A method includes the following steps: aligning a measuring head with an aerosol container, without relative speed between the two, lowering and centring the head; lowering a measuring device and taking the corresponding measurement at different points of the perimeter of the opening; rotating the measuring device in relation to the container; removing the head, transmitting the data, and removing the unsuitable containers, and a device for performing the method includes a head support having an axial movement device, a centring element; a support for the measuring device, an assembly of measuring arms provided with probes, an arrangement for returning to a rest position, at least one measurement reader, and a rotating device for rotating the measuring device or head.