Effect of Magnetic Field Dynamics on the Copper‐Constantan Thermocouple Performance

Abstract

This paper presents some results of experimental research addressing the influence of magnetic field dynamics on the copper-constantan thermocouple performance. There are challenges in measuring temperature by thermocouples in a timedependent magnetic field. Although there is considerable experience on the effect of a static magnetic field, there is a lack of awareness of the outcome of a varying field on thermocouple performance. We measured the accuracy of the thermocouple response in an alternating magnetic field for various operational parameters: frequency of the magnetic field, geometry, and length of the thermocouple wire in the field, and magnetic field strength. The effect of each of the operational parameters is discussed. Test results of temperature profile measure by a copper-constantan thermocouple in a varying magnetic field system that was used in a room temperature magnetic refrigeration test bed are demonstrated.

Analysis of room temperature magnetic regenerative refrigeration

“…In our set up we did not completely prevent the thermocouple tip and magnetic refrigerant from movement due to the changing magnetic field. In addition, there is always inherent error in thermocouple measurements [33] in a variable magnetic field. In our test bed, the change in the magnetic field was not synchronized with start and stop of blows.…”

Adiabatic magnetocaloric temperature change in polycrystalline gadolinium – A new approach highlighting reversibility

“…[6][7][8] Besides displaying a typical peak observed in Gd at temperature close to its T c , the T curves from our new test bed measurements display an additional feature between about 290 K and 292 K, which demonstrates the complex spin dynamics of Gd. This phenomenon will be discussed in a separate paper.…”

“…[3][4][5] In this study, a Cernox RTD temperature sensor from Lakeshore Cryotronics is used to carry out the measurements, since thermocouples' readings are disturbed in the proximity of a varying magnetic field. 6 A Cernox sensor is preferred to a thermocouple due to its low magnetic field-induced errors in the 0.3 K to 420 K temperature range with an accuracy of 0.001 K and a time resolution of 1ms.…”

Synthesis and Characterization of Some Useful Thermoelectric Materials

“…The investigations are carried out for the thermo emf generation for each of the three pellets in the temperature range of 190 °C (below the melting point of all three materials) not only in the normal mode but also under the effect of applied electric and magnetic fields. The external parameters (electric and magnetic fields) are considered because sometimes they exist already in the environment of operations of thermo generator elements and due to their pronounced effects on the thermoelectric properties [13][14][15][16][17], even can applied externally.…”