We describe the realization of a He-3 magnetometer based on the free p
recession of nuclear spins oriented by optical pumping with a laser. T
he use of a laser diode, directly tuned to 1.083 mu m, and the increas
e of the He-3 nuclear orientation relaxation time with cesium coated c
ells, allow us to elaborate a new original magnetometer, which operate
s sequentially and opens several possibilities of use.