1, the elevation indicates the vertical height of a part of the building relative to the datum (elevation zero), which is the basis for vertical positioning.

According to the choice of datum, elevation can be divided into absolute elevation and relative elevation.

(1) Absolute elevation

Absolute elevation: refers to the elevation with the datum plane uniformly specified by a country or region as the zero point, and the average sea level of the Yellow Sea near Qingdao is specified as the elevation zero point in China; The calculated elevation is called absolute elevation.

(2) Relative elevation

Relative elevation: the starting point of elevation is the height of the main ground of the first floor of the building, and the calculated elevation is called relative elevation.

2. Elevation refers to the distance from a certain point to the absolute datum along the vertical line, which is called absolute elevation. It's short for elevation The distance from a point along the vertical line to an assumed horizontal base surface is called assumed elevation.

Legend: The following is the elevation of a sewage treatment plant engineering course design scheme.

These drawings are the plan and elevation of the sewage treatment plant. The main structures in sewage treatment process include fine grid, pump house, middle grid, grit chamber, primary sedimentation tank, aeration tank, secondary sedimentation tank, contact tank, concentration tank and digestion tank.