CN106406379A - Temperature control device used for directly heating vacuum gauge to be calibrated in vacuum chamber - Google Patents

Abstract

The invention discloses a temperature control device for directly heating a calibrated vacuum gauge in a vacuum chamber, which belongs to the field of high vacuum measurement calibration. The temperature control device mainly includes a block heating unit, a temperature sensor, an electric control unit, a heating fixture and a heating fixture base; the temperature control device can directly heat the calibrated vacuum gauge inside the vacuum chamber, and the temperature range of the heating can be Large, low heating power; the geometric size of the heating area of the heating fixture conforms to the "second-line field" equipotential line distribution, good temperature uniformity, and due to the vacuum insulation effect, the temperature stability is good, no water circulation cooling system is required, and the temperature of other parts of the vacuum chamber is not affected. Small influence; provides the basis for accurate calibration of high vacuum range vacuum gauges at high temperatures.

Description

A temperature control device that directly heats the calibrated vacuum gauge in the vacuum chamber

technical field

The invention relates to a temperature control device, in particular to a temperature control device that directly heats the calibrated vacuum gauge in a high-temperature high-vacuum calibration system with a vacuum degree greater than or equal to 10 ^-5 Pa and a temperature greater than or equal to 100°C, belonging to high vacuum Metrology calibration field.

Background technique

Vacuum measurement requires accurate and uniform vacuum value, and in order to meet this requirement, the vacuum gauge must be calibrated regularly. Routine vacuum gauge calibration is mostly carried out at laboratory temperature (23°C). However, the actual use environment of the vacuum gauge is varied. If the influence of temperature on the calibration results of the vacuum gauge is not considered, it will lead to inaccurate vacuum measurement. Therefore, it is an important research work to study the influence of temperature on the calibration of the vacuum gauge, to propose a reasonable temperature correction method, and to improve the accuracy of vacuum measurement under different temperature environments, which has strong practical application value. The primary problem to be solved in carrying out this work is to design a temperature control system that can accurately heat the calibrated vacuum gauge in the vacuum chamber. Because temperature changes have a direct impact on the accuracy of vacuum measurement. For the temperature control system of the existing vacuum system, the heating method is mainly to wind the outside of the vacuum chamber of the vacuum system or heat the heating tube for heating. The heating power consumption is high, and the heating temperature generally does not exceed 200 ° C. Some systems also need to be equipped with a water circulation cooling system. , the temperature uniformity and stability inside the vacuum chamber are poor.

Contents of the invention

In view of this, the object of the present invention is to provide a temperature control device that directly heats the calibrated vacuum gauge in the vacuum chamber. The temperature control device directly heats the calibrated vacuum gauge inside the vacuum chamber, and the heating temperature range is large. , low heating power, good temperature uniformity, and due to the vacuum insulation effect, good temperature stability, no need for a water circulation cooling system, and little influence on the temperature of other parts of the vacuum chamber; it provides a basis for accurate calibration of high-vacuum range vacuum gauges at high temperatures .

The purpose of the present invention is achieved by the following technical solutions:

A temperature control device that directly heats a calibrated vacuum gauge in a vacuum chamber, the temperature control device mainly includes a block heating unit, a temperature sensor, an electric control unit, a heating fixture and a heating fixture base;

Wherein, the heating fixture is composed of a concave heating block and a convex heating block; the concave heating block and the convex heating block are both special-shaped column structures, and a semicircular groove is processed on one side of the concave heating block. A semicircular protrusion is processed on one side of the convex heating block;

The block heating unit consists of two pieces, which are closely connected with the concave heating block and the convex heating block of the heating fixture respectively; the heating fixture is fixedly connected with the base of the heating fixture, and the lower heating block of the heating fixture The concave surface is arranged opposite to the upper convex surface of the convex heating block, and a heating cavity of a calibrated vacuum gauge is formed between the lower concave surface and the upper convex surface, and the calibrated vacuum gauge is located in the heating cavity, and the convex heating block The distance from the center of the upper protrusion to the geometric center of the heating fixture is equal to the gap of the heating chamber equal to 1.2 times the radius of the protrusion; the temperature sensor is arranged on the calibrated vacuum gauge, and the temperature sensor and the block heating unit are electrically connected to the electric control unit.

Further, the heating unit has a cuboid structure, and its surface processing flatness is less than 0.5 mm.

Furthermore, the material of the heating unit is oxygen-free copper.

Further, the temperature measurement accuracy of the temperature control sensor is 0.1°C, and the response time to temperature changes is less than 0.1 second.

Further, the electric control unit has a control precision of less than 1% for the power of the heating unit, and a response time of less than 0.1 second.

Further, the material of the heating fixture is oxygen-free copper.

Further, the heating fixture is prepared by an integral processing method.

Further, the contact surface between the heating fixture base and the heating fixture, and the contact surface with the vacuum chamber of the high-temperature and high-vacuum calibration system are made of ceramics.

Beneficial effect

(1) The temperature control device of the present invention can directly heat the calibrated vacuum gauge in the vacuum chamber, and the heating temperature range is large, the power is low, and the temperature uniformity and stability of the heating area are high;

The geometric dimensions of the heating area of the heating fixture conform to the equipotential distribution of the "second-line field model"; the vacuum chamber of the calibrated vacuum gauge is placed in the rectangular shaded area of the heating area in Figure 3, and the geometric center of the heating fixture is the same as the calibrated The geometric center of the vacuum chamber of the vacuum gauge coincides. Since this area is located in the equipotential surface of the "second-line field model", the temperature consistency is the best, which can ensure the best temperature stability, and at the same time have the least influence on the temperature of the outside world, thereby ensuring the Calibrate the uniformity and stability of vacuum gauge heating; provide the basis for accurate calibration of vacuum gauges with high vacuum ranges at high temperatures.

(2) The heating unit of the temperature control device of the present invention is a cuboid structure, which is equivalent to the state-selecting magnet in the "second-line field model", and the heat source is provided by the heating unit of the cuboid structure, which further ensures the stability of the temperature control device. Thermal uniformity and stability.

(3) The temperature control sensor and the electric control unit of the temperature control device of the present invention are all high-precision instruments, and the material of the heating fixture is oxygen-free copper with excellent thermal conductivity, which can effectively reduce the electric control error,

(4) The material of the contact surface of the heating fixture base of the temperature control device of the present invention and the heating fixture, and the contact surface of the vacuum chamber of the high-temperature and high-vacuum calibration system are all ceramics, which can effectively reduce the heat generated by the fixture and the high-temperature and high-vacuum calibration system. transmission, thereby improving the accuracy of temperature control.

Description of drawings

Fig. 1 is a schematic structural view of the high temperature and high vacuum calibration system of the present invention;

Fig. 2 is a schematic structural view of the temperature control device of the present invention;

Fig. 3 is the structural representation of described heating fixture;

Fig. 4 is the equipotential line schematic diagram of described second line field model;

Among them, 1-fine-tuning valve, 2-gas cylinder, 3-first high vacuum shut-off valve, 4-temperature control device, 5-calibration vacuum chamber, 6-second high vacuum shut-off valve, 7-standard vacuum gauge, 8- Calibrated vacuum gauge, 9-heating vacuum chamber, 11-temperature sensor, 12-block heating unit, 13-heating fixture base, 14-concave heating block, 15-convex heating block.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, but is not limited thereto.

Example 1

As shown in Figures 1-2, a temperature control device that directly heats the calibrated vacuum gauge in the vacuum chamber, the temperature control device mainly includes a block heating unit 12, a temperature sensor 11, an electric control unit, and a heating fixture and a heating fixture base 13;

Wherein, the heating fixture is composed of a concave heating block 14 and a convex heating block 15; the concave heating block 14 and the convex heating block 15 are both shaped column structures, and a semicircle is processed on one side of the concave heating block 14 shaped groove, a semicircular protrusion is processed on one side of the convex heating block 15;

The block heating unit 12 is two pieces, which are closely connected with the concave heating block 14 and the convex heating block 15 of the heating fixture respectively; The lower concave surface of the heating block 14 is arranged opposite to the upper convex surface of the convex heating block 15, and the heating cavity of the calibrated vacuum gauge 8 is formed between the lower concave surface and the upper convex surface, and the calibrated vacuum gauge 8 is located in the heating cavity , and the distance from the raised center of the convex heating block 15 to the geometric center of the heating fixture is equal to the gap of the heating chamber equal to 1.2 times the radius of the protrusion; the temperature sensor 11 is arranged on the The vacuum gauge 8 is calibrated, and the temperature sensor 11 and the block heating unit 12 are electrically connected to the electronic control unit.

Wherein, the heating unit is a cuboid structure, and its surface processing flatness is less than 0.5 mm.

The heating unit is made of oxygen-free copper.

The temperature measurement accuracy of the temperature control sensor is 0.1°C, and the response time to temperature changes is less than 0.1 second.

The control precision of the electric control unit to the power of the heating unit is less than 1%, and the response time is less than 0.1 second.

The material of the heating fixture is oxygen-free copper.

The heating fixture is prepared by an integral processing method.

The material of the contact surface between the heating fixture base 13 and the heating fixture and the vacuum chamber of the high-temperature and high-vacuum calibration system is ceramic.

working principle:

As shown in Figures 3 and 4, the size relationship of the heating region of the heating fixture is as follows: AO=BO=CO=a, OM=CD=1.2a, that is, the geometric dimensions of the heating region of the heating fixture conform to the "second-line field model" Equipotential line distribution; the 8 vacuum chambers of the calibrated vacuum gauge are placed in the rectangular shaded area in the heating area in Figure 3, and the geometric center of the heating fixture coincides with the 8 vacuum chamber geometric centers of the calibrated vacuum gauge, because the The area is located in the medium potential surface of the "second-line field model", with the best temperature consistency, which can ensure the best temperature stability and has the least influence on the external temperature;

The electronic control unit is used to control the output power of the heating unit according to the temperature of the calibrated vacuum gauge 8 measured by the temperature sensor 11 and the heating command. The block heating unit 12 heats the heating fixture, and then heats the vacuum chamber placed in the heating fixture. The calibrated vacuum gauge 8 in is heated;

Wherein, said a is one-half of the current spacing of the two-line field model in Fig. 4. Said AO, BO and CO all represent the radius of said protrusion, and said OM represents the center of circle of the protrusion on said convex heating block 15 The distance from the geometric center of the heating fixture, the CD represents the gap of the heating chamber.

The present invention includes but is not limited to the above embodiments, and any equivalent replacement or partial improvement under the principle of the spirit of the present invention will be considered within the protection scope of the present invention.

Claims (8)

1. A temperature control device that directly heats a calibrated vacuum gauge in a vacuum chamber, wherein the temperature control device mainly includes a block heating unit (12), a temperature sensor (11), an electric control unit, and a heating fixture And heating fixture base (13); Wherein, the heating fixture is made up of a concave heating block (14) and a convex heating block (15); the concave heating block (14) and the convex heating block (15) are special-shaped column structures, and in the One side of 14) is processed with a semicircular groove, and one side of the convex heating block (15) is processed with a semicircular protrusion; The block heating unit (12) is two pieces, which are closely connected with the concave heating block (14) and the convex heating block (15) of the heating fixture respectively; the heating fixture is fixed to the heating fixture base (13) Next, the lower concave surface of the concave heating block (14) of the heating fixture is arranged opposite to the upper convex surface of the convex heating block (15), and the heating of the calibrated vacuum gauge (8) is formed between the lower concave surface and the upper convex surface. cavity, the calibrated vacuum gauge (8) is located in the heating cavity, and the distance from the raised center of the convex heating block (15) to the geometric center of the heating fixture is equal to the gap of the heating cavity equal to the 1.2 times the radius of the protrusion; the temperature sensor (11) is set on the calibrated vacuum gauge (8), and the temperature sensor (11) and the block heating unit (12) are all connected to the The electronic control unit is electrically connected. 2. A temperature control device for directly heating the calibrated vacuum gauge in the vacuum chamber according to claim 1, characterized in that: the block heating unit (12) is a cuboid structure, and its surface processing flatness is less than 0.5 mm. 3. A temperature control device for directly heating the calibrated vacuum gauge in the vacuum chamber according to claim 2, wherein the material of the heating unit is oxygen-free copper. 4. A temperature control device for directly heating the calibrated vacuum gauge in the vacuum chamber according to claim 1, characterized in that: the temperature measurement accuracy of the temperature control sensor is 0.1°C, and the response time to temperature changes is less than 0.1 seconds. 5. A temperature control device for directly heating the calibrated vacuum gauge in the vacuum chamber according to claim 1, characterized in that: the control accuracy of the electric control unit to the power of the heating unit is less than 1%, and the response time is less than 1%. Less than 0.1 seconds. 6 . The temperature control device for directly heating the calibrated vacuum gauge in the vacuum chamber according to claim 1 , wherein the heating fixture is made of oxygen-free copper. 7. A temperature control device for directly heating the calibrated vacuum gauge in the vacuum chamber according to claim 1, characterized in that: the heating fixture is prepared by an integral processing method. 8. A temperature control device for directly heating the calibrated vacuum gauge in the vacuum chamber according to claim 1, characterized in that: the contact surface between the heating fixture base (13) and the heating fixture is calibrated with high temperature and high vacuum The contact surface of the system vacuum chamber is made of ceramics.