Pressure probes or differential pressure probes are often used in conjunction with pressure transducers to measure transient effects in multiphase systems. It is essential that the response of the probe and transducer combination is known to ensure that the measured pressure is a true reflection of the time-varying system pressure. In gas-filled systems, the transducer diaphragm movement can prove to be a significant contributor to the system response and its effect is more pronounced when measuring small fluctuations in high-pressure systems. In liquid-filled systems, where the fluid is incompressible, diaphragm movement will cause amplitude attenuation similar to that experienced in gas-filled systems.