PR-652-203801-R04 Magnetometer Noise and Resolution

Abstract

Magnetometers are sensors that measure the magnitude and direction of a magnetic field. There are many types of magnetometers available, but they all rely on electromagnetic principles to measure fields. The most common types are Hall effect, anisotropic magneto-resistive (AMR) and fluxgate sensors. The goal of this study is to investigate several magnetometers to evaluate their capability to detect small changes in an ambient field. These small changes are on the order of 10 milligauss (1 �T) and are caused by the inverse-magnetostrictive effect, or Villari effect, from ferromagnetic pipes. The chosen magnetometer must have a low noise signal and a fine resolution to properly measure the field from the inverse-magnetostrictive effect. To evaluate the chosen magnetometers, multiple sets of measurements were made in a stationary magnetic field and the standard deviation of the data sets were calculated. The noise of some sensors was further investigated to verify that it was normally distributed.