Description: Mechanical current meters such as cup and propeller current meters are historically the most common type of current meter, used in both irrigation and watershed measurements. Mechanical current meters have moving parts such as a cup wheels or propellers that spin with the force of the water velocity. The number of rotations over a given time results in the water velocity at that sectional profile. Measurements are taken at specific depths and distances across the channel cross section to calculate the flow.
The reliability and accuracy of measurement relies upon the proper function of the mechanical parts. Damage or lack of maintenance can result in friction which impacts the rotation speed of the cups or propellers. However, these systems have been used for decades in developing countries because they can be serviced on-site.
Costs USD Lower: $1,500
Costs USD Upper: $3,000
Accessories: crane, wading rod, automated cable way
Advantages: Relatively inexpensive compared to Current Velocity Meters and ADCP's
Disadvantages: Has moving parts which may cause errors if not maintained properly. Mechnical systems should be occassionally calibrated in a tow tank or some other suitable calibration system.
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