Edmund Optics (Barrington, NJ) has released the MLED modular LED test and measurement systems available in three configurations for making measurements on discrete LEDs, arrays, and assemblies. The MLED-2 version includes a 2-inch diameter integrating sphere with a ½-inch diameter input port for making measurements on discrete devices. The MLED-6 system includes the MLED-2 along with a 6-inch integrating sphere assembly, and is suitable for intensity measurements of LEDs and for flux measurements of LED assemblies up to 1.5-inch in diameter. The MLED-12 system consists of the MLED-2 base and a 12-inch integrating sphere with 4-inch diameter port, and is suitable for flux measurements of larger LED assemblies and arrays. The MLED base systems consist of a 2048-element CCD spectrometer, an internal calibration lamp with power supply, and a set of three calibrated neutral density filters. The CCD spectrometer offers a resolution of 1.5 nm with 0.5 nm accuracy over a range of 350 to 1000 nm. The detector can measure luminous flux to 200 lumens using the OD2 filter. Exposure time ranges from 5 ms to 3 sec and stray light is 0.05% at 600 nm.