Evaluation of Total Pressure Velocimeter

Abstract

An accurate and multifunctional water velocity meter is developed to fullfill the need for the appropriate water velocity measurement in Indonesia. The water flow velocity itself can be calculated using the principle of total pressure in the water flow. The total pressure to be detected for speed is obtained by using the basic workings of the Pitot Tube which is equipped with a pressure sensor in the form of four resistors arranged in a Wheatstone Bridge pattern. The output from the sensor in the form of a small electric current is processed into a digital signal to obtain an accurate reading. In the previous experiment, it was obtained that calm water measurement data resulted in a voltage of 0.03V and 0.21V at a depth of 2 cm and 10 cm from the surface. Whereas in flowing water, the voltage is 0.04V at small currents and 0.09V at heavy currents using a current source from the hydraulic bench. Furthermore, this speed measuring instrument will be calibrated to determine the response of the tool in graphical form and will be used as a digital readout. The calibration process was carried out using a comparison tool, namely orifice and free jet flow with orifice diameter hole of 6 mm which previously obtained a velocity coefficient value of 0.879. In the next research, the total pressure measurement method is expected to obtain data about the turbulence of a flow and turbulence flow with particles (emulsion) and can detect the speed and type of velocity and turbulence in the flow within a wide range.