datum plane


Also found in: Dictionary, Thesaurus, Medical.

datum plane

[′dad·əm ‚plān]
(engineering)
A permanently established horizontal plane, surface, or level to which soundings, ground elevations, water surface elevations, and tidal data are referred. Also known as chart datum; datum level; reference level; reference plane.
References in periodicals archive ?
The orientation of datum plane B is thus determined by the requirement that it be perpendicular to datum plane C.
By analogy with Figure 4 above, the y axis corresponds to the datum plane, which passes through the center of the hole, denoted as datum B.
Regardless of bore diameter actual size, its axis must be within the specified tolerance of location and must be within a cylindrical zone 0.5mm (0.0196") dia, which is perpendicular to and projects from the datum plane for the bore length.