Inductive noise thermometer: Theoretical aspects
作者:
Heikki Seppa¨,
Timo Varpula,
期刊:
Journal of Applied Physics
(AIP Available online 1993)
卷期:
Volume 74,
issue 2
页码: 771-776
ISSN:0021-8979
年代: 1993
DOI:10.1063/1.354865
出版商: AIP
数据来源: AIP
摘要:
We describe a new noncontacting method for measuring the temperature of electrically conducting objects by sensing the magnetic field noise. When a high‐Qantenna is placed close to a conductive material, e.g., a hot metal plate, the effective noise temperature of the antenna becomes proportional to the temperature of the material. Contrary to the conventional noise thermometer in which a resistor is embedded in the material, the method requires neither galvanic nor thermal contact. If the antenna impedance at different frequencies is known, the temperature of the object can be calculated from the total voltage noise of the antenna. We show, however, that for high‐Qantennae the knowledge of the impedance at resonance is adequate to determine the unknown temperature. Consequently, the temperature of moving objects can be measured via synchronous monitoring of the total noise of the antenna and its impedance at resonance. Since only electrically conductive objects create magnetic field noise, the method is immune to nonconductive contamination of the surface.
点击下载:
PDF
(743KB)
返 回