Patent ID: 8917091
Filing Date: 2014-12-23
Classification: G01C,G01R,G04F

Abstract:
1. A method of calibrating a measurement apparatus with optical pumping functioning, said method comprising: successive injection of at least one current for each of three electromagnetic coils each generating a magnetic field axial to a cell filled with a measuring medium; measuring the magnetic field generated by each of the coils; determining a gain coefficient for each coil, which is a ratio between the magnetic field generated and the current injected; grouping the coils in pairs; simultaneous injection of currents in the coils in each pair of coils, including two currents in one of the coils in the pair and at least one current in the other coil in the pair, in accordance with at least two different states of combination of said currents; measuring the magnetic fields generated by said combinations of currents, an ambient magnetic field being ignored, stopped by shielding or compensated for; and determining at least one angle between the coils according to the magnetic fields measured, the gain coefficients and the currents injected.