing device has high sensitivity, can detect extremely low-concentration gases, and can also achieve real-time monitoring and rapid detection. By detecting the change of the optical signal, the gas concentration is measured. There is no need for complex chemical or electrochemical reactions, the operation is simple, and there is no need to directly contact the gas, which can improve the safety during the detection of industrial combustible gases and toxic gas leaks, and can also prevent the sensing device from being contaminated and damaged, extending the service life of the sensing device. Using the photodetector can also selectively detect gas types, reduce the interference of other gases on the detection result, and improve the accuracy of the detection result. The photodetector usually has a compact structure, is convenient to be integrated into portable devices, is suitable for application scenarios with limited space, and the manufacturing process of the photodetector is relatively simple, and the material cost is low, which is suitable for large-scale production and application.

[0011] As a preferred solution of the present invention, the photodetector is a perovskite photodetector with a gradually changing bandgap.

[0012] The gradually changing bandgap structure enables it to absorb light of different wavelengths, improving the detection ability for various gases. The perovskite material has high light absorption coefficient and carrier mobility characteristics, improving the detection sensitivity of the sensing device, and can be used for low-concentration gas detection.

[0013] As a preferred solution of the present invention, the perovskite component of the photodetector is CH3NH3Pb(I x Br 1-x Cl 1-y )3, where x, y < 1, and x + y < 1.

[0014] As a preferred solution of the present invention, the test chamber is further provided with a micro air pump, and the micro air pump is used to inject the gas to be measured into the test chamber.

[0015] As a preferred embodiment of the present invention, the micro air pump is a remotely controllable air pump.

[0016] As a preferred embodiment of the present invention, the interior of the test chamber is in a negative pressure state, and when in use, the gas to be measured can enter the test chamber through the pressure difference between the inside and outside of the test chamber.

[0017] As a preferred embodiment of the present invention, it further includes an alarm, and the alarm is connected to the comparator. The alarm is used to give an alarm prompt according to the air quality result.

[0018] The present invention also provides a method for using a sensing device for detecting gas concentration, including using a sensing device for detecting gas concentration as described above, and the steps are as follows:

[0019] S1. Open the test chamber, inject ambient background gas, turn on the light source, and the photodetector detects and outputs a first photocurrent signal corresponding to before injecting the gas to be measured, and outputs the first photocurrent signal to the data reader.

[0020] S2. Select the type of gas to be measured on the comparator, open the test chamber, and inject the gas to be measured.

[0021] S3. The photodetector detects and outputs a second photocurrent signal corresponding to after injecting the gas to be measured, and outputs the photocurrent signal to the data reader.

[0022] S4. The data reader receives the first photocurrent signal and the second photocurrent signal, performs noise reduction processing and amplification processing, and converts them into light intensity electrical signals.

[0023] S5. The comparator receives and calculates the change value A between the light intensity electrical signals of the photodetector before and after injecting the gas to be measured. n Compare the change value A n with the database in the comparator to obtain the concentration of the gas to be measured and the safety level corresponding to this concentration, and output the gas concentration result and the safety level.

[0024] The method for using a sensing device for detecting gas concentration adopted by the present invention only needs to measure the change in photocurrent before and after injecting the gas to be measured, without complex chemical reactions or sample pretreatment, and the detection process is simple and fast; by comparing with the standard photocurrent-gas concentration mapping data in the database, the gas type and concentration can be automatically identified, reducing human error; the photodetector is small in size, low in power consumption, and easy to be integrated into portable devices, suitable for on-site detection or mobile applications.

[0025] As a preferred embodiment of the present invention, the specific processing steps in step S5 are as follows:

[0026] S51. Calculate the change value A between the optical intensity electrical signals of the photodetector before and after injecting the gas to be measured in sequence. n ;

[0027] S52. Compare the change value A n with a number of standard change values I in the database corresponding to the selected type of gas to be measured in sequence n and output the volume concentration of the gas to be measured of the change value A n and the safety level corresponding to the volume concentration.

[0028] As a preferred solution of the present invention, when the safety level is level one or two in step S52, the alarm does not give an alarm prompt; when the safety level is level three or four in step S52, the alarm gives an alarm prompt.

[0029] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are:

[0030] 1. A sensing device for detecting gas concentration, using a photodetector as the detection element of the gas detection sensing device has very high sensitivity, can detect gas at extremely low concentrations, and can also achieve real-time monitoring and rapid detection; the gas concentration is measured by detecting the change of the optical signal, without complex chemical or electrochemical reactions, and the operation is simple.

[0031] 2. A method for using a sensing device for detecting gas concentration, only needs to measure the change of the photocurrent before and after injecting the gas to be measured, without complex chemical reactions or sample pretreatment, and the detection process is simple and fast; by comparing with the standard photocurrent-gas concentration mapping data in the database, the gas type and concentration can be automatically identified, reducing human error; the photodetector is small in size and low in power consumption, and is easy to be integrated into portable devices, suitable for on-site detection or mobile applications. Description of the Drawings

[0032] Figure 1 is a schematic structural connection diagram of a sensing device for detecting gas concentration;

[0033] Figure 2 is a schematic connection diagram inside the test chamber of a sensing device for detecting gas concentration;

[0034] Figure 3 is a flowchart of the method for using a sensing device for detecting gas concentration;

[0035] Reference Signs: 1 - Test Chamber; 11 - Photodetector; 12 - Light Source; 13 - Air Inlet Hole; 14 - Micro Air Pump; 2 - Data Reader; 3 - Comparator; 4 - Alarm. Detailed Embodiments

[0036] The present invention will be described in detail below with reference to the accompanying drawings.

[0037] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0038] Embodiment 1

[0039] As Figure 1 shown, a sensing device for detecting gas concentration adopted by the present invention includes a test chamber 1, a data reader 2 and a comparator 3. An optoelectronic detector 11 and a light source 12 are connected to the inner wall of the test chamber 1. The optoelectronic detector 11 and the light source 12 are arranged opposite to each other. The test chamber 1 is provided with an air inlet hole 13, and the gas to be measured can enter the test chamber 1 through the air inlet hole 13. The optoelectronic detector 11 is used to detect the corresponding photocurrent signals before and after injecting the gas to be measured;

[0040] The data reader 2 is respectively connected to the optoelectronic detector 11 and the comparator 3; the data reader 2 is used to perform noise reduction processing and amplification processing on the photocurrent signal and then convert it into a light intensity electrical signal. The comparator 3 is used to compare the light intensity electrical signal with the stored database and output the concentration and safety level of the gas to be measured.

[0041] Further, the optoelectronic detector 11 is a perovskite optoelectronic detector 11 with a gradually changing bandgap.

[0042] Further, the perovskite component of the optoelectronic detector 11 is CH3NH3Pb(I x Br 1-x Cl 1-y )3, where x, y < 1 and x + y < 1.

[0043] Further, the test chamber 1 is also provided with a micro air pump 14, and the micro air pump 14 is used to inject the gas to be measured into the test chamber 1.

[0044] Further, the micro air pump 14 is a remotely controllable air pump.

[0045] Further, the inside of the test chamber 1 is in a negative pressure state, and when in use, the gas to be measured can enter the test chamber 1 through the pressure difference inside and outside the test chamber 1.

[0046] Further, it further includes an alarm 4. The alarm 4 is connected to the comparator 3, and the alarm 4 is used to give an alarm prompt according to the air quality result.

[0047] As Figure 2As shown, in this embodiment, the graded bandgap component of the photodetector 11 is CH3NH3Pb(I x Br 1- x Cl 1-y )3, where x, y < 1 and x + y < 1. The micro air pump 14 is arranged on the side opposite to the air inlet hole 13. Using the photodetector 11 as the detection element of the gas detection sensing device has high sensitivity, can detect extremely low concentrations of gas, and can also achieve real-time monitoring and rapid detection; the gas concentration is measured by detecting the change of the optical signal, without complex chemical or electrochemical reactions, is easy to operate, and does not need to directly contact the gas, which can improve the safety during the detection of industrial combustible gas and toxic gas leakage, and can also avoid the contamination and damage of the sensing device, and prolong the service life of the sensing device.

[0048] Embodiment 2

[0049] As Figure 3 shown, a method for using a sensing device for detecting gas concentration adopted by the present invention includes using a sensing device for detecting gas concentration as described in Embodiment 1, and the steps are as follows:

[0050] S1. Open the test chamber 1, inject ambient background gas, turn on the light source 12, the photodetector 11 detects and outputs a first photocurrent signal corresponding to before injecting the gas to be detected, and output the first photocurrent signal to the data reader 2;

[0051] S2. Select the type of gas to be detected on the comparator 3, open the test chamber 1, and inject the gas to be detected;

[0052] S3. The photodetector 11 detects and outputs a second photocurrent signal corresponding to after injecting the gas to be detected, and output the photocurrent signal to the data reader 2;

[0053] S4. The data reader 2 receives the first photocurrent signal and the second photocurrent signal, performs noise reduction processing and amplification processing, and converts them into optical intensity electrical signals;

[0054] S5. The comparator 3 receives and calculates the change value A n between the optical intensity electrical signals of the photodetector 11 before and after injecting the gas to be detected, compares the change value A n with the database in the comparator 3 to obtain the concentration of the gas to be detected and the safety level corresponding to the concentration, and outputs the gas concentration result and the safety level.

[0055] Further, the specific processing steps in step S5 are as follows:

[0056] S51. Calculate the change value A between the optical intensity electrical signals of the photodetector 11 before and after injecting the gas to be measured in sequence. n ;

[0057] S52. Compare the change value A n with a number of standard change values I in the database corresponding to the selected type of gas to be measured in sequence n and output the volume concentration of the gas to be measured corresponding to the change value A n and the safety level corresponding to the volume concentration.

[0058] Further, when the safety level in step S52 is level one or two, the alarm 4 does not give an alarm prompt; when the safety level in step S52 is level three or four, the alarm 4 gives an alarm prompt.

[0059] In this embodiment, at a place far from the industrial gas storage, open the air inlet hole 13 and start the micro air pump 14 to ensure that the background gas enters the test chamber 1 through the air inlet hole 13; then, turn on the light source 12, and the photodetector 11 measures and outputs the first photocurrent signal corresponding to before injecting the gas to be measured; transfer the sensing device to the place where the industrial gas is stored, select the type of the gas to be measured on the comparator 3, open the air inlet hole 13 and start the micro air pump 14 to inject the gas to be measured into the test chamber 1, and the photodetector 11 outputs the second photocurrent signal corresponding to after injecting the gas to be measured; transmit the first photocurrent signal and the second photocurrent signal to the data reader 2, and the first photocurrent signal and the second photocurrent signal are processed by noise reduction and amplification to obtain the optical intensity electrical signal, and the comparator 3 receives and calculates the change value A between the optical intensity electrical signals corresponding to before and after injecting the gas to be measured n , and compare the change value A n with the set of standard change thresholds {I n} corresponding to the selected type of the gas to be measured in the database in sequence and output the volume concentration of the gas to be measured corresponding to the change value A n and the safety level corresponding to the volume concentration.

[0060] When the output safety level is level one or two, the alarm 4 does not give an alarm prompt; when the safety level output in step S52 is level three or four, the alarm 4 gives an alarm prompt.

[0061] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A sensing device for detecting gas concentration, characterized in that, It includes a test chamber, a data reader and a comparator. The inner wall of the test chamber is connected with a photodetector and a light source. The photodetector is arranged opposite to the light source. The test chamber is provided with an air inlet, and the gas to be measured can enter the test chamber through the air inlet. The photodetector is used to detect the photocurrent signals corresponding before and after injecting the gas to be measured. The data reader is respectively connected to the photodetector and the comparator. The data reader is used to perform noise reduction processing and amplification processing on the photocurrent signal and then convert it into a light intensity electrical signal. The comparator is used to compare the light intensity electrical signal with the stored database and output the concentration and safety level of the gas to be measured.

2. The sensing device for detecting gas concentration according to claim 1, wherein The photodetector is a perovskite photodetector with a gradually changing bandgap.

3. A sensing device for detecting gas concentration according to claim 2, characterized in that, The perovskite component of the photodetector is CH3NH3Pb(I x Br 1-x Cl 1-y )3, where x, y < 1 and x + y < 1.

4. A gas concentration detecting sensing device according to claim 1, characterized in that, The test chamber is also provided with a micro air pump, and the micro air pump is used to inject the gas to be measured into the test chamber.

5. A gas concentration detecting sensing device according to claim 4, characterized in that, The micro air pump is a remotely controllable air pump.

6. A gas concentration detecting sensing device according to claim 1, characterized in that, The inside of the test chamber is in a negative pressure state, and when in use, the gas to be measured can enter the test chamber through the pressure difference inside and outside the test chamber.

7. A gas concentration detecting sensing device according to any one of claims 1 to 6, characterized in that, It also includes an alarm, and the alarm is connected to the comparator. The alarm is used to give an alarm prompt according to the air quality result.

8. A method of using a sensing device for detecting gas concentration, characterized in that, It includes using a sensing device for detecting gas concentration according to any one of claims 1 to 7, and the steps are as follows: S1. Open the test chamber, inject ambient background gas, turn on the light source, the photodetector detects and outputs the first photocurrent signal corresponding before injecting the gas to be measured, and output the first photocurrent signal to the data reader. S2. Select the type of the gas to be measured on the comparator, open the test chamber, and inject the gas to be measured. S3. The photodetector detects and outputs the second photocurrent signal corresponding after injecting the gas to be measured, and output the photocurrent signal to the data reader. S4. The data reader receives the first photocurrent signal and the second photocurrent signal, performs noise reduction processing and amplification processing, and converts them into light intensity electrical signals. S5. The comparator receives and calculates the change value A between the optical intensity electrical signals corresponding to before and after injecting the gas to be measured, n , and compares the change value A n with the database in the comparator to obtain the concentration of the gas to be measured and the safety level corresponding to this concentration, and outputs the gas concentration result and the safety level.

9. The method of using a sensing device for detecting gas concentration according to claim 8, characterized in that, The specific processing steps in step S5 are as follows: S51. Calculate the change value A between the optical intensity electrical signals of the photodetector before and after injecting the gas to be measured in sequence n ; S52. Take the change value A n and compare it successively with several standard change values I in the database corresponding to the selected types of gases to be measured n and output the volume concentration of the gas to be measured of the change value A n and the safety level corresponding to the volume concentration.

10. The method of using a sensing device for detecting gas concentration according to claim 9, characterized in that, When the safety level in step S52 is level one or two, the alarm does not give an alarm prompt; when the safety level in step S52 is level three or four, the alarm gives an alarm prompt.

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