[en] This kind of separator is operating without matrix in a cascade arrangement of conventional electromagnets. It is most suitable for continuous extraction of paramagnetic particulate solids in liquid suspensions. The water-cooled coils are supported by an iron-yoke with an adjustable air-gap. A one-stage device of laboratory size has been worked out in order to achieve measurements of the magnetic field intensities distributions. Then efficiency measurements were first carried out with a reference magnetite particles suspension in water, without sludge bleeding. As representatives of paramagnetic solids, manganese dioxide, copper oxide and a ruthenium oxide colloid in water are chosen, at concentrations ranging from 100 to 2000 ppm. Efficiencies were measured with continuous and periodical sludge bleedings. Results of such measurements are discussed