Understanding the interdependent nature of pressure, flow and velocity is important when designing a system and a students understanding of these principles will allow them to exploit these outcomes in any design process.
The PA Hilton unit utilises a Pitot tube which is precisely adjusted with a digital vernier slide horizontally and a non digital micrometer vertically. There are two pressure tappings, one in the Pitot tube to measure total pressure, one in the disk to measure static pressure and velocity at the cylinder surface. One disk is a blank, the other has a cylinder (with the pressure tapping) that is in the airflow.
The purpose of this unit is to build up a 3d pressure map of the air as it flows over the cylinder. If the cylinder is the left hand position (blank on the right) the pressure map is drawn close to the cylinder. Swap over the disks to draw the pressure map further away from the cylinder.