A Method to Improve Flow-Velocity Measurements From an Array of Partially Cosine Response Sensors

A groundwater flowmeter whose working principle is based on an array of thermal sensor axes was studied to analyze the errors introduced when the angular response of the sensor axes is partially cosine and varies with flow velocity. It is shown that, although errors due to the partially cosine response can be reduced by increasing the number of sensor axes, the increment in the number of axes introduces some additional errors. A method is proposed to keep the advantages of increasing the number of axes and to minimize the observed additional errors. This method could be extended to other type of arrays whose sensors have a partial cosine response varying with the physical quantity of interest.