Production and development of quantum sensors of Overhauser magnetometers of geomagnetic field for professional geological exploration of geophysics, archeology, monitoring systems. 20 years of experience in supplying domestic and foreign organizations with ground-based magnetometers and POS–1,2 multichannel gradiometers (POS-1 magnetometer, POS–2 gradiometer) (sensitivity 0.02 nT, accuracy up to 0.1 nT, substance stability 15 years), vector magnetometers POS–3,4 and LOM-2 borehole magnetometers with record gradient resistance (30,000 nT/m) and the dimensions of the omnidirectional sensor up to 34 mm.