The current paper focuses on design and laboratory evaluation of a dual-modality sensor, developed for the needs of the oil and gas extraction industry to measure the composition of heterogeneous mixtures in harsh conditions. The sensor combines ultrasonic and electrical measurement techniques, which are non-destructive, rapid and can potentially provide an on-line industrial measurement. Such a 'dual-modality' measurement could potentially be reliable in a wider range of process conditions. A distinct feature of the sensors presented here is their construction, which makes use of thick-film technology, enabling the construction of multi-layered structures of both conductive and non-conductive layers, some of which may exhibit piezoelectric properties for ultrasonic measurement purposes. These are later fired on a ceramic substrate to provide rugged sensors, capable of working in aggressive industrial environments. Laboratory experiments to investigate the feasibility of the dual-modality sensors were conducted and some comparisons with the theoretical predictions are presented.