Editing Magnetometer (section)

====Overhauser effect magnetometer====
The ''Overhauser effect magnetometer'' or ''Overhauser magnetometer'' uses the same fundamental effect as the ''proton precession magnetometer'' to take measurements. By adding [[free radical]]s to the measurement fluid, the [[nuclear Overhauser effect]] can be exploited to significantly improve upon the proton precession magnetometer. Rather than aligning the [[proton]]s using a solenoid, a low power radio-frequency field is used to align (polarise) the electron spin of the free radicals, which then couples to the protons via the Overhauser effect. This has two main advantages: driving the RF field takes a fraction of the energy (allowing lighter-weight batteries for portable units), and faster sampling as the electron-proton coupling can happen even as measurements are being taken. An Overhauser magnetometer produces readings with a 0.01 nT to 0.02 nT standard deviation while sampling once per second.