Assessment of the total radiant power or luminous flux of light sources using integrating spheres is one of the most important tests in light measurement. The inside surface of an integrating sphere is coated with a diffusely reflecting material which guarantees complete integration and homogenization of the emitted radiation. The integrated light is then measured at the detector port.

Instrument Systems has developed a complete series of integrating spheres, available in a wide range of sizes and providing functionality for a broad spectrum of applications. A deciding factor in choosing the appropriate integrating sphere is the maximum dimension of the light source to be measured. Larger sources require the use of larger integrating spheres in order to keep measurement errors to a minimum.

All integrating spheres have a side entrance port for determining luminous flux in the 2π configuration (i.e. for determining emission into the forward hemisphere only). With the larger integrating spheres, the test object can also be mounted in the center, thus permitting measurements in the 4π configuration (i.e. for determining emission in all directions).  

Model Overview:

Model	Diameter	Entrance port on side	Internal lamp	post Features	Application
ISP 75	75 mm	yes	no	can be coupled to LED Station; version available for use with LED Tester	only compatible with standard single LEDs
ISP 250	250 mm	yes	no	CIE 127 compliant for 2π measurements	for all single and high power LEDs as well as small LED modules
ISP 500	500 mm	yes	yes	CIE 127 compliant for 2π and 4π measurements	compatible with all LEDs, mid-sized modules and small lamps
ISP 1000	1000  mm	yes	yes	lamp post for both standing and hanging arrangements; stable mounting platform for large test sources	compatible with all high power LEDs, large modules and lamps

Model specifics