Integrating Sphere
The simpler way to measure the total luminous flux of lamps and luminaires is to use an integrating sphere photometer system.
It is a device to perform spatial integration of flux optically, thus the total luminous flux can be measured with one fixed photometer head and measurement can be instant. An integrating sphere photometer is calibrated with a total luminous flux standard lamp.
A test light source is measured by comparison to a standard lamp calibrated for total luminous flux.
