Test Results with the EasyQ River Flow Sensor

The EasyQ is a compact sensor that measures river flow velocity and water level (stage). It is appropriate for monitoring river discharge at sites where velocity is needed to supplement stage measurements. In the longer term, its ability to provide sufficient data to automate quality control will improve routine dissemination of river flow data. The EasyQ produces data specifically to support automated data quality control. It measures velocity and signal strength in three cells, thus enabling validation of the data by comparison of the different cells. An integrated pressure sensor plus two independent stage quality parameters provide means to validate and automatically correct stage measurements. A fourth beam enables the EasyQ to detect changes in the depth of the nearby channel. This report summarizes two test comparisons of the EasyQ with nearby sensors. In the White River, comparison of EasyQ velocities with other nearby velocity sensors shows that the EasyQ's velocity measurement is accurate to around 1%. Comparison with a nearby AVM shows that the EasyQ velocity is proportional to the velocity averaged across the full width of the river. This result suggests that an EasyQ's velocity, measured at the side, can produce index velocities appropriate for estimating the discharge of the river. At Fall Creek, the EasyQ stage readings matched a nearby shaft encoder with a standard deviation of 4.7 mm. The EasyQ flagged several of its stage data points bad, and its pressure sensor provided the basis for accurate reconstruction of the missing data.