CN110702301A - A thin film vacuum gauge - Google Patents

Abstract

The invention provides a thin film vacuum gauge, belonging to the technical field of detection equipment, comprising: a casing with a reference pressure chamber inside; a wire, one end extending into the reference pressure chamber of the casing, and the other end extending out of the casing; a getter , suspended in the reference pressure chamber; an electric heating element is arranged inside the getter, and both ends of the electric heating element are connected with the wire. In the thin film vacuum gauge of the present invention, the getter is suspended in the reference pressure chamber. During the process of activating and heating the getter, the getter does not contact other components, so it can be avoided that the getter is heated during the heating process. The problem of high temperature of other components caused by it; and the built-in electric heating element in the getter, so that the heat of the electric heating element directly acts on the getter, so that the heating efficiency of the getter is higher, in addition, the built-in getter The electric heating element inside can also support the getter.

Description

A thin film vacuum gauge

technical field

The invention relates to the technical field of detection equipment, in particular to a thin film vacuum gauge.

Background technique

A vacuum gauge is an instrument for measuring the degree of vacuum or air pressure. According to the different physical mechanisms used in the measurement principle of vacuum gauges, vacuum gauges can be divided into three main categories, namely vacuum gauges using mechanical properties, using gas dynamics effects and using charged particle effects.

Among them, the thin-film vacuum gauge is a vacuum gauge using mechanical properties, and the core component of the thin-film vacuum gauge is a diaphragm in a radial tensile stress state, which separates the external pressure test pressure chamber from the reference pressure chamber. The pressure value in the reference pressure chamber is constant. The change of the pressure in the test pressure chamber will cause the change of the pressure difference between the two chambers. The change of the pressure difference will cause the diaphragm to shift. The diaphragm shift will cause the change of the capacitance value. The corresponding relationship between capacitance and pressure change is formed. Therefore, the air pressure in the reference pressure chamber is the basis of the calculation, and the constant air pressure value directly determines the life and accuracy of the differential pressure sensor.

At present, in order to maintain the set air pressure in the reference pressure chamber of the thin film vacuum gauge, an externally heated getter is usually placed in the reference pressure chamber to maintain the vacuum, and the getter is activated by heating and baking before sealing. Perform circuit assembly and debugging. As shown in FIG. 2 , it is a thin-film vacuum gauge in the prior art. The casing of the thin-film vacuum gauge needs to be provided with a mounting hole for installing the getter, and the mounting hole is communicated with the reference pressure chamber. The getter is provided in the getter housing 8, and the getter housing 8 is mounted on the above-mentioned mounting hole, so that the getter can communicate with the reference pressure chamber. A heater 9 is arranged outside the getter housing. During operation, the heat on the heater 9 conducts the heat to the getter through the getter housing 8, thereby activating the getter and making the getter to the reference pressure. The chamber pressure is adjusted.

However, in the above scheme, the heater temperature at least 450°C when the getter is activated can make the getter play the best effect. During the activation time of the getter, due to heat transfer (conduction, radiation, convection) The function of the sensor makes the shell of the sensor reach at least 250 °C, which will have a certain impact on the terminal and electrode lead of the signal output.

SUMMARY OF THE INVENTION

Therefore, the technical problem to be solved by the present invention is to overcome the defect that the thin film vacuum gauge in the prior art tends to cause the temperature of the outer casing of the sensor to be too high when the getter is activated, so as to provide a method that can perform the getter at a lower temperature. Activated thin-film vacuum gauge.

In order to solve the above-mentioned technical problems, the present invention provides a thin film vacuum gauge, comprising:

housing with reference pressure chamber inside;

a wire, one end extends into the reference pressure chamber of the casing, and the other end extends out of the casing;

The getter is suspended in the reference pressure chamber; an electric heating element is arranged inside the getter, and both ends of the electric heating element are connected with the wire.

As a preferred solution, the electric heating element is a heating wire or a heating sheet.

As a preferred solution, the heating wire is in a spiral shape.

As a preferred solution, a uniform interval is maintained between the getter and the inner wall of the casing.

As a preferred solution, the getter is suspended in the middle of the upper and lower directions of the reference pressure chamber.

As a preferred solution, the wire is a rigid wire.

As a preferred solution, the wire extends outward in a direction away from the membrane sheet inside the reference pressure chamber.

The technical scheme of the present invention has the following advantages:

1. In the thin film vacuum gauge provided by the present invention, the getter is suspended in the reference pressure chamber. During the process of activating and heating the getter, the getter does not contact other components, so it can be avoided that the getter is in contact with other components. The problem that the temperature of other components is too high during the heating process; in addition, the electric heating element is built in the getter, so that the heat of the electric heating element directly acts on the getter, so that the heating efficiency of the getter is higher. The electric heating element in the getter can also support the getter.

2. In the thin-film vacuum gauge provided by the present invention, the wire extends out of the casing. During use, the getter can be easily activated online for many times, and the measurement accuracy of the reference pressure chamber can be improved or Delays the life of the vacuum gauge, thereby greatly reducing the acquisition cost of the product.

Description of drawings

In order to illustrate the specific embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the specific embodiments or the prior art. Obviously, the accompanying drawings in the following description The drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

FIG. 1 is a front cross-sectional view of a specific embodiment of the thin film vacuum gauge provided by the present invention.

FIG. 2 is a front cross-sectional view of a specific embodiment of a thin-film vacuum gauge in the prior art.

Description of reference numbers:

1. Shell; 2. Reference pressure chamber; 3. Heating wire; 4. Conductor; 5. Getter; 6. Film sheet; 7. Pressure test chamber; 8. Getter housing; 9. Heater.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation or a specific orientation. construction and operation, and therefore should not be construed as limiting the invention.

In the description of the present invention, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, unless otherwise expressly specified and limited, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

The present embodiment provides a specific implementation of a thin film vacuum gauge, as shown in FIG. 1 , including: a casing 1, the casing 1 is divided into a reference pressure chamber 2 and a pressure test chamber 7, in the reference pressure chamber 2 It is sealed with the pressure test chamber 7 by the membrane sheet 6 .

A getter 5 is suspended inside the reference pressure chamber 2 , and an electric heating element is arranged inside the getter 5 , and both ends of the electric heating element are connected to the wire 4 . The wire 4 passes through the casing 1 from the reference pressure chamber 2, and the other end extends out of the casing 1; Therefore, when the getter 5 is activated, the power-on operation of the wire 4 can be facilitated.

The wire 4 is a rigid wire, and the rigid wire refers to a hard wire, such as a single-core 2.5 square millimeter copper column or an alloy column, which has the advantages of being easy to maintain the shape and convenient for wiring. The getter 5 can be suspended in the reference pressure chamber 2 by connecting the two connection ends of the electric heating element wrapped with the getter 5 to the wires respectively.

In addition, as an alternative embodiment, the wire 4 can also be a non-rigid member, and another rigid member can be provided in the reference pressure chamber 2, so that the getter 5 is connected to the rigid member to keep the getter 5 suspension fixation.

The electric heating element is a heating wire 3 that maintains a spiral shape. By arranging the heating wire 3 in the getter 5 , the getter 5 can be supported.

In addition, as an alternative embodiment, the electric heating element can also adopt other conventional electric heating elements other than the heating wire 3, such as electric heating plate, electric heating belt, electric heating plate and so on.

Instructions

The thin-film vacuum gauge of this embodiment has the problem of inaccurate testing due to aging during use. It can be corrected online to restore the measurement accuracy to the original state and prolong the life of the vacuum gauge. Specifically, by energizing the wire 4 extending out of the housing 1, the heating wire 3 suspended in the reference pressure chamber 2 is heated, so that the getter 5 wrapped and connected outside the heating wire can be activated, so that the reference pressure chamber can be activated. 2 Maintain the preset vacuum conditions and return to the original state.

The accuracy and service life of the thin-film vacuum gauge of this embodiment are verified by the method of accelerated aging. The thin-film vacuum gauge reactivates the getter 5 after each aging to restore the measurement accuracy of the vacuum gauge to the original state. Five times. Therefore, the lifespan of the thin-film vacuum gauge of this embodiment can be at least four times longer than that of the original thin-film vacuum gauge.

Obviously, the above-mentioned embodiments are only examples for clear description, and are not intended to limit the implementation manner. For those of ordinary skill in the art, changes or modifications in other different forms can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. However, the obvious changes or changes derived therefrom still fall within the protection scope of the present invention.

Claims (7)

1. A thin film vacuum gauge, comprising:

a housing (1) having a reference pressure chamber (2) therein;

one end of the lead (4) extends into the reference pressure cavity (2) of the shell (1), and the other end of the lead extends out of the shell (1);

a getter (5) suspended within the reference pressure chamber (2); an electric heating element is arranged in the getter (5), and two ends of the electric heating element are connected with the conducting wire (4).

2. The thin film vacuum gauge according to claim 1, characterized in that the electric heating element is a heating wire (3) or a heating sheet.

3. The thin film vacuum gauge according to claim 2, characterized in that the heating wire (3) is in a shape of a holding helix.

4. The thin film vacuum gauge according to claim 1, wherein the getter (5) is uniformly spaced from the inner wall of the housing (1).

5. The thin film vacuum gauge according to claim 1, characterized in that the getter (5) is suspended in the middle of the reference pressure chamber (2) in the up-down direction.

6. The thin film vacuum gauge according to claim 1, characterized in that the wire (4) is a rigid wire.

7. The thin-film vacuum gauge according to claim 1, characterized in that the wire (4) projects outwards away from the thin-film piece (6) inside the reference pressure chamber (2).

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