Abstract: The invention provides an apparatus and method for fill level monitoring in which the height of contents in a container (10) is monitored. The apparatus comprises an ultrasound reciever (30) and signal processing means (50-56) adapted to receive signals from the receiver, the arrangement being such that the signal processing means (50-56) identifies a first signal (32), in use, which is representative of a wavefront (26) transmitted through the contents of the container (10) independently of the height of the contents in the container (10), and a second signal (34) that is representative of a wavefront (24) that is reflected from the interface (22) between the surface of the contents in the container (10) and the environment above the contents, and in which the signal processing means (50-56) uses the difference in travel time for the two wavefronts (24, 26) to provide a measurement of the level of the contents in the container (10).

Abstract: A non-contact apparatus for monitoring the contents of a container, especially but not exclusively for quality control monitoring purposes associated with high speed packaging processes, comprises a non-contact ultrasound generation member, adapted so as to generate an ultrasound signal within the container (1). A non-contact detection scheme is employed to enable the contents of the container to be monitored by analysing ultrasound signals that have propagated through or round the container (1) either transmitted through or reflected from the containers contents. In use, the apparatus may be adapted to provide information about container fill level (h) or the presence or absence of an insert (14) such as a head forming device by analysing the measured signal profiles generated by a ultrasound detection member (3).