Film vacuum gauge capable of performing overvoltage self-protection

Abstract

The invention relates to the technical field of pressure detection, in particular to a film vacuum gauge capable of performing overpressure self-protection. The film vacuum gauge capable of performing overpressure self-protection comprises a shell, a film vacuum gauge main body, a stop valve, a reference barometer and a circuit board, wherein the film vacuum gauge main body is arranged in the shell; the stop valve is arranged in the shell, an outlet of the stop valve is communicated with the thin film vacuum gauge body, an inlet of the stop valve is communicated with the vacuum gauge air inlet, and the vacuum gauge air inlet is communicated with external equipment. According to the thin film vacuum gauge capable of performing overpressure self-protection, the reference barometer detects the gas pressure of the inlet of the stop valve, converts the detected pressure value into an electric signal and sends the electric signal to the circuit board, and when the gas pressure value of the inlet of the stop valve is larger than the rated working range of the thin film vacuum gauge body, the circuit board controls the stop valve to be closed; and the film vacuum gauge is isolated from the outside, so that the elastic film is effectively protected from being influenced by overload pressure, and the service life of the film vacuum gauge is prolonged.

Description

Technical Field

[0001] This invention relates to the field of pressure detection technology, and in particular to a thin-film vacuum gauge capable of self-protection against overpressure. Background Technology

[0002] Thin-film vacuum gauges, as high-precision pressure measuring devices, are widely used in vacuum pressure measurement in fields such as semiconductor processing, vacuum coating, and aerospace propulsion systems. Their core principle is to measure pressure by detecting the pressure deformation of a thin-film capacitive sensing core.

[0003] Thin-film vacuum gauges, as vacuum sensors, have relatively small measurement ranges, typically 0-100 Pa or 0-1000 Pa. Within their rated pressure range, the thin-film vacuum gauge operates normally. However, when the pressure to be measured exceeds the rated range, the diaphragm will be under overstress. For example, a thin-film vacuum gauge with a rated range of 0-100 Pa will face a pressure overload of 1000 times in an atmospheric environment. Under prolonged overload conditions, this can easily lead to drift of the thin-film vacuum gauge, affecting measurement accuracy. Summary of the Invention

[0004] This invention provides a thin-film vacuum gauge with overpressure self-protection to solve the problem that the thin-film vacuum gauge will be in an overstressed state when the pressure to be measured exceeds the rated range, which affects the measurement accuracy.

[0005] This invention provides a thin-film vacuum gauge capable of overpressure self-protection, comprising: case; A thin-film vacuum gauge body, wherein the thin-film vacuum gauge body is disposed inside the housing; A shut-off valve is disposed inside the housing. The outlet of the shut-off valve is connected to the main body of the thin-film vacuum gauge, and the inlet of the shut-off valve is connected to the air inlet of the vacuum gauge. The air inlet of the vacuum gauge is connected to external equipment. A reference barometer is disposed inside the housing, and the air inlet of the reference barometer is connected to the inlet of the shut-off valve; A circuit board is disposed inside the housing and is electrically connected to the shut-off valve and the reference barometer. The reference barometer is used to detect the gas pressure at the inlet of the shut-off valve and convert the detected pressure value into an electrical signal and send it to the circuit board. When the gas pressure at the inlet of the shut-off valve is greater than the rated working range of the thin-film vacuum gauge body, the circuit board controls the shut-off valve to close.

[0006] According to the present invention, a thin-film vacuum gauge capable of overvoltage self-protection is provided, wherein the main body of the thin-film vacuum gauge comprises: Capacitor casing; An elastic diaphragm is disposed inside the capacitor housing to divide the interior of the capacitor housing into a vacuum reference cavity and a test cavity, wherein the test cavity is connected to the outlet of the shut-off valve through a capacitor gauge tube. A fixed electrode is disposed within the vacuum reference cavity and is electrically connected to the circuit board.

[0007] According to the present invention, a thin-film vacuum gauge capable of overvoltage self-protection is provided, wherein the main body of the thin-film vacuum gauge further includes: A baffle is disposed inside the cavity to be tested.

[0008] According to the present invention, a thin-film vacuum gauge capable of overpressure self-protection is provided, wherein the distance between the baffle and the elastic film is less than the maximum deformation range of the elastic film.

[0009] According to the present invention, a thin-film vacuum gauge capable of overpressure self-protection includes a shut-off valve comprising: The valve body has the shut-off valve inlet at one end and the shut-off valve outlet at the other end. A sealing valve, wherein the sealing valve is disposed inside the valve body; A drive assembly connected to the sealing valve, the drive assembly being used to drive the sealing valve to move, thereby opening or closing the shut-off valve.

[0010] According to the present invention, a thin-film vacuum gauge capable of overpressure self-protection is provided, wherein the driving assembly includes a motor, and the rotating shaft of the motor is connected to the sealing valve.

[0011] According to the present invention, a thin-film vacuum gauge capable of overpressure self-protection is provided, wherein the valve body is provided with a channel communicating with the inlet of the shut-off valve, and the air inlet of the reference barometer is communicating with the channel.

[0012] According to the present invention, a thin-film vacuum gauge capable of overpressure self-protection is provided, wherein the rated operating range of the reference barometer is greater than the rated operating range of the thin-film vacuum gauge body.

[0013] According to the present invention, a thin-film vacuum gauge capable of overpressure self-protection is provided, wherein the rated operating range of the reference barometer is 2-5 times the rated operating range of the thin-film vacuum gauge body.

[0014] According to the present invention, a thin-film vacuum gauge capable of overpressure self-protection is provided, wherein the vacuum degree of the vacuum reference chamber is not greater than 10. -2 Pa.

[0015] The thin-film vacuum gauge with overpressure self-protection provided by this invention detects the gas pressure at the inlet of the shut-off valve by a reference barometer and converts the detected pressure value into an electrical signal and sends it to the circuit board. When the gas pressure at the inlet of the shut-off valve is greater than the rated working range of the thin-film vacuum gauge body, the circuit board controls the shut-off valve to close, isolating the thin-film vacuum gauge from the outside world. This effectively protects the elastic diaphragm from the effects of overload pressure and extends the service life of the thin-film vacuum gauge. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of the thin-film vacuum gauge with overpressure self-protection provided by the present invention.

[0018] Figure label: 1. Elastic film; 2. Fixed electrode; 3. Capacitor housing; 4. Baffle; 5. Capacitor leads; 6. Vacuum reference chamber; 7. Chamber under test; 8. Circuit; 9. Shut-off valve; 10. Valve body; 11. Drive assembly; 12. Sealing valve; 13. Reference barometer; 14. Vacuum gauge inlet; 15. Capacitor gauge tube. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0020] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of 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, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0022] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through 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. "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.

[0023] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0024] Figure 1 A schematic diagram of the structure of the thin-film vacuum gauge capable of overpressure self-protection provided by the present invention is shown, as follows: Figure 1As shown, the thin-film vacuum gauge with overpressure self-protection includes a housing, a thin-film vacuum gauge body, a shut-off valve 9, a reference barometer 13, and a circuit board 8. The housing encapsulates and protects all internal components. This integrated encapsulation design provides a robust physical barrier for all internal precision components, ensuring the stability and reliability of the instrument in complex industrial environments. The thin-film vacuum gauge body and shut-off valve 9 are both located inside the housing. This compact, integrated layout not only reduces the overall size of the device but, more importantly, minimizes the gas path. The outlet of shut-off valve 9 is directly connected to the thin-film vacuum gauge body, while its inlet is connected to the vacuum gauge inlet 14, which is connected to external equipment. By controlling the opening and closing of shut-off valve 9, gas communication and isolation between the thin-film vacuum gauge body and external equipment can be achieved.

[0025] A reference barometer 13 is located inside the housing, and its inlet is connected to the inlet of the shut-off valve 9. A circuit board 8 is also located inside the housing, electrically connected to the shut-off valve 9 and the reference barometer 13. The reference barometer 13 detects the gas pressure at the inlet of the shut-off valve 9 and converts the detected pressure value into an electrical signal, which is then sent to the circuit board 8 to provide an accurate pressure reference value for overpressure protection. When the gas pressure at the inlet of the shut-off valve 9 exceeds the rated operating range of the thin-film vacuum gauge, the circuit board 8 controls the shut-off valve 9 to close, achieving overpressure self-protection and preventing the thin-film vacuum gauge from operating under overpressure conditions.

[0026] The thin-film vacuum gauge with overpressure self-protection provided by the present invention detects the gas pressure at the inlet of the shut-off valve 9 by a reference barometer 13 and converts the detected pressure value into an electrical signal and sends it to the circuit board 8. When the gas pressure at the inlet of the shut-off valve 9 is greater than the rated working range of the thin-film vacuum gauge body, the circuit board 8 controls the shut-off valve 9 to close, isolating the thin-film vacuum gauge from the outside world, which can effectively protect the elastic diaphragm 1 from the influence of overload pressure and extend the service life of the thin-film vacuum gauge.

[0027] In one embodiment of the present invention, such as Figure 1As shown, the main body of the thin-film vacuum gauge includes a capacitor housing 3, an elastic thin film 1, and a fixed electrode 2. The elastic thin film 1 is fixedly disposed inside the capacitor housing 3, dividing the interior of the capacitor housing 3 into a vacuum reference chamber 6 and a test chamber 7 for introducing the gas to be measured. This structure utilizes the vacuum reference chamber 6 to provide an extremely stable zero-pressure reference, ensuring that any deformation of the elastic thin film 1 is only related to the absolute pressure inside the test chamber 7. This eliminates the interference of ambient atmospheric pressure fluctuations on the measurement results, ensuring high accuracy and high reliability of the measurement. The test chamber 7 is connected to the outlet of the shut-off valve 9 through the capacitor gauge tube 15, providing a standardized and controllable entry channel for the gas to be measured, facilitating reliable connection of the vacuum gauge to different vacuum systems. The fixed electrode 2 is precisely disposed inside the vacuum reference chamber 6, completely isolating the fixed electrode 2 from the outside environment. This effectively prevents changes in the physicochemical properties of the electrode surface, thereby ensuring the long-term stability of the sensor's electrical performance and the persistent consistency of the measurement results. The fixed electrode 2 is electrically connected to the circuit board 8 via the capacitor lead 5. Together with the elastic film 1, which is a movable electrode, it forms a parallel plate capacitor. When the pressure changes and causes the elastic film 1 to deform, the distance between the capacitor plates changes accordingly, resulting in a change in the capacitance value. By detecting this change in capacitance value with high precision, the circuit board 8 can calculate the corresponding accurate pressure value, thus enabling precise capture of minute pressure changes.

[0028] In one embodiment of the present invention, such as Figure 1 As shown, the vacuum level of vacuum reference cavity 6 is no greater than 10. -2 The extremely high vacuum standard of Pa provides an extremely stable reference environment for the elastic diaphragm 1, which is close to absolute zero pressure. The residual pressure generated is much smaller than the lower limit of the measurement of the thin-film vacuum gauge, so it can be ignored. This ensures that any deformation of the elastic diaphragm 1 is almost entirely caused by the absolute pressure in the chamber under test 7, which fundamentally eliminates the measurement error caused by the pressure fluctuation on the reference side and greatly improves the measurement accuracy and resolution of the vacuum gauge in the low-pressure region.

[0029] In one embodiment of the present invention, such as Figure 1 As shown, the main body of the thin-film vacuum gauge also includes a baffle 4, which is disposed inside the chamber 7 to be measured. By setting the baffle 4 inside the chamber 7 to be measured in the main body of the thin-film vacuum gauge, and the distance between the baffle 4 and the elastic thin film 1 is less than the maximum deformation range of the elastic thin film 1, a mechanical protection mechanism is formed. Even before the shut-off valve 9 responds or in the event of a malfunction, the baffle 4 can physically limit the excessive deformation of the elastic thin film 1, preventing it from rupturing due to a huge pressure difference. This provides double safety protection for the vacuum gauge and improves the reliability and durability of the product.

[0030] In one embodiment of the present invention, such as Figure 1 As shown, the shut-off valve 9 includes a valve body 10, a sealing valve 12, and a drive assembly 11. One end of the valve body 10 has an inlet for the shut-off valve 9, and the other end has an outlet for the shut-off valve 9. The sealing valve 12 is located inside the valve body 10, which not only makes the overall structure more compact but also effectively protects the sealing valve 12 from direct impact or contamination from the external environment, ensuring the long-term reliability of its sealing performance. The drive assembly 11 is connected to the sealing valve 12 and is used to drive the sealing valve 12 to move precisely inside the valve body 10, switching the shut-off valve 9 between "open" and "closed" states. When it receives a command from the circuit board 8, it can quickly execute a closing action, isolating overpressured gas from the outside.

[0031] In one embodiment of the present invention, such as Figure 1 As shown, the drive assembly 11 includes a motor, the motor shaft of which is connected to the sealing valve 12. Using a motor as a power source enables the precise conversion of electrical control commands from the circuit board 8 into mechanical energy, forming the basis for automated and intelligent valve control and making rapid response possible. The motor shaft is connected to the sealing valve 12, and through a built-in transmission structure such as a lead screw and nut mechanism or a crank-connecting rod, the rotational motion of the motor is efficiently converted into the linear reciprocating motion of the sealing valve 12, thereby reliably driving the valve to open or close. This transmission method is compact, highly efficient, and stable, ensuring that the protection action can be reliably and quickly executed when an overpressure signal is received.

[0032] In one embodiment of the present invention, such as Figure 1 As shown, the valve body 10 is provided with a channel communicating with the inlet of the shut-off valve 9, and the air inlet of the reference barometer 13 is connected to the channel. By directly integrating the pressure sampling point of the reference barometer 13 onto the valve body 10, the entire device structure is made more compact, reducing external pipeline connections and potential leakage points, and improving the overall reliability and airtightness of the system.

[0033] In one embodiment of the present invention, the reference barometer 13 can be a Pirani vacuum gauge, an absolute / differential pressure piezoresistive sensor, or an atmospheric pressure sensor, etc. These sensors all have the characteristic of measuring low vacuum to one atmosphere. This wide measurement range is the key to achieving effective protection because it completely covers the entire pressure range from working vacuum to atmospheric environment. This ensures that whether the reference barometer 13 is directly exposed to the atmosphere due to misoperation or the pressure slowly rises due to process abnormalities, it can accurately capture dangerous pressure values ​​exceeding the main body's range. This provides a reliable and accurate judgment basis for triggering the shut-off valve 9 to close, avoiding the "blind spot" of the protection function. When the circuit board 8 controls the shut-off valve 9 to close, the thin-film vacuum gauge body is isolated from the outside world and cannot detect external pressure. At this time, the circuit board 8 can directly output the gas pressure value detected by the reference barometer 13 as the measured value, ensuring that even when the thin-film vacuum gauge body is protected, the entire instrument can still provide a continuous and referable pressure reading, avoiding measurement interruption. Through this intelligent switching, not only can high-precision measurements be performed within the rated working range of the thin-film vacuum gauge body, but also relatively accurate measurements can be performed outside its range using the reference barometer 13. Ultimately, a "composite range" effect is achieved, which greatly expands the effective measurement range of a single device and integrates the functions of a high-precision vacuum gauge and a low vacuum / atmospheric barometer into one, significantly increasing the applicability of the product.

[0034] In one embodiment of the present invention, the rated operating range of the reference barometer 13 is greater than the rated operating range of the thin-film vacuum gauge body. Preferably, the rated operating range of the reference barometer 13 is 2-5 times the rated operating range of the thin-film vacuum gauge body. To ensure the stable operation of the protection system itself, the rated operating range of the reference barometer 13 is set to be greater than the rated operating range of the thin-film vacuum gauge body (e.g., 2-5 times). This ensures that when the reference barometer 13 detects an "overload" pressure for the body, it remains within its normal and accurate operating range, thereby ensuring the accuracy and effectiveness of the protection action triggering.

[0035] In one embodiment of the present invention, the rated operating range of the reference barometer 13 is greater than that of the thin-film vacuum gauge body. When the reference barometer 13 detects a pressure that threatens the thin-film vacuum gauge body, it will never exceed its own rated operating range due to the pressure, thus ensuring the authenticity and reliability of its output signal and providing an accurate basis for subsequent protection actions. Preferably, the rated operating range of the reference barometer 13 is set to 2-5 times the rated operating range of the thin-film vacuum gauge body. This provides sufficient safety margin, avoiding measurement errors caused by the reference barometer 13 approaching its own range limit, and also ensures that it still has sufficient resolution and accuracy at critical protection trigger points (i.e., near the upper limit of the thin-film vacuum gauge body's range). This achieves both rapid and accurate protection action triggering, effectively preventing protection failure or false activation due to improper threshold settings or sensor performance limitations.

[0036] In a preferred embodiment of the present invention, the thin-film vacuum gauge capable of overpressure self-protection further includes a negative pressure chamber (not shown), which is disposed inside the housing and is connected to the capacitor gauge tube 15 via a connecting pipe. A solenoid valve is installed on the connecting pipe and is electrically connected to the circuit board 8. The negative pressure chamber is normally in a negative pressure state. When the circuit board 8 controls the shut-off valve 9 to close, the gas pressure inside the capacitor gauge tube 15 is still close to or slightly greater than the rated operating range of the thin-film capacitor. At this time, the circuit board 8 controls the solenoid valve to open, making the capacitor gauge tube 15 connected to the negative pressure chamber, thus aligning the internal pressures of the capacitor gauge tube 15 and the negative pressure chamber. This reduces the internal pressure of the capacitor gauge tube 15 to a certain extent, mitigating the impact of overload pressure on the elastic diaphragm 1 caused by excessively high internal pressure in the negative pressure chamber.

[0037] The thin-film vacuum gauge with overpressure self-protection also includes a negative pressure chamber located inside the housing. This chamber is connected to the capacitor gauge tube 15 via a connecting pipe equipped with a solenoid valve electrically connected to the circuit board 8. The negative pressure chamber is normally under negative pressure, effectively creating a pre-stored "vacuum buffer volume" within the device, providing a readily available, non-waiting space for rapidly reducing residual overpressure. When the circuit board 8 controls the shut-off valve 9 to close, if the residual gas pressure in the capacitor gauge tube 15 is still close to or slightly greater than the rated operating range of the thin-film capacitor, the circuit board 8 controls the solenoid valve to open, connecting the capacitor gauge tube 15 to the negative pressure chamber. This active pressure relief operation utilizes the principle of gas expansion to rapidly draw the high-pressure gas between the shut-off valve 9 and the diaphragm into the negative pressure chamber for pressure balance, thus providing secondary pressure reduction protection for the thin-film vacuum gauge body on top of the main isolation protection. This method can quickly reduce the internal pressure of the capacitor gauge tube 15, actively alleviate the risk of continuous overload caused by gas retention in the pipeline after the main shut-off valve 9 is closed, provide dual and progressive safety protection for the elastic diaphragm 1, and further improve the survivability and reliability of the vacuum gauge under extreme working conditions.

[0038] In a preferred embodiment of the present invention, the thin-film vacuum gauge capable of overpressure self-protection further includes a one-way valve located outside the housing. The one-way valve's inlet is connected to the negative pressure chamber, and its outlet is connected to the outside. When the negative pressure chamber loses negative pressure, the solenoid valve can be closed, and the one-way valve can be connected to an external negative pressure device to pump the negative pressure chamber back to a negative pressure state for convenient use next time.

[0039] The thin-film vacuum gauge with overpressure self-protection also includes a one-way valve located outside the housing. The one-way valve's inlet connects to the negative pressure chamber, while its outlet connects to the outside. This external interface design greatly improves system maintainability, and the introduction of the one-way valve ensures that gas can only be extracted from the negative pressure chamber, effectively preventing external atmosphere from flowing back into the chamber when not being pumped, thus maintaining the negative pressure state of the chamber. When the negative pressure chamber loses its negative pressure due to use, the solenoid valve can be closed first to completely isolate the chamber from the measuring pipeline, preventing unnecessary impact on the main sensor during pumping and ensuring the safety of the regeneration process. Then, the one-way valve can be connected to an external negative pressure device to pump the chamber back to a negative pressure state. This allows the negative pressure chamber, serving as a buffer volume, to be reused. This ensures that after a protection action, the device can quickly restore its secondary pressure reduction protection capability through simple external operation, fully preparing for the next possible overpressure event and thus guaranteeing the continuous effectiveness of the device's protection function.

[0040] The thin-film vacuum gauge with overpressure self-protection provided by this invention uses a reference barometer 13 installed at the inlet of the shut-off valve 9 to pre-detect the gas pressure about to enter the body of the thin-film vacuum gauge. When the circuit board 8 determines that the gas pressure value is greater than the rated working range of the body of the thin-film vacuum gauge, it will immediately control the shut-off valve 9 to close. This active control method can quickly cut off the passage between the overpressure gas and the body of the thin-film vacuum gauge, effectively isolating it from the external dangerous pressure environment, thereby protecting the core elastic membrane 1 from the impact of overload pressure and preventing permanent deformation or damage. It avoids measurement drift caused by overstress and significantly extends the overall service life and measurement accuracy of the thin-film vacuum gauge.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A thin-film vacuum gauge capable of overvoltage self-protection, characterized in that, include: case; A thin-film vacuum gauge body, wherein the thin-film vacuum gauge body is disposed inside the housing; The shut-off valve (9) is located inside the housing. The outlet of the shut-off valve (9) is connected to the main body of the thin-film vacuum gauge, and the inlet of the shut-off valve (9) is connected to the vacuum gauge air inlet (14). The vacuum gauge air inlet (14) is connected to external equipment. Reference barometer (13), the reference barometer (13) is disposed inside the housing, and the air inlet of the reference barometer (13) is connected to the inlet of the shut-off valve (9); The circuit board (8) is located inside the housing and is electrically connected to the shut-off valve (9) and the reference barometer (13). The reference barometer (13) is used to detect the gas pressure at the inlet of the shut-off valve (9) and convert the detected pressure value into an electrical signal and send it to the circuit board (8). When the gas pressure at the inlet of the shut-off valve (9) is greater than the rated working range of the thin-film vacuum gauge body, the circuit board (8) controls the shut-off valve (9) to close.

2. The thin-film vacuum gauge capable of overvoltage self-protection according to claim 1, characterized in that, The thin-film vacuum gauge body includes: Capacitor casing (3); An elastic film (1) is disposed inside the capacitor housing (3) to divide the inside of the capacitor housing (3) into a vacuum reference cavity (6) and a test cavity (7). The test cavity (7) is connected to the outlet of the shut-off valve (9) through a capacitor gauge tube (15). A fixed electrode (2) is disposed inside the vacuum reference cavity (6) and is electrically connected to the circuit board (8).

3. The thin-film vacuum gauge capable of overvoltage self-protection according to claim 2, characterized in that, The main body of the thin-film vacuum gauge also includes: Baffle (4) is disposed inside the cavity to be tested (7).

4. The thin-film vacuum gauge capable of overvoltage self-protection according to claim 3, characterized in that, The distance between the baffle (4) and the elastic film (1) is less than the maximum deformation range of the elastic film (1).

5. The thin-film vacuum gauge capable of overpressure self-protection according to any one of claims 1 to 4, characterized in that, The shut-off valve (9) includes: The valve body (10) has an inlet for the shut-off valve (9) at one end and an outlet for the shut-off valve (9) at the other end. A sealing valve (12) is disposed inside the valve body (10); A drive assembly (11) is connected to the sealing valve (12) and is used to drive the sealing valve (12) to move so that the shut-off valve (9) opens or closes.

6. The thin-film vacuum gauge capable of overvoltage self-protection according to claim 5, characterized in that, The drive assembly (11) includes a motor, the shaft of which is connected to the sealing valve (12).

7. The thin-film vacuum gauge capable of overvoltage self-protection according to claim 5, characterized in that, The valve body (10) is provided with a channel that communicates with the inlet of the shut-off valve (9), and the air inlet of the reference barometer (13) is communicated with the channel.

8. The thin-film vacuum gauge capable of overvoltage self-protection according to claim 5, characterized in that, The rated operating range of the reference barometer (13) is greater than the rated operating range of the thin-film vacuum gauge body.

9. The thin-film vacuum gauge capable of overvoltage self-protection according to claim 5, characterized in that, The rated operating range of the reference barometer (13) is 2-5 times the rated operating range of the thin-film vacuum gauge body.

10. The thin-film vacuum gauge capable of overpressure self-protection according to any one of claims 2 to 4, characterized in that, The vacuum level of the vacuum reference cavity (6) is no greater than 10. -2 Pa.

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