Magnetic field gradient measuring instrument - has metallic vapour absorption cells with HF exciter coils and photodetectors giving phase shift measured by phase balancing signal

摘要

The appts. comprises two identical sensors (1, 2) each with an absorption cell (3) containing a saturated vapour, for example Caesium, around which is wound an h. f. coil (4) and acting as a transparent passage for a light beam from a spectral lamp (5) focussed by a conductor (6) through a lens (7) and an interference and polarisation plate (8). Each emergent light beam passes through a second lens (9) and a photo-converter (10), the latter being electrically connected with an amplifier (11) and a frequency divider (13). The h.f. coils (4) are energised by an adjustable generator (16). The two output signals are combined in a phase detector (15) after one has been through a phase shifter (14).