Absolute vector measurements based on the scalar Overhauser sensors POS

Due to the high absolute precision (up to 0.2 nT) and stability (<0.05 nT per year) scalar Overhauser magnetometer POS-1 found wide application in the magnetic observatories and hazard monitoring systems. Presented new modification for measuring the vertical component (POS-3) or the full vector (POS-4) magnetometers based on the switching bias fields methods [1]. We discuss the long-term experience in the testing of magnetic observatories ART (IGF UB RAS) and Paratunka (IKIR FEB RAS). The absolute accuracy of the measurement of vertical component of 10 nT and the use of the presented method is self-calibration, 1-3 nT is achieved. This was tested by matching with fluxgate magnetometer with nonmagnetic theodolite Theo-010. The vertical system titanium frame based on Garrett's Ø110x260 mm solenoid provides long-term stability up to 2 nT/year. The solenoid vertical axis was controlled at liquid levels of 30 angular seconds and with the help of a new high-precision non-magnetic 2D inclinometer providing accuracy of up to 1 arcsec, resolution 0.1 arcsec, temperature of -40 + 60C. The creation of a new small-sized solenoid and Overhauser sensor with dimensions D50x100 mm mounted directly on the theodolite pipe is similar to DIMOVER [2] presented in the report. The primary results of the test, showing the sensitivity modulo the field to 0.02 nTl and better than 0.3 nTl component along the axis of the solenoid are presented.

Conrad Observatory Journal - 2019. - N5. - P.10. - [ISBN: 978-3-903171-05-3, http://www.conrad-observatory.at/zamg/index.php/downloads-en/category/5-cobsjournal]