Manometers measure a pressure difference by balancing the weight of a fluid column between the two pressures
of interest. Large pressure differences are measured with heavy fluids, such as mercury (e.g. 760 mm Hg =
1 atmosphere). Small pressure differences, such as those experienced in experimental wind tunnels or
venturi flowmeters, are measured by lighter fluids such as water
(27.7 inch H2O = 1 psi; 1 cm H2O = 98.1 Pa).
To calculate the pressure indicated by the manometer, enter the data below. (The default calculation is for a water manometer with a 10 cm fluid column, with the answer rounded to 3 significant figures.):