BS ISO 4360:2020 pdf free.Hydrometry一Open channel flow measurement using triangular profile weirs.
BS ISO 4360 This document specifies methods for the measurement of the flow of water in open channels under steady flow conditions using triangular profile weirs. The flow conditions considered are steady flows which are uniquely dependent on the upstream head and non-modular (drowned) flows which depend on downstream as well as upstream levels.Normative references.
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 772, Hydrometry一Vocabulary and symbols Terms and definitions.For the purposes of this document, the terms and definitions given in ISO 772 apply.ISO and IEC maintain terminological databases for use in standardization at the following addresses:一ISO Online browsing platform: available at hts://ww.iso.org/obp 一IEC Electropedia: available at http://www.electropedia.org/ Measuring structure.The structure shall be rigid and watertight and capable of withstanding flood flow conditions without distortion or fracture. It shall be at right angles to the direction of flow and shall conform to the dimensions given in the relevant clauses.The weir comprises an upstream slope of 1 (vertical) to 2 (horizontal) and a downstream slope of 1 (vertical) to 5 (horizontal). The intersection of these two surfaces forms a straight line crest, horizontal and at right angles to the direction of flow in the approach channel. Particular attention shall be given to the crest itself, which shall possess a well-defined corner of durable construction. The crest may be made of pre-formed sections, carefully aligned and jointed, or may have a non-corrodible metal insert,
as an alternative to in situ construction throughout.The dimensions of the weir and its abutments shall conform to the requirements indicated in Figure 2.Weir blocks may be truncated but not so as to reduce their dimensions in plan to less than hmax for the
1:2 slope and 2 hmax for the 1:5 slope.Figure 2 shows the general arrangement of the triangular profile weir.BS ISO 4360 pdf download.