The Master4Light mobile control unit from Majantys is for characterizing LEDs in various conditions. Measuring 48 × 36 × 20 cm, it integrates an adjustable source generator with continuous or pulsed current at various amplitudes and frequencies, plus two thermocouple inputs for real-time temperature probes. A spectrophotometer connected to an 80-mm-diameter integrated sphere measures the optical parameters. The software provides access to the measured spectrum and to parameters such as color coordinates, dominant wavelength, correlated temperature and color rendering index. Applications include component sourcing, product evaluation and quality control.