20230918 20200300 1.0 TRUE Meter The feature uses points to represent data and has five subtypes; flume, magnetic, sonic, venture, and weir. A flume is a fixed hydraulic structure that under free-flow conditions force flow to accelerate in such a way that the flow may be characterized by a known relationship between the sewage level at a single specified location and flow rate. A magnetic meter has a field that is applied to the metering tube, which results in a potential difference proportional to the flow velocity perpendicular to the flux lines. A sonic meter is a volumetric flow meter which requires particulates or bubbles in the flow. A venture is a hot and cold water meter capable of passing some small particulate matter. A weir is a structure consisting of an obstruction such as a dam or bulkhead placed across the open channel with a specially shaped opening or notch. The weir results an increase in the water level, or head, which is measured upstream of the structure. Baltimore County, Maryland Department of Public Works