Hello, I'm new to these forums and they seemed like an excellent way to have my questions answered. I'll start by saying that I've never had any course that dealt with fluid mechanics (mechanical engineering freshman), so I'm having quite some trouble grasping how readings on an air flow bench are to be correctly made. I'm using wikipedia's top image on its page on air flow benches to try to understand this topic: Firstly, when the air pump is on, what happens with respect to pressure changes in each plenum? Is the pressure change experienced in every point inside each plenum equally, so a difference in the positioning of the manometers wouldn't cause a difference in readings? And what exact readings of the manometers and calculations would you perform to obtain the air flow volume? I apologize for any english related mistakes, I'm not a native speaker. Thanks in advance!