You’ll find the results of my testing in My First (and Probably Last) Catch Cup Experience. They were NOT good. Not only were my catch cup values all over the place (really low efficiencies), but the total area calculated from them was nowhere near my actual area. Or put another way, the Precipitation Rate (Nozzle Flow) calculated by both methods were different. The flow based on Area & Gallons was 12% to 71% higher than what my catch cups measured! And yeah, while catch cups can’t be wrong, their location can be. With mine all over the place, and being able to very accurately measure the actual square feet area of each zone (using my CAD drawings, confirmed with Internet views), I’m using them and abandoning my catch cups.
If you think about it, IF you can measure area accurately, it is a far more accurate method to get AVERAGE flow over your zone. So that’s what I’m using.