This paper describes an experimental and theoretical study of convected pressure fields in air/water two-phase flows. An air/water pipe flow loop was designed with a vertical test section. A detailed experimental evaluation was carried out on the use of differential pressure transducers for wall pressure measurements. It was established both experimentally and theoretically that the dispersed (bubble) phase will only create very low fluctuating hydrodynamic pressures, resulting in major vibrations and instrumentation problems. Detailed laborious transducer designs and tests eliminated these problems, resulting in an accurate differential pressure technique for the study of convected pressure fields related to the bubble motion. Theoretical pressure predictions and auto-and cross-correlation measurements have demonstrated that the measured convected pressure field is caused by slow moving bubbles travelling in the ’entrapment’ boundary layer next to the wall, rather than being a measure of the area averaged bubble velocity.