New instruments of the surface water branch, United States Geological Survey

A detailed description of recently developed hydrographic equipment for measuring streamflow, is presented. Each of the following pieces of equipment are described and how the equipment is used to aid accuracy and economics of water measuring procedure. The electromagnetic velocity meter; the acoustical velocity meter; the bubble stream gage; the stream surface follower and recorder. The sonic flood measuring assembly and the digital recorder are depicted in photographs and diagrams. The theory of operation and performance of recorders are discussed. Plans are made for field testing these pieces of equipment and to re-design present concepts.