OPERATION MANUAL - Scintrex

System OverviewAs indicated, different components of the same resonant light beam performtwo functions:• the component parallel to the ambient field performs the optical pumping• the perpendicular component detects the coherent precession.Therefore, no pumping is taking place if the light beam (the optical axis) isperpendicular to the ambient field (the equatorial orientation) andconsequently the sensor is not operating. Equally, no light modulation istaking place if the light beam is parallel with the ambient field (the polarorientation) and consequently the sensor is not operating.The second reason for the sensor not operating in the polar orientation is thatthe H 1 field, being parallel to the ambient field, can not induce precession ofthe magnetic polarization.Operating hemispheresThe plane perpendicular to the ambient field divides the sensor operatingzones into two hemispheres - northern and southern operating hemisphere. Inthe northern operating hemisphere the sensor light beam, which propagates inthe direction of the optical axis, Figure B-2, forms an angle from 0° to 90°with the direction of the ambient field. In this hemisphere, the phase shift ofthe Larmor signal amplifier required for the self-oscillation at the peak of theresonance is -90°.TheoryB-3SM-5 Manual - part # 872700 Revision 3