This paper presents a critical analysis of the application of electrical capacitance tomography (ECT) to exploring the behaviour of solids flow during hopper discharge. Particulate media are employed in many areas such as the food industry, civil and chemical engineering etc. This is a report of work on the measurement of parameters that determine hopper flow for several different types of particulate systems, using a hopper of adjustable geometry equipped with ECT sensors. There is a comparison of different data analysis methods including: Bayesian/MCMC spatial modelling; reconstructed measurements analysis; raw data processing and theoretical descriptions. Measurement and interpretation protocols suited to detection of particular flow phenomena are assessed and recommended.