The design of the Venturi in the MPM meter is based on the ISO standard. However, the flow models of the ISO standard is developed for single phase flows only (liquid OR gas), and more sophisticated models are required when oil, water and gas are flowing together.
Advanced Venturi models
MPM are utilizing advanced Venturi models that results from combining physical and mathematical flow models with measurements from the 3D Broadband measurements.
The models have proven successful making extremely accurate measurements in both multiphase and wetgas flowing regimes. The MPM meter does not employ any slip-flow or other empirical model to derive different flow velocities. In fact, the meter determines directly the different velocities for liquid (film and droplet velocities, respectively) and gas. The meter further determines what fraction of the liquid is travelling as a film inside the pipe wall and what fraction is travelling as droplet as well as the liquid film thickness and the droplet size.