Bubbling fluidised beds are used for a wide variety of industrial processes. As such it is desirable to be able to specify the conditions within the bed. These conditions can be subject to unwanted change in areas such as feedstock or fluctuations in process settings such as gas flow. This paper shows how pressure measurements can be used to characterise changing conditions within a three-dimensional bubbling fluidised bed. These characterisation techniques are then used to show that a linear controller can control the conditions within a bubbling bed. This control is demonstrated to be robust, being insensitive to the gas flow conditions, controller gains and location at which the characterisation measurement is made.