I work for a manufacturing company. We want to make some improvements to our compressed air system, but we want to establish a baseline of our current efficiency for cost justifications, etc. One planned improvement, is redesigning our current piping layout. We spoke with a consultant who wants to sell us several gauges to measure cfm and psi at various locations in the facility. He claims by measuring cfm and psi at the header nearest compressor, we will be able to determine pressure loss from header to point of usage. Is this possible or is he just trying to sell product? Are there not other variables that need to be considered (ie: temperature, distance in pipe, number of fittings, types of fittings, pipe diameters, etc.) ? I realize we only need ballpark figures for justification, but can we measure pressure loss by only knowing cfm and psi at two given locations?