The luminous intensity curve is a curve reflecting the luminous intensity distribution of the luminaire presented for the characteristic section plane or planes of a given luminaire, which are planes passing through the longitudinal (C90) and transverse (Co) axial section of the luminaire.
The diagram shows the luminous intensity distribution of the luminaire in two planes:
- in the vertical plane passing through the longitudinal axis of the luminaire, planes C90-C270,
- in a plane perpendicular to the axis of the housing, C0-C180 plane.
They are defined as shown below.