The national standard of magnetic flux density is used for calibration of coil magnetic flux density standards and standard teslameters. The primary coil standard is realized as a Barker type solenoid (quartz frame, single layer winding in four sections). The standard method of NMR forced precession lies in the measurement of frequency fp of proton resonance in the magnetic field with magnetic flux density B. The standard method of NMR with flowing water (nutation method) uses the resonance of protons in flowing water and this method separates in space protons magnetization in strong auxiliary field from realization of resonance effect in measured field and resonance indication in other auxiliary field.
Realized unit | Range (nominal value) | Relative uncertainty (k=2) | Method |
militesla per amper | 0,6 mT.A-1 | 3.10-5 | coil standard |
militesla | 0,1 mT up to 200 mT | 5.10-5 | NMR nutation |
tesla | 0,02 T up to 2 T | 4.10-5 | NMR forced precession |