Russian Journal of Earth Sciences Russian Journal of Earth Sciences Russian Journal of Earth Sciences 1681-1208 46618 ОРИГИНАЛЬНЫЕ СТАТЬИ ORIGINAL ARTICLES ОРИГИНАЛЬНЫЕ СТАТЬИ Threshold sensitivity of quartz torsion magnetometers on a base of vicalloy and samarium-cobalt Threshold sensitivity of quartz torsion magnetometers on a base of vicalloy and samarium-cobalt Odintsov V I Odintsov V I Petrov V G Petrov V G N. V. Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences, Moscow, Russia ru N. V. Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences, Moscow, Russia ru N. V. Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences, Moscow, Russia ru N. V. Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences, Moscow, Russia ru 16 5 1 6 29 10 2021 https://rjes.ru/en/nauka/article/46618/view

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.

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.

 Quartz magnetic variometer sensitivity frequency range Quartz magnetic variometer sensitivity frequency range

Askerov, E. N., et al. CAIS digital automatic measuring station // Geophysical Equipment, issue 91, Mikhaylov G.~N. (Ed.) - Moscow: Nedra., 1989. - p. 3. Askerov, E. N., et al. CAIS digital automatic measuring station // Geophysical Equipment, issue 91, Mikhaylov G.~N. (Ed.) - Moscow: Nedra., 1989. - p. 3. Bobrov, V. N. The universal highly stable sensing device with a zero temperature coefficient for the magnetometers, variometers and microvariometers recording any component of a terrestrial magnetic field // Terrestrial Magnetism of II. Theoretical Bases of a Magnetometric Research Technique of Crust and Geomagnetic Measurements, IZMIRAN, issue 18(28) - Moscow: IZMIRAN., 1961. - p. 55. Bobrov, V. N. The universal highly stable sensing device with a zero temperature coefficient for the magnetometers, variometers and microvariometers recording any component of a terrestrial magnetic field // Terrestrial Magnetism of II. Theoretical Bases of a Magnetometric Research Technique of Crust and Geomagnetic Measurements, IZMIRAN, issue 18(28) - Moscow: IZMIRAN., 1961. - p. 55. Bryunelli, B. E., et al. Observations of short period variations of an electromagnetic field of the Earth, // Izvestija Academy of Sciences of the USSR, Geophysics, 1959. - no. 8 - p. 1206. Bryunelli, B. E., et al. Observations of short period variations of an electromagnetic field of the Earth, // Izvestija Academy of Sciences of the USSR, Geophysics, 1959. - no. 8 - p. 1206. Hegymegi, L., Drimusz, L., Koros, Z. Eotvos Institute DIMARS Quartz Magnetometer // Proc. of the Int. Workshop on Magnetic Observatory Instruments, Ottawa, Canada, 30 July-9 August 1986 - Ottawa: IWMOI., 1986. - p. 25. Hegymegi, L., Drimusz, L., Koros, Z. Eotvos Institute DIMARS Quartz Magnetometer // Proc. of the Int. Workshop on Magnetic Observatory Instruments, Ottawa, Canada, 30 July-9 August 1986 - Ottawa: IWMOI., 1986. - p. 25. Jankowski, J., et al. Long-Term Stability of a Torque-Balance Variometer with Photoelectric Converters in Observatory Practice, // Geophysical Surveys, 1984. - v. 6 - no. 3-4 - p. 367. Jankowski, J., et al. Long-Term Stability of a Torque-Balance Variometer with Photoelectric Converters in Observatory Practice, // Geophysical Surveys, 1984. - v. 6 - no. 3-4 - p. 367. Klyuev, A. S. Automatic Control - Moscow: Energy., 1973. - 391 pp. Klyuev, A. S. Automatic Control - Moscow: Energy., 1973. - 391 pp. Marianiuk, J. Photoelectric Converter for Recording the Geomagnetic Field Elements: Construction and Principles of Operation - Poland: Publ. Inst. Geophys. Pol. Acad. Sci.., 1977. - 114 pp. Marianiuk, J. Photoelectric Converter for Recording the Geomagnetic Field Elements: Construction and Principles of Operation - Poland: Publ. Inst. Geophys. Pol. Acad. Sci.., 1977. - 114 pp. Odintsov, V. I., Kolesnik, V. E. Digital magnetovariation station CMVS-2 // Geomagnetic Researches - Moscow: Radio and Communication., 1982. - p. 22. Odintsov, V. I., Kolesnik, V. E. Digital magnetovariation station CMVS-2 // Geomagnetic Researches - Moscow: Radio and Communication., 1982. - p. 22. Rabinovich, S. G. Galvanometric Autocompensation Devices - Moscow: Standards Publishing House., 1972. - 36-40 pp. Rabinovich, S. G. Galvanometric Autocompensation Devices - Moscow: Standards Publishing House., 1972. - 36-40 pp. Yanovsky, B. M. Terrestrial Magnetism of II. Theoretical Bases of a Magnetometric Research Technique of Crust and Geomagnetic Measurements - Leningrad: Publishing house of the Leningrad University., 1963. - 392-413 pp. Yanovsky, B. M. Terrestrial Magnetism of II. Theoretical Bases of a Magnetometric Research Technique of Crust and Geomagnetic Measurements - Leningrad: Publishing house of the Leningrad University., 1963. - 392-413 pp.