Apparatus for detecting and counting flowable particulates having means for feeding these particulates at a uniform speed through a measuring area, defined by radiation emitting and sensing means which are arranged in a plane transverse to the feeding direction of the particulates and such that an even number of fan shaped, overlapping arrays of sensing beams can be generated between the emitting and sensing means, each pair of arrays having two lines of symmetry: the one connecting the convergence points of the fan shaped arrays and the other being the perpendicular bisector thereof.