Meteorites contain records of past magnetic fields in the form of natural remanent magnetization (NRM). A key property of meteorite magnetization that provides information about its origin is its dependence on spatial scale. In particular, understanding how the mean remanent magnetization varies from the scale of meteorites to the global scale of their parent bodies would aid in the interpretation of spacecraft magnetometry data. However, the vast majority of meteorite samples whose remanent magnetization have been measured have sizes <10 cm due to the limited size range accommodated by laboratory magnetometers. To address this limitation, we developed a portable magnetometer array that enables remanence measurements of meter‐size meteorites in a non‐magnetically shielded environment. The instrument measures both NRM and induced magnetization using two orthogonal square Helmholtz coil pairs that compensate the vertical and horizontal components of the background magnetic field. An array of four magnetometers mounted on a movable aluminum rail measures the magnetic field at multiple locations around the sample. The instrument is transportable and can be adapted to different sample sizes. After distinguishing the induced component from the remanent component of a sample's total field, the remanence can be estimated from a multipole field inversion combined with nonlinear least squares method. We validated the instrument and data processing on a magnet of known magnetic moment and measured the NRM of a meter‐sized iron meteorite.

中文翻译：

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便携式磁强计，用于对米制陨石进行磁测量

陨石包含自然剩磁（NRM）形式的过去磁场的记录。提供有关其起源信息的陨石磁化的关键特性是其对空间尺度的依赖性。特别是，了解平均剩余磁化强度如何从陨石的尺度到其母体的整体尺度变化，将有助于解释航天器的磁测量数据。但是，由于实验室磁力计只能容纳有限的尺寸范围，因此测量了剩余磁化强度的绝大多数陨石样品的尺寸均小于10厘米。为了解决这个限制，我们开发了一种便携式磁力计阵列，可以在无磁屏蔽的环境中测量米级陨石的剩磁。该仪器使用两个正交方亥姆霍兹线圈对来测量NRM和感应磁化强度，以补偿背景磁场的垂直和水平分量。安装在可移动铝轨上的四个磁力计阵列可测量样品周围多个位置的磁场。该仪器是便携式的，可以适应不同的样本量。在将样本总场的剩余分量与感应分量区分开来之后，可以通过结合非线性最小二乘法的多极场反演来估计剩磁。我们在已知磁矩的磁铁上对仪器和数据处理进行了验证，并测量了米级陨铁的NRM。