Not sure what you need to know if the project is near completion, but the terms you inquired about can be expained as follows:

In any fluid stream, there are two pressures present. The velocity pressure is the pressure exerted by the flowing mass in the direction of flow but it can't be measured alone. The second pressure is the static pressure which acts in all directions, and is the pressure that is exerted by the fluid on the walls of the duct or pipe.

The measurements need to be taken in a long enough section of tube or duct so that the flow stream is smooth, not turbulent.

If a sensing tube is placed in the stream parallel to the flow with an opening facing upstream, this probe will register the total pressure of the system, both velocity pressure and static pressure.

If another probe is inserted at right angles to the flow, this will register only the static pressure.

If the two probes are connected to a device (a manometer) so that the pressures oppose one another, the effect is to subtract the static pressure from the total pressure picked up by the first probe and the resultant reading gives the velocity pressure.