The Hall Flowmeter is a modified pitot tube which averages the the velocity of flow across the diameter of the pipe carrying the water. That means only one reading is required to provide an accurate measurement. The pitot tube is attached to an inverted U-tube water manometer. The manometer scale is calibrated to give a differential reading between the Static Pressure of the pipe, and the Flow or Velocity Pressure.
This reading indicates the amount of water passing through the pipe in Gallons Per Minute (GPM), per square inch of cross-sectional area, as measured along the inside diameter.
The Hall Flowmeter has been rigorously tested for accuracy at several hydraulics testing laboratories, at major universities in California. It is a practical, easy-to use instrument to measure flow velocities. It is used in conjunction with power measurements taken from the pump drive motors, to calculate over-all plant efficiency.
The instrument can be inserted through a corporation stop cock, without shutting down the pump and disturbing the water supply. (See below)
The complete user instructions are available by clicking this link:
Hall Tube Instruction.complete.optimized PDF File 1.5 MB