A unit of pressure equal to the weight of a column of liquid water one inch high at 20° C (1 in. w.g.=0.036 psi).
A unit of measuring pressure or pressure differential (1 in. w.g. = 0.036 psi).
A unit used in measuring pressures. The equivalent measurement in SI is Pascals. 1 in. w.g. = 248.8 Pascals (Pa).