Lorentz force sigmometry: A contactless method for electrical conductivity measurements
Lorentz force sigmometry: A contactless method for electrical conductivity measurements
复制标题
DOI：
10.1063/1.4716005
复制
发表时间：
2012-05-01
影响因子：
3.2
通讯作者：
Thess, Andres
中科院分区：
文献类型：
--
作者：
Uhlig, Robert P.;Zec, Mladen;Thess, Andres
本通信报告了一种用于非接触式测量固体或导电流体的比电导率的新技术。我们称这项技术为“洛伦兹力Sigometer”，其中新词“Sigometer”源于希腊字母Sigma，通常用来表示电导率。洛伦兹测力仪(Lofos)基于与传统涡流检测类似的原理，但允许更大的穿透深度，并且对传感器和样品之间的距离变化不太敏感。我们阐述了Lofos理论，并计算了由洛伦兹力的测量确定未知电导率所需的校准函数。我们进行了一系列的实验，结果表明，洛伦兹力的测量结果与数值预测非常吻合。将该方法应用于已知电导率为sigma(Al)=20.4MS/m的铝样品和具有sigma(Cu)=57.92MS/m的铜样品，分别得到了sigma(Al)=21.59MS/m和sigma(Cu)=60.08MS/m。这表明，Lofos是一种方便、准确的技术，可以应用于固体和液体导体的过程控制和热物性测量。(C)2012年美国物理研究所。[http://dx.doi.org/10.1063/1.4716005]
The present communication reports a new technique for the contactless measurement of the specific electrical conductivity of a solid body or an electrically conducting fluid. We term the technique "Lorentz force sigmometry" where the neologism "sigmometry" is derived from the Greek letter sigma, often used to denote the electrical conductivity. Lorentz force sigmometry (LoFoS) is based on similar principles as the traditional eddy current testing but allows a larger penetration depth and is less sensitive to variations in the distance between the sensor and the sample. We formulate the theory of LoFoS and compute the calibration function which is necessary for determining the unknown electrical conductivity from measurements of the Lorentz force. We conduct a series of experiments which demonstrate that the measured Lorentz forces are in excellent agreement with the numerical predictions. Applying this technique to an aluminum sample with a known electrical conductivity of sigma(Al) = 20.4 MS/m and to a copper sample with sigma(Cu) = 57.92 MS/m we obtain sigma(Al) = 21.59 MS/m and sigma(Cu) = 60.08 MS/m, respectively. This demonstrates that LoFoS is a convenient and accurate technique that may find application in process control and thermo-physical property measurements for solid and liquid conductors. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4716005]