I have a Z-spray and changed the nozzles to get more volume. I did the catch each nozzle for 1 minute and compare with the tee jet book. I was very close and it says i'm spraying .44 oz/1000. In a real situation i seem to be spraying more than that. My pressure and speed are constant, and i'm using a foam marker. Does the tee jet book figure in the overlap of each nozzle on the boom? If I did the 1 gallon and see how far is goes method would you figure your spray width from outside nozzles or actual spray width. If you used outside nozzles you would allow for the overlap on the next pass. thanks guys.