CN114486062B - Capacitance film vacuum gauge for eliminating film stress - Google Patents

Abstract

The invention belongs to the technical field of vacuum gauges, and discloses a capacitance film vacuum gauge for eliminating film stress, which comprises a shell, a pressure sensing film, a fixed electrode and a first heating element, wherein the first heating element is arranged on the shell; the shell is provided with an accommodating cavity, the pressure sensing film is arranged in the accommodating cavity, and the accommodating cavity is divided into a first cavity and a second cavity by the pressure sensing film; the fixed electrode is arranged in the first cavity and is parallel to the pressure sensing film, and the fixed electrode and the pressure sensing film form a parallel plate capacitor sensing assembly; the first heating member is disposed in the second chamber and faces the air inlet of the housing. This application is through the design that sets up first heating member in the second intracavity for first heating member can heat the gas that awaits measuring that gets into the second intracavity, makes the temperature that gets into the gas that awaits measuring in the second intracavity keep unanimous with the temperature in the second intracavity, reduces the temperature variation in the second chamber, thereby reduces the influence of temperature variation to the stress of pressure sensing film, and then improves the measurement accuracy of capacitance film vacuum gauge.

Description

Capacitance film vacuum gauge for eliminating film stress

Technical Field

The invention belongs to the technical field of vacuum gauges, and particularly relates to a capacitance film vacuum gauge for eliminating film stress.

Background

The capacitance film vacuum gauge is a vacuum gauge for full-pressure measurement, has the characteristics of high sensitivity, high precision, miniaturization, high stability, no relation between direct measurement and gas components and the like, and is widely applied to the fields of vacuum coating, new materials, aerospace, aviation and the like.

At present, the parallel plate capacitor sensing assembly capacitance value that current capacitance film vacuum gauge's pressure sensing diaphragm and fixed electrode formed is very little, for the picofarad level for the capacitance change that pressure variation that awaits measuring arouses is also very little, and, during the measurement, the gaseous temperature variation that arouses in the measurement cavity easily that awaits measuring, the temperature variation of measuring the intracavity can cause the influence to the stress of pressure sensing film, thereby influences the measurement accuracy of capacitance film vacuum gauge.

Accordingly, the prior art is in need of improvement and development.

Disclosure of Invention

An object of this application is to provide an eliminate electric capacity film vacuum gauge of film stress can heat the gas that awaits measuring that gets into the second intracavity for the temperature that gets into the gas that awaits measuring in the second intracavity keeps unanimous with the temperature in the second intracavity, avoids temperature variation to cause the influence to the diaphragm stress, thereby influences electric capacity film vacuum gauge's measurement accuracy.

The application provides a capacitance film vacuum gauge for eliminating film stress, which comprises a shell, a pressure sensing film, a fixed electrode and a first heating element, wherein the first heating element is arranged on the shell; the shell is provided with an accommodating cavity, the pressure sensing film is arranged in the accommodating cavity, and the accommodating cavity is divided into a first cavity and a second cavity by the pressure sensing film; the fixed electrode is arranged in the first cavity and is parallel to the pressure sensing film, and the fixed electrode and the pressure sensing film form a parallel plate capacitor sensing assembly; the first heating member is disposed in the second cavity and faces the air inlet of the housing.

The application provides an eliminate capacitance film vacuum gauge of film stress is through the design of setting up first heating member in the second intracavity for first heating member heats the gas that awaits measuring that gets into the second intracavity by the air inlet of casing, thereby makes the temperature of the gas that awaits measuring keep unanimous with the temperature in the second intracavity, avoids the gas that awaits measuring to arouse the temperature variation in the second intracavity, causes the influence to the stress of pressure sensing film, thereby influences the measurement accuracy of capacitance film vacuum gauge.

Further, the first heating member is conical, the tip of the conical first heating member is close to the air inlet of the housing, and the tail end of the conical first heating member is close to the pressure-sensitive film.

This application is through being the toper with first heating member design for the gaseous one that awaits measuring that gets into the second chamber by the air inlet of casing is promptly heated by the pointed end of first heating member in getting into the second chamber, along with the gaseous continuous upward flow that awaits measuring, first heating member heats the gaseous one that awaits measuring that gets into the second chamber all the time, thereby make the gaseous temperature that awaits measuring that gets into the second chamber keep unanimous with the temperature in the second chamber, avoid the gaseous temperature variation that arouses in the second chamber that awaits measuring, the stress to the pressure sensing film causes the influence.

Furthermore, the first heating member is disc-shaped, and the disc-shaped first heating member is close to the air inlet of the shell or the pressure sensing film.

This application is through being the disc with first heating member design, and set up its position at the air inlet that is close to the casing, make the gas that awaits measuring get into the second intracavity back, directly by first heating member heating to keep unanimous with the temperature in the second intracavity, or set up its position near pressure sensing film, gas that awaits measuring gets into the second intracavity to the in-process that pressure sensing film flows by first heating member heating to keep unanimous with the temperature in the second intracavity, thereby avoid the gas that awaits measuring to arouse the temperature variation in the second intracavity.

Furthermore, the number of the first heating members is multiple, the first heating members are all disc-shaped, and the first heating members are arranged in the second cavity at intervals from bottom to top.

Further, the size of the first heating member positioned below in the two adjacent first heating members is smaller than that of the first heating member positioned above.

Further, the intervals between the adjacent two first heating members are equal.

Furthermore, a temperature control switch is arranged on the first heating member.

Furthermore, the outer side wall of the shell is wrapped with a second heating element.

Furthermore, a support frame is arranged in the second cavity, and the first heating element is arranged on the support frame.

Furthermore, a baffle is arranged at the air inlet of the shell.

Therefore, the capacitance film vacuum gauge for eliminating the film stress has the advantages that through the design that the first heating element is arranged in the second cavity, the first heating element heats the gas to be measured entering the second cavity from the air inlet of the shell, so that the temperature of the gas to be measured entering the second cavity is consistent with the temperature in the second cavity, the temperature change in the second cavity caused by the gas to be measured is avoided, the stress of the pressure-sensitive film is influenced, and the measurement precision of the capacitance film vacuum gauge is influenced.

Additional features and advantages of the present application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the present application. The objectives and other advantages of the application may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

Fig. 1 is a schematic structural diagram of a capacitance thin film vacuum gauge for relieving film stress according to an embodiment of the present disclosure.

Fig. 2 is a schematic structural diagram of a first heating element according to an embodiment of the present application.

Fig. 3 is a schematic structural diagram of a capacitance film vacuum gauge for relieving film stress according to the second embodiment of the present application.

Fig. 4 is a schematic structural diagram of a first heating element according to a second embodiment of the present application.

Fig. 5 is a schematic structural diagram of a capacitance film vacuum gauge for relieving film stress according to a third embodiment of the present application.

Fig. 6 is a schematic structural diagram of a first heating element according to a third embodiment of the present application.

Fig. 7 is a schematic structural diagram of another capacitance film vacuum gauge for relieving film stress according to a third embodiment of the present application.

Fig. 8 is a schematic structural view of another first heating element according to a third embodiment of the present application.

Description of the reference symbols: 10. a housing; 101. a first chamber; 102. a second chamber; 11. a pressure-sensitive film; 12. a fixed electrode; 13. a first heating member; 14. a second heating member; 15. a support frame; 16. a baffle plate; 17. a connecting pipe; 18. an air exhaust pipe; 19. a getter.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be mechanically, electrically or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or may be connected through the use of two elements or the interaction of two elements. The specific meanings of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The following disclosure provides many different embodiments or examples for implementing different features of the invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. Moreover, the present invention may repeat reference numerals and/or reference letters in the various examples, which have been repeated for purposes of simplicity and clarity and do not in themselves dictate a relationship between the various embodiments and/or configurations discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

Example one

As shown in fig. 1 and 2, the capacitance film vacuum gauge for relieving film stress of the present invention includes a housing 10, a pressure-sensitive film 11, a fixed electrode 12 and a first heating member 13. The housing 10 has a receiving cavity in which the pressure sensing film 11 is disposed, and the receiving cavity is divided into a first cavity 101 and a second cavity 102 by the pressure sensing film 11. The fixed electrode 12 is disposed in the first chamber 101 and parallel to the pressure-sensitive film 11, and the fixed electrode 12 and the pressure-sensitive film 11 constitute a parallel plate capacitor sensor assembly. The first heating member 13 is disposed in the second chamber 102, and the first heating member 13 faces the air inlet of the housing 10. Specifically, the first heating member 13 facing the inlet of the housing 10 means that the first heating member 13 is located on the path of the gas to be measured flowing in the second chamber 102.

In specific application, the gas to be measured enters the second cavity 102 through the gas inlet of the housing 10, and the first heating element 13 in the second cavity 102 is powered on to heat the gas to be measured, so that the temperature of the gas to be measured entering the second cavity 102 is consistent with the temperature in the second cavity 102.

By adopting the technical scheme, the temperature change in the second cavity 102 caused by the gas to be measured can be reduced, so that the influence of the temperature change on the stress of the pressure-sensitive film is reduced, and the measurement precision of the capacitance film vacuum gauge is improved; in addition, the water vapor in the gas to be measured can be removed, and the degassing effect is achieved.

In this embodiment, the first heating member 13 is tapered, the tip of the tapered first heating member 13 is close to the air inlet of the housing 10, and the tail of the tapered first heating member 13 is close to the pressure-sensitive film 11. In specific application, a gas to be measured entering the second cavity 102 from the gas inlet of the shell 10 is heated by the tip of the first heating element 13 when entering the second cavity 102, so that the heating effect is good, and the first heating element 13 always heats the gas to be measured along with the continuous upward flow of the gas to be measured, so that the temperature of the gas to be measured entering the second cavity 102 is ensured to be consistent with the temperature in the second cavity 102, the temperature change in the second cavity 102 caused by the gas to be measured is reduced, the influence of the temperature change on the stress of the pressure-sensitive film is reduced, and the measurement accuracy of the capacitance film vacuum gauge is improved;

specifically, the conical first heating member 13 is formed by winding heating wires, and a gap for the gas to be measured to pass through is formed between adjacent heating wires, so that the first heating member 13 can uniformly heat the gas to be measured.

In some preferred embodiments, a temperature control switch is disposed on the first heating member 13. In specific application, the temperature control switch senses the temperature in the second chamber 102, and when the temperature in the second chamber 102 reaches a predetermined temperature, the temperature control switch is turned on to cut off the circuit, so that the temperature control function is achieved; when the temperature in the second chamber 102 is cooled to the set temperature, the temperature control switch is automatically closed, and the circuit is switched on, so that the first heating element 13 is restored to the normal working state, and the temperature in the second chamber 102 is kept constant.

In some preferred embodiments, the outer side wall of the housing 10 is wrapped with the second heating element 14. In a particular application, the second heating member 14 may heat the entire gauge so that the gauge is constantly at a predetermined temperature. Specifically, the second heating member 14 may be a heating electrode, a heating sheet, or a heating wire.

Preferably, the PID control system can be used to control the first heating member 13 and the second heating member 14, so that the first heating member 13 and the second heating member 14 cooperate to keep the pressure-sensitive film 11 and the vacuum tube at the optimum working temperature, thereby achieving the optimum measurement effect. Specifically, the first heating member 13 and the second heating member 14 may be independent of each other, and controlled by independent PID control systems, or may share one PID control system, and may be adaptively selected according to actual requirements.

In some preferred embodiments, a supporting frame 15 is disposed in the second cavity 102, and the first heating component 13 is disposed on the supporting frame 15. Specifically, the support frame 15 is disposed on an inner side wall of the second cavity 102 and extends into the second cavity 102. The first heating member 13 is fixed by the support frame 15 so as to heat the gas to be measured at a predetermined position, thereby ensuring a good heating effect.

In some preferred embodiments, a baffle 16 is provided at the air inlet of the housing 10. Specifically, the baffle 16 has a plurality of sieve holes, and when the gas to be measured enters the second cavity 102 from the gas inlet of the housing 10, the baffle 16 plays a certain shielding role, so that the gas to be measured slowly enters the second cavity 102, thereby ensuring that the first heating element 13 uniformly heats the gas to be measured.

Preferably, in this embodiment, the tip of the conical first heating element 13 can be directly disposed on the baffle 16, so that the supporting frame 15 can be saved, and the gas to be measured can directly enter the second cavity 102 and be heated by the first heating element 13, so as to reduce the temperature difference between the gas to be measured and the second cavity 102.

In some preferred embodiments, the above capacitance thin film gauge for relieving film stress further includes a connection pipe 17, and one end of the connection pipe 17 is connected to the air inlet of the housing 10. Through this technical scheme, be convenient for be connected the capacitor film vacuum gauge of eliminating film stress and the gaseous container of splendid attire awaiting measuring. Specifically, the connecting pipe 17 is located at the center of the bottom of the housing 10, so that the gas to be measured uniformly enters the second cavity 102 through the connecting pipe 17, and the measurement accuracy is prevented from being affected by the measurement when the gas to be measured is not uniform.

In some preferred embodiments, the capacitance thin film gauge for relieving the thin film stress further comprises an exhaust tube 18, and the exhaust tube 18 is communicated with the first cavity 101. Through this technical scheme, be convenient for be connected the electric capacity film vacuum gauge of eliminating film stress with the vacuum pump.

In some preferred embodiments, the capacitance film vacuum gauge for relieving film stress further comprises a getter 19, and the getter 19 is communicated with the first cavity 101. In a specific application, the getter 19 can absorb residual gas in the first cavity 101, and the stability of the internal and external pressure difference is maintained, so that the measurement accuracy is ensured. The specific type of the getter 19 can be adaptively selected according to actual needs, and is not limited thereto.

Example two

As shown in fig. 3 and 4, the difference between the present embodiment and the first embodiment is: in this embodiment, the first heating member 13 is shaped like a disk, the disk-shaped first heating member 13 is close to the air inlet or the pressure sensitive film 11 of the casing 10, the disk-shaped first heating member 13 is parallel to the pressure sensitive film 11, and the lower surface of the disk-shaped first heating member 13 faces the air inlet.

In the embodiment, the first heating member 13 is designed to be a disc shape and is arranged at a position close to the air inlet of the casing 10, so that the gas to be measured is directly heated by the first heating member 13 to be consistent with the temperature in the second cavity 102 after entering the second cavity 102, or is arranged at a position close to the pressure-sensitive film 11, and the gas to be measured is heated by the first heating member 13 to be consistent with the temperature in the second cavity 102 in the process of flowing to the pressure-sensitive film 11 after entering the second cavity 102, thereby avoiding the gas to be measured from causing the temperature change in the second cavity 102.

Specifically, the disc-shaped first heating member 13 is formed by winding heating wires, and a gap for the gas to be measured to pass through is formed between adjacent heating wires, so that the first heating member 13 uniformly heats the gas to be measured.

EXAMPLE III

The difference between this embodiment and the second embodiment is: in this embodiment, the number of the first heating members 13 is plural.

The following specifically describes the structure and principle by taking two and three first heating members 13 as examples.

As shown in fig. 5 and 6, the number of the first heating members 13 is two. The two first heating members 13 are disposed one above another on the supporting frame 15 of the inner side wall of the second chamber 102, and for convenience of description, the two first heating members 13 are respectively shown as an upper heating member and a lower heating member, and the upper heating member is located above the lower heating member. The size of the upper heating element is larger than that of the lower heating element, and the size refers to the diameter of a disc obtained by the projection of the first heating element 13 in the vertical direction, that is, the projection area of the upper heating element in the vertical direction is larger than that of the lower heating element in the vertical direction, so that the gas to be measured is heated to be consistent with the temperature in the second cavity 102 before reaching the pressure sensing film 11, and the influence of the temperature difference between the gas to be measured and the pressure sensing film 11 on the stress of the pressure sensing film 11 is avoided.

Specifically, go up the center of heating member and the center of heating member down on a straight line, go up the projection of heating member in vertical direction and the projection of heating member in vertical direction down and constitute a complete disc shape, so for go up the heating member and constitute the heating portion of similar frustum shape with lower heating member, can save the heater strip again when guaranteeing the heating effect.

As shown in fig. 7 and 8, the number of the first heating members 13 is three. The three first heating members 13 are spaced from bottom to top on the supporting frame 15 of the inner sidewall of the second chamber 102, and for convenience of description, the three first heating members 13 are respectively represented as an upper heating member, a middle heating member and a lower heating member, the upper heating member is located above the middle heating member, and the middle heating member is located above the lower heating member. The size of the upper heating member is larger than that of the middle heating member, the size of the middle heating member is larger than that of the lower heating member, and the size refers to the diameter of a disk obtained by projecting the first heating member 13 in the vertical direction, that is, the projection area of the upper heating member in the vertical direction is larger than that of the middle heating member in the vertical direction, and the projection area of the middle heating member in the vertical direction is larger than that of the lower heating member in the vertical direction.

Specifically, go up the center of heating member, the center of well heating member and the center of lower heating member on a straight line, go up the projection of heating member in vertical direction, well heating member in vertical direction and the projection of lower heating member in vertical direction constitute a complete circular disk shape, so for go up heating member, well heating member and the heating portion of heating member constitution similar frustum shape down, can save the heater strip when guaranteeing the heating effect.

Specifically, the interval between the upper heating member and the middle heating member is equal to the interval between the middle heating member and the lower heating member, so as to ensure the uniform heating of the gas to be measured.

Similarly, the number of the first heating members 13 may also be four, five, six, and so on, and the specific number is adaptively selected according to actual needs, and the plurality of first heating members 13 form a frustum-shaped heating portion or an approximately conical heating portion, so as to achieve a good effect of heating the gas to be measured.

In summary, according to the capacitance film vacuum gauge for eliminating the film stress, the first heating member 13 is arranged in the second cavity 102, so that the first heating member 13 heats the gas to be measured entering the second cavity 102 from the air inlet of the housing 10, the temperature of the gas to be measured is consistent with the temperature in the second cavity 102, the temperature change in the second cavity 102 caused by the gas to be measured is reduced, the influence of the temperature change on the stress of the pressure-sensitive film is reduced, and the measurement accuracy of the capacitance film vacuum gauge is improved.

In the description herein, references to the description of the terms "one embodiment," "certain embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

What has been described above are merely some of the embodiments of the present invention. It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the inventive concept thereof, and these changes and modifications can be made without departing from the spirit and scope of the invention.

Claims (8)

1. A capacitance film vacuum gauge for eliminating film stress comprises a shell, a pressure sensing film and a fixed electrode, and is characterized by also comprising a first heating element; the shell is provided with an accommodating cavity, the pressure sensing film is arranged in the accommodating cavity, and the accommodating cavity is divided into a first cavity and a second cavity by the pressure sensing film; the fixed electrode is arranged in the first cavity and is parallel to the pressure sensing film, and the fixed electrode and the pressure sensing film form a parallel plate capacitor sensing assembly; the first heating element is arranged in the second cavity and faces the air inlet of the shell; the first heating element is conical, the tip of the conical first heating element is close to the air inlet of the shell, and the tail end of the conical first heating element is close to the pressure sensing film; or, the first heating member is disc-shaped, and the disc-shaped first heating member is close to the air inlet of the shell or the pressure sensing film.

2. The capacitance film gauge for relieving film stress as claimed in claim 1, wherein when the first heating member is disc-shaped, the number of the first heating members is plural, and the plural first heating members are arranged in the second chamber from bottom to top at intervals.

3. The capacitance thin film gauge for relieving film stress as claimed in claim 2, wherein the size of the first heating member positioned below in two adjacent first heating members is smaller than the size of the first heating member positioned above.

4. A thin film stress relieving capacitance thin film gauge as claimed in claim 2 or 3, wherein the spacing between adjacent ones of said first heating members is equal.

5. The capacitive thin film gauge for relieving film stress of claim 1, wherein a temperature control switch is provided on the first heating member.

6. The capacitance thin film gauge for relieving film stress of claim 1, wherein the second heating element is wrapped around the outer sidewall of the case.

7. The capacitance thin film gauge for relieving film stress of claim 1, wherein a support frame is provided in the second chamber, and the first heating element is provided on the support frame.

8. The thin film stress relieved capacitive thin film gauge of claim 1, wherein a baffle is provided at the air inlet of the housing.

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