The right choice of sphere depends on the size of the light source under investigation and the measuring task. Potential measuring errors are minimized with all models in the ISP Series through the optimized ratio between sphere surface and area of the measuring port to yield a high level of measuring accuracy. The small sphere models from Instrument Systems with diameters of 75mm, 100mm and 150mm were specially developed for measuring single LEDs in production and laboratory. The mid-range sizes of 250mm and 500mm are ideal for LED modules or small lamps with a relatively low output. The ISP 1000 has a diameter of 1m and is ideally suited to a wide range of applications. The characteristics of high-power LEDs, large LED modules and lamps can be determined in both measuring geometries. The ISP 2000 is the biggest model in the family and this is the integrating sphere of choice for large luminaires and SSL (Solid State Lighting) products