7. Deflection Meters

A deflection meter consists of a vane or plate that projects into the flow and a sensing element that measures the deflection caused by the force of the flow against the vane. These meters are sometimes called drag or target meters. They are usually calibrated to indicate the rate of flow in some desired unit of measure. Head losses through the meter are low to moderate, depending upon design. These meters have no pressure taps to plug. The meters are available commercially and are relatively simple. Their accuracy ranges from moderate to good.