RUSSIAN JOURNAL OF EARTH SCIENCES, VOL. 16, ES5001, doi:10.2205/2016ES000577, 2016
V. I. Odintsov, V. G. Petrov
Extremely achievable parameters of quartz torsion variometer magnetometers are investigated. Influence of instability and noise of the opto-electronic converter on a threshold of sensitivity of a magnetometer with the negative feedback (NF) is considered and extreme values of a sensitivity threshold of the magnetometer are estimated for different magnetic materials used, depths of NF and the demanded frequency range of measurements. Criteria for optimization of the sizes and a form of the magnets are determined by a condition of a maximum relation of the magnetic moment to the moment of inertia. Theoretical and experimental estimates of noise level of magnetometers on a base of vicalloy and samarium-cobalt are given. It is shown that for threshold sensitivity of the magnetometer about 1 pT, the frequency range of the magnetometer with a sensor on a base of vicalloy is limited by a frequency about 1.6 Hz, samarium-cobalt – 6.4 Hz. The received values of a frequency and threshold sensitivity for the specified magnetic materials completely meet the requirements of Intermaget for one-second data and are probably the extreme values for quartz variometers with the opto-electronic converter of angular movements.
Received 28 September 2016; accepted 2 October 2016; published 18 October 2016.
Citation: Odintsov V. I., V. G. Petrov (2016), Threshold sensitivity of quartz torsion magnetometers on a base of vicalloy and samarium-cobalt, Russ. J. Earth Sci., 16, ES5001, doi:10.2205/2016ES000577.
Copyright 2016 by the Geophysical Center RAS.