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in botany, a graphic representation of the shape, number, and location of the parts of a flower or leafy shoot by projecting them on a horizontal surface. The diagram of a flower is made on the basis of one or several transverse sections of the bud. Using conventional symbols, the diagram of a flower may show only the parts visible in a cross section (an empirical diagram of the flower) or it may also show not-yet-developed parts or parts that have disappeared (a theoretical diagram of the flower, based on the study of many empirical diagrams). The diagram of a shoot is based on a schematic representation of a transverse section through the vegetative bud.
in design documentation, a document showing in conventional notation the components of an article or installation and the connections or links between components. Diagrams are usually drawn without regard to scale or to the actual spatial arrangement of the components. They may be classified according to the type of components and connections between components as electrical, pneumatic, hydraulic, kinematic, or combination diagrams. They may also be classified according to the purpose for which they will be used.
Block diagrams that define each principal working component of an article or installation and the component’s purpose and interconnections are developed concurrently with the design of the article, before any other type of diagram; they are used in studying the article’s structure and functioning and are referred to when the article is in actual use.
Functional diagrams showing the processes that occur within an article and within individual components are used in studying the functional capabilities of the article, as well as in installation, adjustment, control, and repair work.
Schematic diagrams define the components of the article that constitute a complete set and the interconnections between components; they usually give a detailed representation of the working principle of the article and may serve as a basis for developing other design documents, such as electrical installation blueprints and specification sheets.
Circuit diagrams show connectors between components and the locations of connectors and lead-ins; such diagrams also illustrate methods of laying out, mounting, and fastening conductors, cables, and piping. Others show external connections to other articles; such diagrams are used for the installation and operation of complex units. Diagrams showing the principal parts of a complex and the interconnections between subassemblies when the complex is installed and operated are designed primarily to give a general representation of the complex. Layout diagrams show the relative spatial arrangement of components.
In the USSR the procedure for drawing up diagrams is established by State Standards (GOST).
V. N. KVASNITSKII