The time separation is the single most important adjustable variable in a PIV system, as it determines the maximum and minimum velocities that can be measured. The duration of the light pulses determines the degree to which an image is frozen during the pulse exposer. The accuracy of velocity measurements depends upon one's ability to determine the displacement of the particle, over a certain time interval from measurements of the displacement of the image

Fig 3.14: Distributed hole arrangement for uniform seeding distribution.