CN107131960B

CN107131960B - low-temperature measuring device and method

Info

Publication number: CN107131960B
Application number: CN201710434838.5A
Authority: CN
Inventors: 昌锟; 陈顺中; 王晖; 刘建华; 王秋良
Original assignee: Institute of Electrical Engineering of CAS
Current assignee: Institute of Electrical Engineering of CAS
Priority date: 2017-06-10
Filing date: 2017-06-10
Publication date: 2019-12-06
Anticipated expiration: 2037-06-10
Also published as: CN107131960A

Abstract

The invention relates to a low-temperature measuring device and a method, wherein a plurality of conductive fixed contacts (2b) are arranged on the circumference of a fixed disc (2a), four conductive movable contacts (1c) are arranged on the circumference of a movable disc (1b), four thermometer leading-out wires (3a) of each thermometer (3) are arranged along the circumference of the fixed disc (2a) and are electrically connected with the fixed contacts (2b), four measuring lines (4) are led out from the four movable contacts (1c) on the movable disc (1b), when the temperature is measured, a disc shaft (1a) is rotated to enable the four movable contacts (1c) arranged on the movable disc (1b) to be contacted with the four fixed contacts (2b) connected with a certain thermometer (3) on the fixed disc (2a), so that the conductive circuit of the thermometer (3) to be measured is conducted in the whole course, the temperature measurement is carried out through the four measuring lines (4), when the thermometer (3) to be measured needs to be changed, and rotating the disk shaft (1a) to enable the movable contact (1c) to be in electric contact with the fixed contact (2b) connected with the thermometer (3) to be measured.

Description

low-temperature measuring device and method

Technical Field

The invention relates to a low-temperature measuring device and method, in particular to a multi-path temperature measuring method.

Background

In a low-temperature physical experiment, the low-temperature environment, particularly the low-temperature environment in a liquid helium temperature zone (near 4.2K), is very difficult to maintain, various heat insulation measures need to be taken to reduce the heat transfer from the environment to low-temperature parts to the maximum extent, and especially under the condition of needing accurate measurement, the control of the tiny heat transfer from the external environment to a low-temperature experimental object is very important.

The temperature is the most basic physical quantity to be measured in the low-temperature experiment, and the thermometer itself usually adopts a "four-lead method" to realize high-precision measurement, wherein two leads are used for supplying current, and the other two leads are used for measuring voltage, i.e. the thermometer itself needs four measuring wires to be connected from the low-temperature end to the room-temperature end to complete the temperature measurement. In order to ensure the precision of temperature measurement, the thermometer requires good thermal contact with an object to be measured when in use, so that heat transferred by the external environment through the four measuring lines is absorbed by the thermometer and the object to be measured, and the precision of temperature measurement and the actual temperature of the object to be measured are influenced.

in low temperature experiments, in order to ensure the accuracy and integrity of experimental process data, a plurality of temperature measurement points are generally required to be arranged on an experimental object, so that the number of thermometer measurement lines is increased, and the heat transfer problem in the multi-path temperature measurement process needs to be considered. In the existing multi-path temperature measurement technology, all paths of thermometers are mutually independent, each thermometer carries out temperature measurement through four measuring lines, when the number of thermometers is small, the influence of heat transferred through the measuring lines of the thermometers on an experiment is small, and the influence caused by the thermometers can be ignored at the moment; when the number of thermometers is increased, the total heat quantity transferred through the measuring line of the thermometers is excessive to cause the heat flow fluctuation of the experimental object and the thermometers, and thus, the temperature measuring error and the related experimental error are inevitably caused.

There is no relevant measurement technique reported to solve the problem.

Disclosure of Invention

The purpose of the invention is: the device and the method for measuring the low temperature overcome the defects of the prior multi-path temperature measuring technology, and solve the problem of overlarge heat transfer capacity of a multi-path thermometer in a low temperature experiment.

The invention is realized by the following technical scheme.

The invention relates to a low temperature measuring device, comprising: a static disc, a dynamic disc and a thermometer. The static disc and the dynamic disc are made of an electrically insulating material and are arranged coaxially. A plurality of (at least multiples of four) static contacts capable of conducting electricity are arranged on the circumference of the static disc, four movable contacts capable of conducting electricity are arranged on the circumference of the movable disc, a movable disc shaft is fixed at the center of the upper surface of the movable disc, the movable disc synchronously rotates when the movable disc shaft rotates, and the movable contacts are in contact with the static contacts.

Four leading-out wires of each thermometer are arranged along the circumference of the static disc and are electrically connected with the static contacts, then four measuring wires are led out from four movable contacts on the movable disc, when the temperature is measured, the movable disc shaft is rotated to enable the four movable contacts arranged on the movable disc to be in contact with the four static contacts connected with a certain thermometer on the static disc, and thus the whole course conduction of a conductive path of the thermometer to be measured is realized, so that the temperature can be measured through the four measuring wires, when the temperature to be measured is required to be changed for timing, only the disc shaft is rotated, and the movable contacts are enabled to be in electrical contact with the static contacts connected with the thermometer to be measured.

The invention can be communicated with different thermometers by only four measuring wires to realize the measurement of multiple paths of temperatures, and meanwhile, for the measurement of multiple paths of temperatures, only one thermometer is used as a heat transfer medium for an external environment and a low-temperature experimental object in each measurement; theoretically, the number of the thermometers is set to be N, compared with the heat transfer capacity corresponding to the existing multi-path temperature measurement technology, the heat transfer capacity corresponding to the multi-path temperature measurement technology is only 1/N times of the heat transfer capacity, so that the heat transfer between the external environment and a low-temperature experimental object can be greatly reduced, and the measurement precision is improved.

Drawings

FIG. 1 is a schematic view of a moving plate according to the present invention;

FIG. 2 is a schematic view of the structure of the stationary plate of the present invention;

FIG. 3 is a schematic view of a thermometer according to the present invention;

Fig. 4 is a schematic view of the overall structure of the present invention.

Detailed Description

the invention is further described below with reference to the accompanying drawings and the detailed description.

As shown in figure 1, in the invention, a movable disk 1b is made of an electric insulating material, a movable disk shaft 1a is fixed at the center of the upper surface of the movable disk 1b, and four conductive movable contacts 1c are uniformly arranged on the circumference of the movable disk 1 b. In the embodiment, the movable contact 1c is needle-shaped, the length of the movable contact is larger than the thickness of the movable disk 1b, the movable contact 1c penetrates through the movable disk 1b, about 1cm of conductive contacts are respectively exposed on the upper surface and the lower surface of the movable disk 1b, the conductive contacts exposed at the upper end are used for connecting a measuring line 4, and the conductive contacts exposed at the lower end are used for lapping the fixed contact 2b on the fixed disk 2 a. The electrical insulating material used for the movable board 1b may be a wooden board, an epoxy board, or the like.

As shown in fig. 2, the static disc 2a is made of an electrically insulating material, a plurality of thermometers 3 are uniformly arranged on the circumference of the static disc 2a (the number of the thermometers 2 is set to be N, since each thermometer 3 corresponds to four static contacts 2b, the number of the static contacts 2b is 4N, N is a positive integer, and the most preferable value of N satisfies the interval between the adjacent static contacts 2b of 3-5 mm; the static contacts 2b can be electrically conductive, and the electrically insulating material used by the static disc 2a can be a wood board, an epoxy board, and the like.

As shown in fig. 3, one end of the thermometer 3 is connected with four thermometer lead wires 3a for electrical connection terminals required for the "four lead method" measurement, and the other ends of the thermometer lead wires 3a are electrically connected with the stationary contact 2b in sequence.

As shown in fig. 4, the measurement method of the present invention is as follows: thermometer leading-out wires 3a corresponding to all the thermometers 3 are arranged along the circumference of the static disc 2a and are electrically connected with the static contact 2b, then four measuring wires 4 are led out from the four movable contacts 1c on the movable disc 1b, and the static disc 2a and the movable disc 1b are coaxially positioned to complete the installation process.

when measuring the temperature, the rotating disc shaft 1a makes the four moving contacts 1c arranged on the moving disc 1b contact with the four fixed contacts 2b connected with a certain thermometer 3 on the fixed disc 2a, so that the whole conduction of the conductive path of the thermometer 3 to be measured is realized, the temperature can be measured through the four measuring lines 4, and when the thermometer 3 to be measured needs to be changed, the moving contacts 1c are in electric contact with the fixed contacts 2b connected with the thermometer 3 to be measured only by rotating the disc shaft 1 a.

The above examples are provided only for the purpose of describing the present invention, and are not intended to limit the scope of the present invention. The scope of the invention is defined by the appended claims. Various equivalent substitutions and modifications can be made without departing from the spirit and principles of the invention, and are intended to be within the scope of the invention.

Claims

1. A cryogenic temperature measurement device, comprising: a static disc, a dynamic disc and a thermometer; the movable disc is characterized in that a plurality of conductive static contacts are arranged on the circumference of the static disc, four conductive movable contacts are arranged on the circumference of the movable disc, a movable disc shaft is fixed at the center of the upper surface of the movable disc, when the movable disc shaft rotates, the movable disc synchronously rotates, and meanwhile, the movable contacts are in contact with the static contacts; four outgoing lines of each thermometer are arranged along the circumference of the static disc and are electrically connected with the static contact; four measuring lines are led out from four movable contacts on the movable disc, when the temperature is measured, the movable disc shaft is rotated to enable the four movable contacts arranged on the movable disc to be in contact with four fixed contacts connected with a thermometer to be measured on the fixed disc, and a conductive path of the thermometer to be measured is conducted in the whole process, so that the temperature is measured through the four measuring lines, and when the timing of the temperature to be measured needs to be changed, the movable contacts are in electrical contact with the fixed contacts connected with the thermometer to be measured only by rotating the disc shaft;

A multiple of at least four of the plurality of static contacts that are electrically conductive;

The static disc and the movable disc are coaxially arranged;

The static disc and the movable disc are made of electric insulating materials;

The movable contact is needle-shaped, the length of the movable contact is larger than the thickness of the movable disc, the movable contact penetrates through the movable disc, 1cm of conductive contacts are exposed on the upper surface and the lower surface of the movable disc respectively, the conductive contacts exposed at the upper end are used for connecting a measuring line, and the conductive contacts exposed at the lower end are used for lapping the static contacts on the static disc; the interval between adjacent static contacts is 3-5 mm.

2. A low temperature measuring method using the low temperature measuring apparatus of claim 1, characterized by comprising the steps of: when the temperature is measured, the movable disc shaft is rotated to enable the four movable contacts arranged on the movable disc to be in contact with the four fixed contacts connected with a thermometer to be measured on the fixed disc, so that the whole process of conduction of a conductive path of the thermometer to be measured is achieved, temperature measurement can be conducted through the four measuring lines, when the temperature timing to be measured needs to be changed, the disc shaft is rotated, and the movable contacts are in electrical contact with the fixed contacts connected with the thermometer to be measured.