Here are the 28" H2O adjustment factors for the lower test pressures I use (does not take into account any actual calibration test correction factor for my bench, which is 1.035): 28/15 = 1.366 28/13 = 1.468 28/12 = 1.528 28/10 = 1.673 28/9 = 1.764 28/8 = 1.871 28/7 = 2.000
