A dispenser unit for a non-gaseous flowable material has a holder for the
flowable material with an aperture therein through which the material can
be transferred between into and out of the holder, and a flow meter for
measuring flow of the material during transfer. The flow meter has a
sensor, for example a differential pressure meter which determines a
pressure difference between two locations which are vertically spaced from
each other within the holder, one above and one below the surface of the
material, at a number of times during the transfer. The meter emits a
signal indicative of the flow from a calculation of the rate of change of
the determined pressure difference.