Optical hydrogen sensor based on magnesium-based hydrochromic film

Abstract

The utility model provides an optical hydrogen sensor based on a magnesium-based hydrochromic film, which comprises a substrate and a shading shell, and the substrate is detachably connected with the shading shell; a sensing unit, a sensing unit, a display unit, a microprocessor, a light source and a power supply are arranged on the substrate; wherein the sensing unit is isolated from the sensing unit, the sensing unit is not in contact with hydrogen, and the sensing unit does not need to be heated or powered. According to the hydrogen sensor disclosed by the utility model, the hydrogen concentration is monitored by utilizing the hydrogen-induced discoloration phenomenon of the sensing unit, and the problems faced by the current hydrogen sensor are solved by utilizing the intrinsic characteristics of high responsiveness, high selectivity, high safety and high durability of the magnesium-based hydrogen-induced discoloration film. The hydrogen sensor is low in cost, low in power consumption, low in operation difficulty and low in environment requirement, and has an important application prospect in the field of hydrogen sensing.

Description

Technical Field

[0001] The utility model relates to the technical field of gas sensors, in particular to an optical hydrogen sensor. Background Art

[0002] Hydrogen is an ideal energy source for achieving the dual carbon goals, offering advantages such as high calorific value, zero carbon emissions, and high energy conversion efficiency. However, hydrogen is colorless and odorless, making it difficult to detect. It is also flammable and explosive, with an explosive limit in air of 4.0% to 75.6%. Its ignition energy is low, requiring only 0.019 mJ of heat to initiate combustion. Furthermore, its small size makes it susceptible to leakage, raising significant safety concerns for hydrogen. Therefore, a sensitive, accurate, safe, and reliable hydrogen sensor is crucial for the entire hydrogen energy industry chain.

[0003] Currently, the most mature hydrogen sensors are primarily catalytic combustion sensors. These sensors are susceptible to electromagnetic interference, require heating and an oxygen environment, and respond to a variety of combustible gases, making them difficult to adapt to the practical needs of complex industrial environments. Optical hydrogen sensors, on the other hand, detect light signals independently of wire transmission, effectively separating the reader from the sensing point, eliminating safety hazards. Furthermore, optical sensors based on the hydrogen-induced color principle offer inherently high selectivity and sensitivity, offering broader application prospects.

[0004] Hydrochromism refers specifically to the transition of certain metals, particularly magnesium, from a metallic to a semiconductor state upon hydrogenation, resulting in changes in their macroscopic optical properties (transmittance / reflectance). Magnesium has a high theoretical hydrogen storage capacity, is environmentally friendly, and is abundant. This optical property transition can be achieved at room temperature under palladium catalysis. Magnesium-based hydrochromic films exhibit high responsiveness, selectivity, safety, and durability.

[0005] Currently, optical hydrogen sensors rely on complex optical systems for hydrogen detection. These devices are bulky and mostly stationary, making them difficult to flexibly detect hydrogen leak sources. Furthermore, they are costly, energy-intensive, and complex to operate, hindering long-term detection and prompt response to emergencies. They cannot meet the demands of multi-site, large-scale deployment in scenarios such as hydrogen vehicles and hydrogen refueling stations.

[0006] Therefore, it is necessary to utilize the advantages of the intrinsic high selectivity and high sensitivity of magnesium-based hydrogen chromic films to develop a low-cost, low-power portable optical hydrogen sensor suitable for different environmental requirements. Utility Model Content

[0007] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide an optical hydrogen sensor to solve the problems of low selectivity and sensitivity of catalytic combustion hydrogen sensors under existing technical conditions and the complexity and high cost of existing optical hydrogen sensor equipment.

[0008] The purpose of this utility model is achieved through the following technical solutions:

[0009] In a first aspect, the utility model provides an optical hydrogen sensor, comprising a substrate and a light-shielding housing, wherein the substrate and the light-shielding housing are detachably connected; a sensitive unit, a sensing unit, a display unit, a microprocessor, a light source, and a power supply are provided on the substrate;

[0010] The sensitive unit is arranged between the light source and the sensing unit, and the sensing unit is used to collect the light signal passing through the sensitive unit;

[0011] One end of the microprocessor is electrically connected to the sensor unit, and the other end is electrically connected to the display unit; the microprocessor is used to convert the optical signal input by the sensor unit into a digital signal and display it on the display unit;

[0012] The power supply is electrically connected to the light source, the display unit, and the microprocessor respectively;

[0013] A display window and an air inlet are provided above the light-shielding housing, and the display window is located above the display unit;

[0014] A partition is further provided between the sensitive unit and the sensing unit, and the partition is provided in parallel with the sensitive unit;

[0015] The sensitive unit is connected to the substrate and the light-shielding shell to form a first closed cavity, and the power supply and light source are located in the first closed cavity; the partition is connected to the substrate and the light-shielding shell to form a second closed cavity, and the sensing unit, display unit and microprocessor are located in the first closed cavity; a gas test chamber is formed between the sensitive unit and the partition, and the gas test chamber is connected to the air inlet, so that the gas from the external environment can enter the gas test chamber.

[0016] As a preferred solution, the sensitive unit is a magnesium-based hydrogen-induced chromic film.

[0017] As a preferred embodiment, the magnesium-based hydrogen-induced chromic film includes an FC protective layer, a Pd catalyst layer, a Mg-X hydrogen-sensitive layer, and a base layer arranged in sequence;

[0018] As a preferred embodiment, in the Mg-X hydrogen-sensitive layer, X is at least one of a rare earth, a transition metal or a transition metal oxide; further preferably, X is at least one of scandium, yttrium, gadolinium, titanium, nickel, molybdenum, niobium, ruthenium, zirconium, lanthanum or their oxides; most preferably, X is scandium (Sc).

[0019] As a preferred solution, the base layer is selected from any one of a quartz glass layer, an optical fiber layer, a conductive glass layer, an organic glass layer, and a flexible glass layer.

[0020] As a preferred solution, the thickness of the FC protective layer is 30 to 150 nm, the thickness of the Pd catalytic layer is 3 to 7 nm, and the thickness of the Mg-X hydrogen sensitive layer is 10 to 80 nm.

[0021] As a preferred solution, one end of the base layer of the magnesium-based hydrogenochromic film is close to the light source, and one end of the FC protective layer is far away from the light source.

[0022] As a preferred embodiment, the sensing element is a magnesium-based hydrochromic film that has undergone a hydrogen cycle stabilization treatment. This treatment involves subjecting the magnesium-based hydrochromic film to multiple cycles of hydrogen absorption and desorption at the same hydrogen concentration until the transmittance of the film stabilizes. Using a magnesium-based hydrochromic film that has undergone hydrogen cycle stabilization can further improve the accuracy of detection results.

[0023] As a preferred solution, the light source is a monochromatic LED lamp, more preferably a 520nm monochromatic LED lamp.

[0024] As a preferred solution, the connection line between the light source and the sensing unit (ie, the light path) is perpendicular to the sensing unit.

[0025] As a preferred solution, the sensing unit is a photoresistor or a photodetector.

[0026] As a preferred solution, the distance between the light source and the sensitive unit is 5 to 20 mm, and the distance between the sensitive unit and the sensing unit is 5 to 10 mm.

[0027] As a preferred solution, the partition is a transparent partition.

[0028] As a preferred solution, different types of microprocessors are selected based on actual working conditions such as detection standards, component layout, etc. Since the selected microprocessors are universal parts, they have strong compatibility, are easy to repair, update and expand functions, and are low in cost.

[0029] As a preferred solution, the substrate is a circuit board.

[0030] As a preferred solution, a switch is provided at the bottom of the substrate for turning the optical hydrogen sensor on and off.

[0031] As a preferred solution, interfaces are further provided at both ends of the substrate for connecting to external devices.

[0032] The present invention provides a method for measuring hydrogen concentration based on the aforementioned optical hydrogen sensor, comprising the following steps:

[0033] S1. Calibration of the relationship between hydrogen concentration, light transmittance, and optical signal simulation value: Place the optical hydrogen sensor in a confined space, introduce hydrogen with different concentration gradients, measure the optical signal simulation value and transmittance of the sensitive unit at different hydrogen concentrations, and then obtain a fitting curve of the logarithm of hydrogen concentration (lgH%), the optical signal simulation value, and the transmittance;

[0034] S2. Place the calibrated optical hydrogen sensor into the space to be measured and turn on the switch to measure the hydrogen concentration in the space to be measured.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. The optical hydrogen sensor designed with a magnesium-based composite film as the sensitive unit of this utility model has low cost, small size and is easy to carry; and the sensitive unit can be replaced independently, further reducing maintenance costs.

[0037] 2. The optical hydrogen sensor of this utility model has a sealed design formed by the sensitive unit and the partition, so that each charged module does not come into direct contact with hydrogen; and the sensitive unit does not require heating or power supply, there is no risk of ignition, and it is safe and reliable.

[0038] 3. Through the rational selection and layout of the light source, sensitive unit and sensing unit, the optical hydrogen sensor prepared in this invention has the characteristics of high precision, sensitive response and resistance to interference from miscellaneous gases.

[0039] 4. The optical hydrogen sensor of this utility model can change the transmittance or reflectance measurement mode according to actual needs. It is convenient and fast, easy to operate, and suitable for a variety of occasions. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Other features, objects and advantages of the present invention will become more apparent from the detailed description of the non-limiting embodiments with reference to the following drawings:

[0041] Figure 1 This is a diagram showing the structure and test principle of the sensitive unit used in the optical hydrogen sensor of the present invention;

[0042] Figure 2 This is a schematic diagram of the transmittance curve of the hydrogen absorption process of the sensitive unit used in the present invention;

[0043] Figure 3 This is a diagram showing the internal structure of the optical hydrogen sensor in an embodiment of the present utility model;

[0044] Figure 4 This is a front view of the optical hydrogen sensor in an embodiment of the present utility model;

[0045] Figure 5A fitting curve of the logarithm of hydrogen concentration lgH% and transmittance T% for hydrogen concentration calibration of the optical hydrogen sensor of the present invention;

[0046] Figure 6 for Figure 5 A fitting curve of the logarithm of hydrogen concentration lgH% and the light signal simulation value A for hydrogen concentration calibration of the optical hydrogen sensor of the present invention;

[0047] Corresponding names of the figure marks: 1-substrate; 2-light-shielding shell; 3-power supply; 4-light source; 5-sensitive unit; 6-sensing unit; 7-microprocessor; 8-display unit; 9-partition; 10-interface; 11-display window; 12-air inlet. DETAILED DESCRIPTION

[0048] Unless otherwise defined, the technical or scientific terms used in this specification and claims shall have the common meanings understood by persons having ordinary skills in the technical field to which the utility model belongs.

[0049] All values ​​listed in this article from the lowest value to the highest value refer to all values ​​obtained by incrementing one unit between the lowest value and the highest value when the difference between the lowest value and the highest value is more than two units.

[0050] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0051] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified with "first," "second," etc., may explicitly or implicitly include one or more of such features. In the description of a utility model, unless otherwise specified, "plurality" means two or more.

[0052] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0053] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art further understand the present invention, but are not intended to limit the present invention in any way. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the scope of the present invention. These modifications and improvements are all within the scope of protection of the present invention.

[0054] Example

[0055] This embodiment relates to an optical hydrogen sensor, such as Figure 3-Figure 4 The optical hydrogen sensor comprises a substrate 1 and a light-shielding housing 2, which are detachably connected. Specifically, the two are connected and detached by providing a U-shaped groove at the bottom of the light-shielding housing 2 and a protrusion on the substrate 1 that engages with the groove. This design allows for replacement of internal structural units, such as the sensor unit 5, light source 4 and power supply 3, and the chip in the microprocessor 7.

[0056] The substrate 1 is a circuit board, on which a light source 3, a power supply 4, a sensitive unit 5, a sensor unit 6, a microprocessor 7, and a display unit 8 are arranged.

[0057] Among them, the sensitive unit 5 is a magnesium-based hydrogen-induced chromic film, which can produce changes in optical properties (transmittance, reflectivity, etc.) according to changes in the hydrogen concentration in the environment, causing changes in the light signal. The magnesium-based hydrogen-induced chromic film includes an FC protective layer, a Pd catalytic layer, a Mg-X hydrogen-sensitive layer, and a base layer arranged in sequence; in the Mg-X hydrogen-sensitive layer, X is scandium; the base layer is selected from any one of a quartz glass layer, an optical fiber layer, a conductive glass layer, an organic glass layer, and a flexible glass layer; the thickness of the FC protective layer is 30 to 150 nm, the thickness of the Pd catalytic layer is 3 to 7 nm, and the thickness of the Mg-X hydrogen-sensitive layer is 10 to 80 nm. During specific implementation, the transmittance / reflectivity can be selected as the detection signal according to the needs of the actual environment, and the corresponding Mg-X hydrogen-sensitive layer material can be selected.

[0058] In one embodiment, the magnesium-based hydrochromic film can be prepared by magnetron sputtering or co-sputtering. For example, when preparing a magnesium-based hydrochromic film where X in the Mg-X hydrogen-sensitive layer is scandium, reference can be made to the preparation method for a fluorocarbon / palladium / magnesium-scandium hydrochromic film disclosed in CN113215544A. The entire process is controlled by a pre-set program, is simple to operate, exhibits good stability, produces uniform film layers, and is highly reproducible, facilitating mass production.

[0059] In a specific embodiment, the magnesium-based hydrogen-induced chromic film used is a CF / Pd / Mg-Sc film (including an FC protective layer, a Pd catalyst layer, a Mg-Sc hydrogen-sensitive layer, and quartz glass arranged in sequence), which can be prepared by the following method:

[0060] (1) Soak the quartz glass (as a substrate) in the prepared cleaning solution for 15 minutes and then rinse the quartz glass with deionized water for 1 minute; the cleaning solution is a mixed solution of concentrated sulfuric acid and hydrogen peroxide in a ratio of 3:1; place the cleaned quartz glass in the magnetron sputtering reaction chamber, and start the vacuum system to evacuate until the background vacuum degree is 3×10 -4 Pa.

[0061] (2) Heat the quartz glass to a temperature of 20-25°C, introduce working gas A (argon), and maintain a pressure of 0.4-0.6 Pa. After the pressure stabilizes, turn on the power of the palladium, magnesium, and scandium targets, close the baffles in front of each target, and pre-sputter and clean the targets for 25 minutes. Then set the co-sputtering process program, with the sputtering power of the magnesium and scandium targets at 80W and 100W, respectively, and the co-sputtering time at 200 seconds. Start depositing a magnesium-scandium film with a film thickness of 40nm.

[0062] (3) After the deposition is completed, the sputtering process program of the palladium catalyst layer is loaded while the vacuum is maintained at 0.5 Pa, and the sputtering power of the palladium target is adjusted to 40 W, the sputtering time is 14 s, and the film thickness is 5 nm. After the palladium film growth is completed, the power supply of all target materials is turned off, and the sample is continued to be purged with working gas A for 1 min, and then the sample is taken out to obtain a thin film with a composition of Pd / Mg-Sc.

[0063] (4) Place the Pd / Mg-Sc film in a reactive ion vapor deposition machine and set the process parameters of the fluorocarbon film to be 5 Pa of working gas pressure, 40 sccm of gas B flow, 600 W of gas excitation power, and 15.6 s of deposition time. Introduce working gas B (C4F8), load the process program, and deposit a fluorocarbon film with a film thickness of 30 nm. After completion, remove the sample and obtain a film with the composition of CF / Pd / Mg-Sc. The structure and detection principle are shown in the figure. Figure 1 shown.

[0064] (5) The transmittance curve of the hydrogen absorption process of the CF / Pd / Mg-Sc film obtained by the test is shown in the figure below. Figure 2 As shown by Figure 2 It can be seen that the hydrogen absorption reaction time t of CF / Pd / Mg-Sc film 90 About 8 seconds.

[0065] In one variation, to further improve the accuracy, the CF / Pd / Mg-Sc film obtained in the aforementioned step (5) is subjected to a hydrogen cycle stabilization treatment. Specifically, the CF / Pd / Mg-Sc film is subjected to multiple cycles of hydrogen absorption and desorption tests at the same hydrogen concentration until the transmittance of the CF / Pd / Mg-Sc film tends to be stable.

[0066] The light source 4 is used to provide the stable optical signal required for testing. Specifically, a monochromatic LED with a wavelength corresponding to the maximum response range can be selected based on the material of the Mg-X hydrogen-sensitive layer in the sensing unit 5. A 520nm monochromatic LED is further preferred, as it offers advantages such as stable wavelength, low energy consumption, and minimal heat generation, making it suitable for long-term, stable detection of hydrogen concentration. In one embodiment, the light source employed is a 520nm LED.

[0067] The sensing unit 6 is used to detect the light signal after passing through the sensitive unit 5. Specifically, a photoresistor or a photodetector with corresponding parameters can be selected as the sensing unit 6 according to the different materials of the Mg-X hydrogen sensitive layer in the sensitive unit 5.

[0068] Furthermore, the sensitive unit 5 is disposed between the light source 4 and the sensor unit 6 to collect light signals passing through the sensitive unit 5. A partition 9 is also disposed between the sensitive unit 5 and the sensor unit 6. The partition 9 is transparent and does not affect the transmission of light signals. The connecting line between the light source 4 and the sensor unit 6 is perpendicular to the sensitive unit 5, and the transparent partition is disposed parallel to the sensitive unit 5.

[0069] In a specific embodiment, the distance between the light source 4 and the sensitive unit 5 is 5 to 20 mm, and the distance between the sensitive unit 5 and the sensing unit 6 is 5 to 10 mm. This layout can ensure the stability, accuracy and sensitivity of signal transmission.

[0070] One end of the microprocessor 7 is electrically connected to the sensor unit 6, and the other end is electrically connected to the display unit 8. The microprocessor 7 is used to convert the optical signal input by the sensor unit 6 into a digital signal and display it on the display unit 8. Different models of microprocessors 7 can be selected according to actual working conditions such as detection standards and component layout, and this invention does not impose any particular limitation.

[0071] The display unit 8 can display the hydrogen concentration of the test environment according to the output result of the microprocessor 7 .

[0072] The power supply 3 is electrically connected to the light source 4, the sensor unit 6, the microprocessor 7, and the display unit 8, and is used to supply power to each component, and can be adjusted according to actual use conditions. In a specific embodiment, the power supply 3 is a DC power supply.

[0073] A display window 11 and an air inlet 12 are provided above the light-shielding housing 2. The display window 11 is located above the display unit 8 and is very close to the display screen of the display unit 8. The size of the display window 11 is consistent with the size of the display screen of the display unit 8. The display window 11 is made of a transparent material. The data displayed on the display screen can be read through the display window 11 without interfering with the external ambient light source inside the hydrogen sensor.

[0074] In a specific embodiment, the sensitive unit 5 is connected to the substrate 1 and the light-shielding shell 2 to form a first closed cavity, and the power supply 3 and the light source 4 are located in the first closed cavity; the partition 9 is connected to the substrate 1 and the light-shielding shell 2 to form a second closed cavity, and the sensing unit 6, the display unit 8 and the microprocessor 7 are located in the first closed cavity; a gas test chamber is formed between the sensitive unit 5 and the partition 9, and the gas test chamber is connected to the air inlet 12, so that the gas from the external environment can enter the gas test chamber, thereby realizing the test of the hydrogen concentration in the gas in the external environment.

[0075] In a specific embodiment, the light shielding housing 2 is a black light shielding housing for background light elimination and dust interference. By covering the light source 4 and the sensor unit 6, interference from the external ambient light source and various internal reflected lights is eliminated, thereby improving detection accuracy.

[0076] In a specific embodiment, a switch is further provided at the bottom of the substrate 1 for turning the optical hydrogen sensor on and off.

[0077] In a variation, at least one interface 10 is further provided at both ends of the substrate 1 for connecting to an external device, and the type of the interface 10 is not particularly limited. In a specific embodiment, a first interface and a second interface are provided at both ends of the substrate 1, respectively.

[0078] In a variation, an alarm device may be provided on the substrate to respond and sound an alarm when the hydrogen concentration detection value reaches a threshold.

[0079] The specific steps of the hydrogen concentration test method using the aforementioned optical hydrogen sensor are as follows:

[0080] Calibration of hydrogen concentration: Place the optical hydrogen sensor in a confined space, turn on the switch, and introduce 0.1% volume fraction hydrogen. The measured light signal analog value output by the display unit of the optical hydrogen sensor is 1094, and the transmittance of the sensitive unit is 17.9%. Gradually increase the hydrogen concentration to 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, and 4%, and measure the corresponding light signal analog value and transmittance. The fitting curve of the logarithm of hydrogen concentration lgH% and transmittance T% is obtained as shown below: Figure 5 As shown, the fitting curve of the logarithm of hydrogen concentration lgH% and the light signal simulation value A is as follows Figure 6 As shown, the hydrogen concentration is calibrated;

[0081] Detection: Place the optical hydrogen sensor calibrated with hydrogen concentration into the test environment, turn on the switch, and the hydrogen concentration of the test environment can be measured. The minimum detection limit is less than 0.1%.

[0082] In a variation, in the hydrogen concentration testing method, in the hydrogen concentration calibration step, the hydrogen concentration can be calibrated by measuring the reflectivity of each hydrogen concentration instead of the transmittance, and obtaining a fitting curve of the logarithm of the hydrogen concentration (lgH%) and the reflectivity.

[0083] This new device utilizes the hydrogen-induced color change phenomenon of a sensitive element to monitor hydrogen concentration. Leveraging the inherent high responsiveness, selectivity, safety, and durability of magnesium-based hydrogen-induced color film, it overcomes the challenges faced by current hydrogen sensors. Furthermore, this device offers low cost, low power consumption, easy operation, and minimal environmental requirements, making it a promising candidate for application in the field of hydrogen sensing.

[0084] The above description of the embodiments is intended to facilitate understanding and use of the utility model by those skilled in the art. Those skilled in the art will readily be able to make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the utility model is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of this utility model without departing from the scope of this utility model should be within the scope of protection of this utility model.

Claims

1. An optical hydrogen sensor, characterized in that: It includes a base plate and a light shielding shell, and the base plate and the light shielding shell are detachably connected; the base plate is provided with a sensitive unit, a sensor unit, a display unit, a microprocessor, a light source, and a power supply; The sensitive unit is arranged between the light source and the sensing unit, and the sensing unit is used to collect the light signal passing through the sensitive unit; One end of the microprocessor is electrically connected to the sensor unit, and the other end is electrically connected to the display unit; the microprocessor is used to convert the optical signal input by the sensor unit into a digital signal and display it on the display unit; The power supply is electrically connected to the light source, the display unit, and the microprocessor respectively; A display window and an air inlet are provided above the light-shielding housing, and the display window is located above the display unit; A partition is further provided between the sensitive unit and the sensing unit, and the partition is provided in parallel with the sensitive unit; The sensitive unit is connected to the substrate and the light-shielding shell to form a first closed cavity, and the power supply and light source are located in the first closed cavity; the partition is connected to the substrate and the light-shielding shell to form a second closed cavity, and the sensing unit, display unit and microprocessor are located in the first closed cavity; a gas test chamber is formed between the sensitive unit and the partition, and the gas test chamber is connected to the air inlet, so that the gas from the external environment can enter the gas test chamber.

2. The optical hydrogen sensor according to claim 1, characterized in that The sensitive unit is a magnesium-based hydrogen-induced chromic film.

3. The optical hydrogen sensor according to claim 2, characterized in that The magnesium-based hydrogen-induced chromic film comprises an FC protective layer, a Pd catalytic layer, a Mg-X hydrogen-sensitive layer, and a base layer which are arranged in sequence.

4. The optical hydrogen sensor according to claim 3, characterized in that in, In the Mg-X hydrogen-sensitive layer, X is at least one of rare earth, transition metal or transition metal oxide; The substrate layer is selected from any one of a quartz glass layer, an optical fiber layer, a conductive glass layer, an organic glass layer, and a flexible glass layer; The thickness of the FC protective layer is 30-150 nm, the thickness of the Pd catalytic layer is 3-7 nm, and the thickness of the Mg-X hydrogen sensitive layer is 10-80 nm.

5. The optical hydrogen sensor according to claim 3 or 4, characterized in that: One end of the base layer of the magnesium-based hydrogen-chromic film is close to the light source, and one end of the FC protective layer is far away from the light source.

6. The optical hydrogen sensor according to claim 3 or 4, characterized in that: The sensitive unit is a magnesium-based hydrogen-induced chromic film that has been subjected to hydrogen cycle stabilization treatment.

7. The optical hydrogen sensor according to claim 1, wherein: The light source is a monochromatic LED lamp.

8. The optical hydrogen sensor according to claim 1, wherein: The connecting line between the light source and the sensing unit is perpendicular to the sensitive unit; The distance between the light source and the sensitive unit is 5 to 20 mm, and the distance between the sensitive unit and the sensing unit is 5 to 10 mm.

9. The optical hydrogen sensor according to claim 1, wherein: The partition is a transparent partition.

10. The optical hydrogen sensor according to claim 1, wherein: A switch is provided at the bottom of the substrate for turning the optical hydrogen sensor on and off; At least one interface is also provided at both ends of the substrate for connecting to external equipment.

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