Gas concentration sensing apparatus and gas concentration measurement method

Abstract

A gas concentration sensing apparatus and a gas concentration measurement method. The gas concentration sensing apparatus comprises a sensor (100), a radio wave generator (200), and a signal processing module (300), wherein the radio wave generator (200) is electrically connected to a signal input end (101) of the sensor (100), and the signal processing module (300) is electrically connected to a signal output end (102) of the sensor (100); the sensor (100) comprises a quartz tuning fork (110) and a sensing micro-wire (120) that are electrically connected; the sensor (100) is used for having a gas to be measured introduced thereto, and allowing the sensing micro-wire (120) to absorb the gas to be measured; the radio wave generator (200) is used for emitting a vibrating radio wave to the sensor (100), such that the quartz tuning fork (110) and the sensing micro-wire (120) resonate upon receiving the vibrating radio wave, and transmitting a mechanical resonance signal to the signal processing module (300); and the signal processing module (300) is used for collecting the mechanical resonance signal and converting same into an electrical signal of a resonance frequency. In the solution, the characteristic that the overall resonance frequency of a quartz tuning fork (110) and a sensing micro-wire (120) changes with the concentration of a gas to be measured is used to directly obtain a corresponding concentration value of the gas to be measured, thereby achieving a simple and efficient measurement process.

Description

Gas concentration sensing device and gas concentration detection method Technical Field

[0001] This application relates to the field of gas detection technology, and in particular to gas concentration sensing devices and gas concentration detection methods. Background Technology

[0002] With the development of mixed gas concentration detection technology, especially hydrogen content detection technology, various sensors for detecting hydrogen content have emerged.

[0003] In related technologies, various sensors used to detect hydrogen content generally include metal oxide semiconductor hydrogen sensors, thermoelectric hydrogen-sensitive materials and sensors, optical hydrogen sensors, and electrochemical hydrogen sensors.

[0004] However, while metal oxide semiconductor hydrogen sensors are inexpensive and simple in structure, their general responsiveness to reducing gases leads to poor selectivity and insufficient sensitivity for practical applications. Thermoelectric hydrogen sensors, although offering better selectivity, are overly reliant on catalyst activity and are susceptible to catalyst poisoning. Optical hydrogen sensors suffer from poor durability, prone to delamination and blistering after repeated use. Electrochemical hydrogen sensors, while easily miniaturized, still have room for improvement in lifespan. Therefore, various sensors for hydrogen content detection in related technologies suffer from unsatisfactory detection performance.

[0005] Summary of the Invention

[0006] Therefore, it is necessary to address the problem of poor detection performance of various sensors used for monitoring hydrogen content in related technologies, and to provide a gas concentration sensing device and a gas concentration detection method.

[0007] On one hand, this application provides a gas concentration sensing device, which includes a sensor, an electromagnetic wave generator, and a signal processing module. The electromagnetic wave generator is electrically connected to the signal input terminal of the sensor, and the signal processing module is electrically connected to the signal output terminal of the sensor. The sensor includes an electrically connected quartz tuning fork and a sensing microfilament. When a gas to be measured is introduced into the sensor, the sensing microfilament absorbs the gas. The electromagnetic wave generator emits vibrational electromagnetic waves to the quartz tuning fork and the sensing microfilament, causing them to resonate upon receiving the vibrational electromagnetic waves and transmit a mechanical resonance signal to the signal processing module. The signal processing module collects the mechanical resonance signal and obtains the concentration of the gas to be measured based on the mechanical resonance signal.

[0008] The aforementioned gas concentration sensing device utilizes a sensing microfilament that undergoes varying degrees of adsorption reactions with different concentrations of the target gas, forming new compounds. This chemical reaction alters the Young's modulus (elastic modulus) and electrical conductivity of the microfilament, causing the overall resonant frequency of the quartz tuning fork and microfilament to change accordingly. By connecting the microfilament to the quartz tuning fork, the device can directly measure the sensor's resonant frequency at a given concentration, utilizing the variation in overall resonant frequency between the quartz tuning fork and microfilament with the target gas concentration. This allows for the deduction of the corresponding gas concentration, resulting in a simple and efficient detection process that avoids complex optical or chemical detection methods. Furthermore, the microfilament exhibits high sensitivity to the vibration waves from the electromagnetic wave receiver, further enhancing the detection performance.

[0009] In addition, the gas concentration sensing device described above acquires the mechanical resonance signal of the sensor and converts it into a resonant frequency electrical signal through a signal processing module. This allows the sensor's resonant frequency to be read directly from the conductivity spectrum, and the corresponding concentration of the gas to be measured can then be calculated, which helps to improve detection efficiency.

[0010] In one embodiment, the quartz tuning fork includes a first vibrating arm and a second vibrating arm, with both ends of the sensing microfilament electrically connected to the first vibrating arm and the second vibrating arm, respectively. The first vibrating arm is connected to a first pin, and the second vibrating arm is connected to a second pin. The first pin is electrically connected to the radio wave generator, and the second pin is electrically connected to the signal processing module.

[0011] In one embodiment, the sensor further includes a gas chamber having a cavity, in which the first vibrating arm, the second vibrating arm, and the sensing microfilament are placed, and the cavity is used to introduce the gas to be measured.

[0012] In one embodiment, the signal processing module includes a signal conversion amplifier and a data acquisition unit, which are electrically connected. The signal conversion amplifier amplifies the mechanical resonance signal and converts it into a vibration electrical signal, and adjusts the vibration electrical signal to output a resonance frequency electrical signal. The data acquisition unit collects and analyzes the resonance frequency electrical signal to obtain the concentration of the gas to be measured.

[0013] In one embodiment, the sensing microfilament is a palladium wire, and the gas to be measured is a hydrogen mixture.

[0014] In one embodiment, there is a gap between the first vibrating arm and the second vibrating arm, the width of the gap being in the range of 200μm-300μm, the diameter of the palladium wire being in the range of 20μm-100μm, and the length of the palladium wire being greater than the width of the gap and less than 1.5mm.

[0015] In one embodiment, the elastic modulus of the quartz tuning fork is 18kN / m-22kN / m.

[0016] In one embodiment, the quartz tuning fork is a 32.768kHz cylindrical crystal oscillator.

[0017] On the other hand, this application also provides a gas concentration detection method, which uses the gas concentration sensing device as described above, and includes the following steps:

[0018] S100. A calibration gas of known concentration is introduced into the sensor, wherein the calibration gas and the gas to be measured are of the same type.

[0019] S200. Start the radio wave generator and the signal processing module. The radio wave generator emits vibration radio waves to the quartz tuning fork and the sensing microfilament, causing the quartz tuning fork and the sensing microfilament to resonate after receiving the vibration radio waves and transmit a mechanical resonance signal to the signal processing module. The signal processing module processes the mechanical resonance signal and outputs a resonance frequency electrical signal.

[0020] S300. Adjust the concentration of the calibration gas so that the signal processing module fits the resonant frequency electrical signal at different concentrations and outputs the resonant frequency-concentration relationship calibration curve of the sensor.

[0021] S400. The gas to be measured is introduced into the sensor, so that the signal processing module outputs a target resonance frequency electrical signal, and the concentration of the gas to be measured is calculated based on the target resonance frequency electrical signal and the resonance frequency-concentration relationship calibration curve.

[0022] The aforementioned gas concentration detection method first introduces a calibration gas of known concentration into the sensor. This allows the understanding of the relationship between the sensor's resonant frequency and different concentrations, serving as a standard for detecting the concentration of the gas to be measured. Next, by introducing the gas to be measured into the sensor, the concentration of the gas can be calculated based on the resonant frequency-concentration calibration curve. Furthermore, this gas concentration detection method utilizes the characteristic that the overall resonant frequency of the quartz tuning fork and sensing microfilament of the gas concentration sensing device changes with the concentration of the gas to directly measure the sensor's resonant frequency at a corresponding concentration. This allows for the reverse deduction of the corresponding concentration value of the gas to be measured. The detection process is simple and efficient, avoiding complex optical or chemical detection processes. Moreover, the sensing microfilament exhibits high sensitivity in receiving the vibration waves of the electromagnetic wave vibrator, contributing to improved detection results.

[0023] In one embodiment, before step S100, the method further includes the step of continuously introducing the gas to be measured into the sensor for a preset duration to release the residual stress of the quartz tuning fork and the sensing microfilament. Attached Figure Description

[0024] Figure 1 is a schematic diagram of the structure of a gas concentration sensing device in one embodiment of this application.

[0025] Figure 2 shows the curve of the resonant frequency of the quartz tuning fork of the gas concentration sensing device of this application as a function of hydrogen concentration.

[0026] Figure 3, as a comparative experiment, shows the curve of the resonant frequency of a quartz tuning fork without palladium wire as a function of hydrogen concentration.

[0027] Figure 4 is a flowchart of a gas concentration detection method in one embodiment of this application.

[0028] Figure 5 shows the response curves of the gas concentration sensing device of this application to different hydrogen concentrations.

[0029] Explanation of icon numbers

[0030] 100, Sensor; 100a, Air Chamber; a1, Air Inlet; a2, Air Outlet; 101, Signal Input Terminal; 102, Signal Output Terminal; 110, Quartz Tuning Fork; 111, First Vibrating Arm; 112, Second Vibrating Arm; 113, First Pin; 114, Second Pin; 120, Sensing Microfilament; 121, Palladium Wire; 200, Radio Wave Generator; 300, Signal Processing Module; 310, Signal Conversion Amplifier; 311, Transimpedance Preamplifier; 312, Lock-in Amplifier; 320, Data Acquisition Unit. Detailed Implementation

[0031] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0032] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0033] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0034] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0035] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0036] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0037] Referring to Figure 1, Figure 1 shows a schematic diagram of the structure of a gas concentration sensing device according to an embodiment of this application. The gas concentration sensing device provided in an embodiment of this application includes a sensor 100, an electromagnetic wave generator 200, and a signal processing module 300. The electromagnetic wave generator 200 is electrically connected to the signal input terminal 101 of the sensor 100, and the signal processing module 300 is electrically connected to the signal output terminal 102 of the sensor 100. The sensor 100 includes a quartz tuning fork 110 and a sensing microfilament 120 electrically connected. When a gas to be measured is introduced into the sensor 100, the sensing microfilament 120 absorbs the gas. The electromagnetic wave generator 200 emits vibrational electromagnetic waves to the quartz tuning fork 110 and the sensing microfilament 120, causing them to resonate upon receiving the vibrational electromagnetic waves and transmit a mechanical resonance signal to the signal processing module 300. The signal processing module 300 collects the mechanical resonance signal and obtains the concentration of the gas to be measured based on the mechanical resonance signal.

[0038] In the aforementioned gas concentration sensing device, the sensing microfilament 120 can undergo adsorption reactions with different concentrations of the target gas to varying degrees, forming new compounds. This chemical reaction alters the Young's modulus (elastic modulus) and electrical conductivity of the sensing microfilament 120, causing the overall resonant frequency of the quartz tuning fork 110 and the sensing microfilament 120 to change accordingly. Furthermore, by connecting the sensing microfilament 120 to the quartz tuning fork 110, the device can directly measure the resonant frequency of the sensor 100 at a corresponding concentration by utilizing the characteristic that the overall resonant frequency of the quartz tuning fork 110 and the sensing microfilament 120 changes with the concentration of the target gas. This allows for the deduction of the corresponding concentration value of the target gas, resulting in a simple and efficient detection process that avoids complex optical or chemical detection procedures. Additionally, the sensing microfilament 120 exhibits high sensitivity to the vibration waves of the electromagnetic wave receiver, further enhancing the detection effect. It should be noted that the above-mentioned "absorbing the gas to be tested by the sensing microfilament 120" refers to the adsorption and desorption process of the gas to be tested on the sensing microfilament 120, in which gas molecules interact with the solid surface.

[0039] In addition, the gas concentration sensing device described above can acquire the mechanical resonance signal of the sensor 100 and convert it into a resonant frequency electrical signal through the signal processing module 300. This enables the direct reading of the resonant frequency of the sensor 100 from the conductivity spectrum, and then the corresponding concentration of the gas to be measured can be calculated, which helps to improve the detection efficiency.

[0040] In one embodiment, the aforementioned radio wave generator 200 can be a function generator. The function generator is used to generate a sine wave with a specific peak value, preferably 400mV, and the modulation frequency of the function generator is controlled by a computer to sweep across the overall resonant frequency of the quartz tuning fork 110 and the sensing microfilament 120, so that the quartz tuning fork 110 and the sensing microfilament 120 can resonate as a whole after receiving the corresponding vibration radio wave.

[0041] In some embodiments, the sensing microfilament 120 is a palladium wire 121, and the gas to be measured is a hydrogen mixture. Specifically, the reaction between hydrogen and palladium typically involves the adsorption and desorption of hydrogen on palladium. Palladium is a noble metal with good catalytic properties and can form hydrides with hydrogen. During adsorption, hydrogen molecules can be adsorbed by palladium, forming physical adsorption or chemisorption. Physical adsorption refers to the simple attachment of hydrogen molecules to the palladium surface, while chemisorption involves the formation of chemical bonds between hydrogen molecules and palladium atoms.

[0042] Furthermore, in this embodiment, after the palladium wire 121 undergoes a chemical reaction with hydrogen in the gas to be measured, a new compound, palladium hydride (PdH), is formed on its surface. This causes a change in the Young's modulus of the palladium wire 121, and also alters its conductivity and resistance. Since the palladium wire 121 is electrically connected to the quartz tuning fork 110, this results in a change in the ability of the quartz tuning fork 110 to receive the vibration waves of the radio wave generator 200. Therefore, by utilizing the characteristic that the reaction of the palladium wire 121 with hydrogen in the gas to be measured at different concentrations produces different Young's moduli and conductivity properties, the gas concentration sensing device of this application can be applied to the detection of different hydrogen concentrations.

[0043] Furthermore, in the embodiment where "the sensing microfilament 120 is a palladium wire 121, and the gas to be measured is a hydrogen mixture," the magnetic susceptibility of the palladium wire 121 decreases significantly after absorbing hydrogen, and becomes zero when the palladium wire 121 and hydrogen form a PdH0.62 compound. This helps increase the electromagnetic interference resistance of the gas concentration sensing device of this application, thereby helping to expand the application scenarios of the gas concentration sensing device of this application. For example, in a hydrogen production scenario, when a magnetic field needs to be applied to increase the hydrogen yield, the gas concentration sensing device of this application will not be affected by the magnetic field, thus ensuring its performance in measuring hydrogen concentration during the hydrogen production process.

[0044] In addition, this embodiment shows an example of hydrogen reacting with palladium. It is understood that other embodiments of the gas to be tested reacting with the corresponding material of the sensing microfilament 120 to achieve the detection of other gas concentrations should also fall within the scope of protection of this application, and will not be described in detail here.

[0045] Through experiments, the applicant concluded that, compared to the quartz tuning fork 110 without the palladium wire 121 attached, the present application's solution, after attaching the palladium wire 121 to the quartz tuning fork 110, increases the resonant frequency of the quartz tuning fork 110 from 32768Hz to 32986.9Hz, resulting in a frequency drift of 218.9Hz. Furthermore, when the palladium wire 121 absorbs hydrogen molecules, its Young's modulus and conductivity change. When the radio wave generator 200 electrically excites the quartz tuning fork 110 to vibrate, the changes in the Young's modulus and conductivity of the palladium wire 121 significantly improve the response of the palladium wire 121 to the vibration radio waves of the radio wave generator 200. This helps to improve the detection efficiency and detection accuracy of the gas concentration sensing device of this application.

[0046] Referring to Figure 2, Figure 2 shows the change in resonant frequency of the quartz tuning fork 110 with palladium wire 121 attached as a function of hydrogen concentration. When the hydrogen concentration increases from 0% to 100%, the resonant frequency of the quartz tuning fork 110 with palladium wire 121 attached increases from 32986.9 Hz to 33003.6 Hz, resulting in a frequency drift of 16.7 Hz.

[0047] Figure 3, as a comparative experiment, shows the resonant frequency of the quartz tuning fork 110 without palladium wire 121 as a function of hydrogen concentration. As the hydrogen concentration increases from 0% to 100%, the frequency of the quartz tuning fork 110 without palladium wire 121 changes by only 5.8 Hz, which is about one-third of the frequency change of the quartz tuning fork 110 with palladium wire 121. Furthermore, the amplitude of the vibration curve shows a significant decrease, indicating that the change in the resonant frequency of the tuning fork quartz crystal after applying palladium wire 121 originates from the change in the elastic modulus of palladium wire 121 in the hydrogen gas gradient field, as well as the change in the conductivity of palladium wire 121 after reacting with hydrogen.

[0048] This further illustrates that the gas concentration sensing device of this application is connected to a palladium wire 121. When the palladium wire 121 absorbs hydrogen molecules, its Young's modulus and conductivity change. Furthermore, when the quartz tuning fork 110 is electrically excited by the radio wave generator 200, this change in Young's modulus and conductivity greatly improves the response of the palladium wire 121 to the vibration radio waves of the radio wave generator 200. This helps to improve the detection efficiency and detection accuracy of the gas concentration sensing device of this application.

[0049] Referring again to Figure 1, in some embodiments, the quartz tuning fork 110 includes a first vibrating arm 111 and a second vibrating arm 112. The two ends of the sensing microfilament 120 are electrically connected to the first vibrating arm 111 and the second vibrating arm 112, respectively. The first vibrating arm 111 is connected to a first pin 113, and the second vibrating arm 112 is connected to a second pin 114. The first pin 113 is electrically connected to the radio wave generator 200, and the second pin 114 is electrically connected to the signal processing module 300. The structure is simple and reliable.

[0050] Specifically, electrodes are provided on both the first vibrating arm 111 and the second vibrating arm 112, and the two ends of the sensing microwire 120 are connected to the electrodes on the first vibrating arm 111 and the second vibrating arm 112, thus realizing the electrical connection between the sensing microwire 120 and the quartz tuning fork 110. The aforementioned sensing microwire 120 can be suspended between the first vibrating arm 111 and the second vibrating arm 112 by overlapping, such as by Coulomb force contact or adhesive bonding.

[0051] Furthermore, before the sensing microfilaments 120 are overlapped, they can be fixed on two three-dimensional displacement stages to straighten them, and then transferred and overlapped onto the quartz tuning fork 110 while maintaining the straight state. This helps to improve the elastic modulus of the sensing microfilaments 120 and improve the adsorption effect on the gas to be measured.

[0052] In addition, before using the sensor 100, the gas to be measured needs to be circulated into the sensor 100 to eliminate residual stress formed by the adhesion of the sensing microfilaments 120. For example, in an embodiment where the sensing microfilament 120 is a palladium wire 121 and the gas to be measured is a hydrogen mixture, if the hydrogen mixture is a mixture of hydrogen and nitrogen, then pure hydrogen and pure nitrogen need to be circulated into the sensor 100 multiple times to eliminate residual stress formed by the adhesion of the sensing microfilaments 120, which helps to improve detection accuracy.

[0053] In some embodiments, the sensor 100 further includes a gas chamber 100a, which has a cavity in which a first vibrating arm 111, a second vibrating arm 112, and a sensing microfilament 120 are placed. The cavity is used to introduce the gas to be measured, thereby placing the first vibrating arm 111, the second vibrating arm 112, and the sensing microfilament 120 in a cavity filled with the gas to be measured, thereby improving the accuracy of the detection.

[0054] Furthermore, the gas chamber 100a also includes an inlet a1 and an outlet a2. The inlet a1 and outlet a2 are used to introduce and discharge the gas to be measured, respectively. The gas to be measured can flow through the cavity of the gas chamber 100a through the inlet a1 and outlet a2. In this way, the gas to be measured can fill the cavity of the gas chamber 100a in a continuous flow state. This helps to ensure that the concentration of the gas to be measured remains unchanged and prevents the concentration of the gas to be measured from decreasing after the sensing microfilament 120 absorbs part of the gas to be measured, which would cause detection error.

[0055] In some embodiments, the signal processing module 300 includes a signal conversion amplifier 310 and a data acquisition unit 320. The signal conversion amplifier 310 and the data acquisition unit 320 are electrically connected. The signal conversion amplifier 310 amplifies the mechanical resonance signal and converts it into a vibration electrical signal, then modulates the vibration electrical signal to output a resonant frequency electrical signal, which is finally transmitted to the data acquisition unit 320. The data acquisition unit 320 collects and analyzes the resonant frequency electrical signal, and finally calculates the concentration of the gas to be tested based on the resonant frequency-concentration relationship. This converts the mechanical signal of the quartz tuning fork 110 vibration into an electrical signal output, avoiding the complex optical or chemical detection processes in traditional detection technologies, and helping to improve the detection effect and efficiency.

[0056] In some embodiments, the signal conversion amplifier 310 includes a piezoelectric transducer (not shown), a transimpedance preamplifier 311, and a lock-in amplifier 312. The piezoelectric transducer is disposed on the quartz tuning fork 110, thereby utilizing the piezoelectric effect of the quartz tuning fork 110 to convert the mechanical vibration of the quartz tuning fork 110 into an electrical signal output. The transimpedance preamplifier 311 is electrically connected to the lock-in amplifier 312.

[0057] The piezoelectric effect refers to the phenomenon where certain materials generate electric charges or electric fields on their surface or within themselves when subjected to mechanical stress (such as pressure or tension). The transimpedance preamplifier 311, also known as a charge amplifier, converts the small charge signal generated by the piezoelectric transducer into a voltage signal for further measurement and analysis. The piezoelectric transducer converts the mechanical resonance signal of the quartz tuning fork 110 into a piezoelectric signal and transmits it to the transimpedance preamplifier 311. The transimpedance preamplifier 311 amplifies the weak piezoelectrically converted electrical signal and transmits it to the lock-in amplifier 312. The lock-in amplifier 312 modulates the output signal of the transimpedance preamplifier 311 and outputs a frequency response curve, which is ultimately transmitted to the data acquisition unit 320.

[0058] In some embodiments, the data acquisition unit 320 includes a data acquisition card and a data processing center. The data acquisition card is used to receive the response curve of the lock-in amplifier 312's modulation output, and the data processing module is used to fit the response curve and, based on the relationship between the concentration of the gas to be measured and the resonant frequency of the quartz tuning fork 110 and the sensing microfilament 120, finally output the concentration of the gas to be measured.

[0059] In the embodiment where the sensing microfilament 120 is a palladium wire 121 and the gas to be measured is a hydrogen mixture, a gap exists between the first vibrating arm 111 and the second vibrating arm 112. The width of the gap ranges from 200 μm to 300 μm. The diameter of the palladium wire 121 ranges from 20 μm to 100 μm, and the length of the palladium wire 121 is greater than the width of the gap but less than 1.5 mm. This allows the dimensions of the palladium wire 121 and the vibrating arm to be set within a reasonable range, thereby helping to improve the response sensitivity of the quartz tuning fork 110 to the radio wave generator 200.

[0060] Furthermore, in the embodiment where "the sensing microfilament 120 is a palladium wire 121, and the gas to be measured is a hydrogen mixture," the elastic modulus of the quartz tuning fork 110 is 18 kN / m-22 kN / m. Specifically, the resonant frequency of the sensor 100 is jointly determined by the modulus of the quartz tuning fork 110 itself and the Young's modulus and conductivity of the palladium wire 121. Setting the elastic modulus of the quartz tuning fork 110 within a suitable range, such as the 18 kN / m-22 kN / m range in this embodiment, helps to improve the response sensitivity of the sensor 100 to the radio wave generator 200.

[0061] In some embodiments, the elastic modulus of the quartz tuning fork 110 is 18 kN / m; in other embodiments, the elastic modulus of the quartz tuning fork 110 is 22 kN / m; preferably, in some embodiments, the elastic modulus of the quartz tuning fork 110 is 20 kN / m.

[0062] In some embodiments, the quartz tuning fork 110 is a commercially available passive tuning fork-type quartz crystal oscillator with frequencies including but not limited to 20kHz, 25kHz, 30.7kHz, 32.768kHz, 40kHz, and 100kHz. Preferably, in some embodiments, the quartz tuning fork 110 is a 32.768kHz cylindrical crystal oscillator. Specifically, cylindrical crystal oscillators are one of the earliest and most widely used series of quartz crystal resonators, with 32.768kHz being the most common frequency, and are widely used in various fields. The quartz tuning fork 110 in this embodiment is designed as a 32.768kHz cylindrical crystal oscillator, which helps to improve the applicability of the gas concentration sensing device. It is understood that embodiments of the gas concentration sensing device using other models of the quartz tuning fork 110 should also fall within the protection scope of this application.

[0063] Referring to Figure 4, this application also provides a gas concentration detection method, which employs the gas concentration sensing device described above, and includes the following steps:

[0064] S100. A calibration gas of known concentration is introduced into the sensor 100. The calibration gas and the gas to be measured are of the same type.

[0065] S200, start the radio wave generator 200 and the signal processing module 300. The radio wave generator 200 emits vibration radio waves to the quartz tuning fork 110 and the sensing microfilament 120, causing the quartz tuning fork 110 and the sensing microfilament 120 to resonate after receiving the vibration radio waves, and transmit the mechanical resonance signal to the signal processing module 300. The signal processing module 300 processes the mechanical resonance signal and outputs the resonance frequency electrical signal.

[0066] S300: Adjust the concentration of the calibration gas so that the signal processing module 300 fits the resonant frequency electrical signal at different concentrations and outputs the resonant frequency-concentration relationship calibration curve of the sensor 100.

[0067] S400, the gas to be measured is introduced into the sensor 100, so that the signal processing module 300 outputs the target resonance frequency electrical signal, and the concentration of the gas to be measured is calculated based on the target resonance frequency electrical signal and the resonance frequency-concentration relationship calibration curve.

[0068] The aforementioned gas concentration detection method first introduces a calibration gas of known concentration into the sensor 100. This allows the relationship between the resonant frequency of the sensor 100 and different concentrations to be determined, which can then be used as a standard for detecting the concentration of the gas to be measured. Next, by introducing the gas to be measured into the sensor 100, the concentration of the gas to be measured can be calculated based on the resonant frequency-concentration calibration curve. Furthermore, this gas concentration detection method utilizes the characteristic that the overall resonant frequency of the quartz tuning fork 110 and the sensing microfilament 120 of the gas concentration sensing device changes with the concentration of the gas to be measured. The resonant frequency of the sensor 100 at the corresponding concentration can be directly measured, and the corresponding concentration value of the gas to be measured can be deduced. The detection process is simple and efficient, avoiding complex optical or chemical detection processes. Moreover, the sensing microfilament 120 has high response sensitivity to the vibration waves of the electromagnetic wave receiver, which helps to improve the detection effect.

[0069] Figure 5 illustrates the response curves of the gas concentration sensing device of this application to different hydrogen concentrations. When applied to the detection of hydrogen concentration, the applicant, through polynomial fitting, obtained the following functional relationship between the resonant frequency of the gas concentration sensing device and the hydrogen concentration:

[0070] y = A1 × exp(-x / t1) + y0, where y0 = 32982.7315 ± 0.68096; A1 = 3.98026 ± 0.547; t1 = -60.22241 ± 3.99075. The correlation coefficient of the fit reaches 0.99, indicating that the empirical formula has good adaptability. The above-mentioned gas concentration detection method of this application has high detection accuracy for hydrogen concentration.

[0071] In some embodiments, before step S100, the method further includes the step of continuously introducing the gas to be tested into the sensor 100 for a preset duration to release the residual stress of the quartz tuning fork 110 and the sensing microfilament 120, which helps to improve the detection accuracy.

[0072] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0073] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A gas concentration sensing device, characterized in that, The gas concentration sensing device includes a sensor, an electromagnetic wave generator, and a signal processing module. The electromagnetic wave generator is electrically connected to the signal input terminal of the sensor, and the signal processing module is electrically connected to the signal output terminal of the sensor. The sensor includes an electrically connected quartz tuning fork and a sensing microfilament. When the gas to be measured is introduced into the sensor, the sensing microfilament absorbs the gas. The electromagnetic wave generator emits vibrational electromagnetic waves to the quartz tuning fork and the sensing microfilament, causing them to resonate upon receiving the vibrational electromagnetic waves and transmit a mechanical resonance signal to the signal processing module. The signal processing module collects the mechanical resonance signal and obtains the concentration of the gas to be measured based on the mechanical resonance signal.

2. The gas concentration sensing device according to claim 1, characterized in that, The quartz tuning fork includes a first vibrating arm and a second vibrating arm. The two ends of the sensing microwire are electrically connected to the first vibrating arm and the second vibrating arm, respectively. The first vibrating arm is connected to a first pin, and the second vibrating arm is connected to a second pin. The first pin is electrically connected to the radio wave generator, and the second pin is electrically connected to the signal processing module.

3. The gas concentration sensing device according to claim 2, characterized in that, The sensor also includes a gas chamber, which has a cavity, and the first vibrating arm, the second vibrating arm and the sensing microfilament are placed in the cavity, which is used to introduce the gas to be measured.

4. The gas concentration sensing device according to claim 1, characterized in that, The signal processing module includes a signal conversion amplifier and a data acquisition unit, which are electrically connected. The signal conversion amplifier amplifies the mechanical resonance signal and converts it into a vibration electrical signal, and adjusts the vibration electrical signal to output a resonance frequency electrical signal. The data acquisition unit collects and analyzes the resonance frequency electrical signal to obtain the concentration of the gas to be measured.

5. The gas concentration sensing device according to claim 2 or 3, characterized in that, The sensing microfilament is a palladium wire, and the gas to be measured is a mixture of hydrogen and other gases.

6. The gas concentration sensing device according to claim 5, characterized in that, There is a gap between the first vibrating arm and the second vibrating arm. The width of the gap is in the range of 200μm-300μm. The diameter of the palladium wire is in the range of 20μm-100μm. The length of the palladium wire is greater than the width of the gap and less than 1.5mm.

7. The gas concentration sensing device according to claim 5, characterized in that, The elastic modulus of the quartz tuning fork is 18kN / m-22kN / m.

8. The gas concentration sensing device according to any one of claims 1-4, characterized in that, The quartz tuning fork is a 32.768kHz cylindrical crystal oscillator.

9. A method for detecting gas concentration, employing the gas concentration sensing device as described in any one of claims 1-8, characterized in that, Includes the following steps: S100. A calibration gas of known concentration is introduced into the sensor, wherein the calibration gas and the gas to be measured are of the same type. S200. Start the radio wave generator and the signal processing module. The radio wave generator emits vibration radio waves to the quartz tuning fork and the sensing microfilament, causing the quartz tuning fork and the sensing microfilament to resonate after receiving the vibration radio waves and transmit a mechanical resonance signal to the signal processing module. The signal processing module processes the mechanical resonance signal and outputs a resonance frequency electrical signal. S300. Adjust the concentration of the calibration gas so that the signal processing module fits the resonant frequency electrical signal at different concentrations and outputs the resonant frequency-concentration relationship calibration curve of the sensor. S400. The gas to be measured is introduced into the sensor, so that the signal processing module outputs a target resonance frequency electrical signal, and the concentration of the gas to be measured is calculated based on the target resonance frequency electrical signal and the resonance frequency-concentration relationship calibration curve.

10. The gas concentration detection method according to claim 9, characterized in that, Before step S100, the method further includes the step of continuously introducing the gas to be measured into the sensor for a preset duration to release the residual stress of the quartz tuning fork and the sensing microfilament.

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