We are currently using a manometer (DWYER SERIES 475 MARK III) to measure pressure loss in our current product. We’re measuring in ranges of 2(in. WC) thru 3.5(in. WC) and not loose more than 0.35(in. WC) /min. We’re have a so-called sealed unit which we use to evaluate are measuring system. But have had issues, different readings, when measuring in different rooms. Currently we make measurements in an environmental chamber where there is limited air flow. And our repeatability as far as leak measurement has been fairly good, but there is day to day variation. Currently we estimate +/-0.1(in. WC) in our reading. This is a problem when we have a leak at 0.3(in. WC). Any suggestions on having more accurate results?