Dual-channel room-temperature direct measuring instrument and method for magnetocaloric effect

Abstract

The invention discloses a dual-channel room-temperature direct measuring instrument and a method for a magnetocaloric effect. The measuring instrument comprises a Dewar tank, a vacuum chamber tube as well as a magnetic field and temperature generator mounted at the lower end of the vacuum chamber tube, wherein a sample rod is arranged in the vacuum chamber tube, a dual-channel sample table for carrying a to-be-measured sample is mounted at the lower end of the sample rod, and the upper end of the sample rod is connected with a sample rod linear guide rail lifting system arranged at the upper end of the vacuum chamber tube through a connecting part; the sample rod linear guide rail lifting system drives the sample rod to move linearly up and down in the vacuum chamber tube so as to change the distance between the to-be-measured sample and the magnetic field and temperature generator. The measuring instrument is simple in structure and convenient to operate and maintain, the complex assembly process in the past is avoided, and the measurement efficiency is improved; parameters required by experiments can be edited and switched at any time according to requirements of the experiments under the control of a control terminal and a linear guide rail controller, the measuring instrument is simpler and quicker to finish the action than an existing instrument adopting computer programming, and the operation difficulty is reduced.

Description

technical field [0001] The invention relates to a magnetocaloric effect measuring device, in particular to a dual-channel room temperature magnetocaloric effect direct measuring instrument and method. Background technique [0002] Since the discovery of the magnetocaloric effect in 1881, magnetic refrigeration as an efficient and reliable green refrigeration technology has attracted widespread attention at home and abroad. Magnetic substances are crystals composed of atoms or magnetic ions with magnetic moments, which have certain thermal motion or thermal vibration. The magnetic moments of ions or atoms in paramagnetic materials are disordered when there is no external magnetic field. After the external magnetic field is applied, the magnetic moments of the atoms are arranged along the orientation of the external magnetic field, ordering the magnetic moments and increasing the degree of order, thereby reducing the magnetic properties of the material. Entropy, so it will re...

AI Technical Summary

Problems solved by technology

However, the measuring instrument still has the following disadvantages: 1. The cost of the equipment and the operation cost are high; 2. The structure of the device is complicated and the operation is cumbersome; 3. The use of electromagnetic field or pulsed magnetic field can only realize the change of the magnetic field by changing the magnitude of the current, and there is a relaxation time , affecting the accuracy of the measurement of the magnetocaloric effect parameters of the material

[0006] Patent Publication No. CN200520008166 proposes a direct magnetocaloric effect measuring instrument using a permanent magnetic field as a magnetic field source; the permanent magnet can provide a magnetic field of 1.4 to 2 Tesla, and the magnetic field strength is relatively It can be stabilized at an accurate value for a long time, but the shortcomings are: 1. The magnetic field provided by the permanent magnet is a fixed value, which cannot meet the adiabatic temperature change under different magnetic fields, and the measurement range is very limited; at the same time, the uniformity of the permanent magnetic field The degree is not high enough, which has a certain impact on the measurement results; 2. The structure and operation of the instrument are relatively complicated

It is not conducive to the improvement of the efficiency of experimental measurement

[0007] Patent Publication No. 201310072922 proposes a magnetic field source with different magnetic field strengths that can be obtained by arranging multiple permanent magnets in different forms, and realizes adiabatic temperature change with temperature changes under different magnetic fields , the measurement device has been greatly improved compared with the past, but the instrument still cannot avoid: 1. The limitations brought by the permanent magnetic field, including the design of the magnetic circuit, the uniformity and stability of the magnetic field strength, and the troubles caused by the size of the magnetic field; 2. , The temperature range of the system is small; at the same time, the structure of the instrument is more complicated, the operation is more cumbersome, and the maintenance of the device is difficult

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