A manually actuated sampling pipette including a piston designed to undergo a dispensing movement during which a first elastic return is loaded, followed by a purge movement during which a second elastic return is loaded, and comprising an electronic device that receives a switching signal notifying passage of the piston through a predetermined position along its dispensing distance or its purge distance, position in which the elastic returns have a predetermined deformation. The pipette also includes a switch that outputs the signal to the electronic device. Furthermore, an elastic support is included which is capable of deforming under the effect of the axial pressure applied by the operator, and the pipette is designed such that deformation of the support, generating switching, is caused when the intensity of the axial pressure is greater than the intensity bringing the elastic returns to their predetermined strain level.