Discharge characteristics of triangular-notch thin-plate weirs

The triangular-notch, thin-plate weir is a convenient, inexpensive, and relatively precise flow-measuring instrument. It is frequently used to measure the flow of water in laboratories and in small, natural streams. The purpose of this report is to present a comprehensive analysis of the discharge characteristics of triangular-notch weirs. Previously-published data are analyzed in the light of the effective-head concept, and a new discharge formula is proposed. Coefficients are recommended, and requirements for precise measurements are described. Limits of applicability are discussed. The report includes an extensive review of the literature of triangular-notch weirs.