A spectrophotometer includes a plurality of LEDs arranged in a circular array, each having a calibrated power input determined by the use of pulse width modulation and each having a unique wavelength band determined by the utilization of a unique fluorescent phosphor coating or lens. At least one of the LEDs comprising a phosphor-free high energy UV LED. Light reflected to the spectrophotometer is divided into predetermined wavelength ranges through the utilization of a linear variable filter and photo detectors wherein the analog signal from a photo detector is converted to a digital value through the use of auto-ranging gain technique.