A gradient magnetometer, using proton free-precession

A Proton Magnetometer With Solid State Switching

“…The switching cycle for proton magnetometers is complicated by the fact that in the normal circuit design the coil tuning capacitor is disconnected during the polarising and current decay period (Aitken and Tite 1962). Such switching is most easily achieved by the use of two electromechanical relays.…”

“…If the output of the amplifier is fed to earphones a very low signal to noise ratio can be tolerated since the overall ear mechanism acts as a narrow band filter and gives a large subjective improvement in signal to noise ratio. A very simple, relatively low gain amplifier (40 dB) requiring no tuning can be used in conjunction with earphones in the 'bleeper' mode (Aitken and Tite 1962).…”

Magnetische Messungen

“…B. von Elektronenresonanzspektrometern beschreibt [37]; ein Eichmarkengeber mit einem Spektrumsgenerator zur Erzeugung der Standardfrequenzen wird in [38] behandelt. Ein weiterer Kernresonanzmagnetfeldmesser für Feldgradientenmessung wird unter [39] beschrieben. Eine besondere Schaltung für Protonenresonanzmessungen bis zu 20 kOe mit Meßbereichumschaltung ohne Sondenwechsel beschreibt [40], ferner einen Kernresonanzmagnetfeldmesser der Alpha-Scientific Lab.…”

A high‐stability fluxgate magnetic gradiometer for shallow geophysical survey applications

“…Attempts were made to apply this type of instrument to shallow geophysics and archaeology where buried features could be revealed by their induced and remanent magnetization (Alldred, 1964). The proton precession magnetometer, however, when applied to archaeological prospection, gave more stable results (Aitken and Tite, 1962;Clark, 1990).…”