PIEZOMETER Water flows through the pipe that has an elevation slightly above sea level. Use the piezometer reading to calculate the pressure of the flowing water.

♦  Start where the pressure is known - the surrounding atmosphere. Follow a hydrostatic path to the center-line of the flow of water.

The starting place is outside of the pipe (at Z=0) in air. Standard atmosphere is defined there to be 14.7lbf/in².

p_atm - ρ_airg_o(12 ft) + ρ_waterg_o(12 ft) = p_water

An interesting aspect of the piezometer is that, in effect, the height of a standing column of water tells the pressure of a flowing stream. Both the water in the column and the flowing stream are "static."

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