In engineering and drafting, a datum is a reference point, surface, or axis on an object against which measurements are made. These are then referred to by one or more 'datum references' which indicate measurements that should be made with respect to …

2025年1月2日 · Datums are basically the starting point of any measurement—they keep measurements accurate throughout the manufacturing, the assembly, and the quality checks. 1. Primary Datums. When you measure a part, your first …

A datum feature can be a plane, line, or point, which needs to be used selectively depending on the tolerance and feature you need to specify. This page explains the indication symbols and how to establish datums, using three datums, i.e. the datum plane, datum line, …

2024年3月16日 · A Datum is a plane, axis, or point location that GD&T dimensional tolerances are referenced to. Typically, multiple features will be referenced by each datum, so they're a very important part of the whole thing.

2023年4月11日 · ASME Y14.5 (1994) defines a datum as “A theoretically exact point, axis, or plane derived from the true geometric counterpart of a specified datum feature. A datum is an origin from which the location or geometric characteristics of features of a part are established.”

2024年7月3日 · Datum refers to a reference point or surface that is used as a starting point for measuring or referencing other points, lines, or surfaces. It is an essential concept in engineering, surveying, and mapping. There are different types of datums that serve different purposes.

2025年1月15日 · In its simplest terms, a datum line is a reference line used as a starting point for measurements. It’s a crucial tool that allows us to establish consistent and accurate locations, dimensions, and orientations. Think of it as a zero point or a baseline from which all other measurements are taken.

Global datums, such as WGS 84 and ITRF, are typically bound to the center of mass of the Earth (making them useful for tracking satellite orbits and thus for use in satellite navigation systems.

The datum feature, datum, and datum target are the important geometric dimensioning and Tolerancing (GD&T) concept for creating and manufacturing a model. The datum is an imaginary but theoretically perfect surface, line, or points.

2024年6月19日 · In engineering and drafting, a datum is used as a reference point, surface, or axis on an object for making measurements. It serves as the basis for identifying and describing the dimensions and geometry of a target.