We describe a novel device which can measure, with low dissipation and high
resolution, the level of a dielectric liquid. This device can also be used
with cryogenic liquids, in particular with liquid helium. The high degrees
of stability and of reproducibility make this apparatus an instrument of p
erformances largely competitive with respect to others commonly used. (C) 1
999 American Institute of Physics. [S0034-6748(99)05102-3].