Brodbeck C M, Bukrey R R, Hoeksema J T
Department of Physics, Loyola University of Chicago, Chicago, Illinois 60626.
Rev Sci Instrum. 1978 Sep;49(9):1279. doi: 10.1063/1.1135567.
A versatile ac mutual inductance bridge is described which uses integrated circuit operational amplifiers (op-amps) for the measurement of magnetic susceptibilities of ferro-, ferri-, and para-magnetic samples. The circuit employs op-amps both for balancing the bridge and for detecting the differential signal from the sample coil. The response of the circuit is linear over a wide range of sample susceptibilities, and is calibrated directly in absolute units (emu) using a multiturn digital potentiometer. The sensitivity of the instrument for weak paramagnetic samples (1 g) is +/-3x10(-7) emu.
本文描述了一种多功能交流互感电桥，它使用集成电路运算放大器（运放）来测量铁磁、亚铁磁和顺磁样品的磁化率。该电路使用运放来平衡电桥以及检测来自样品线圈的差分信号。电路响应在很宽的样品磁化率范围内呈线性，并且使用多圈数字电位器直接以绝对单位（emu）进行校准。该仪器对弱顺磁样品（1 g）的灵敏度为±3×10⁻⁷ emu。
