The compact and modular X4 light analyzer is designed for use with a PC under remote control operation via USB interface with the supplied OS-X4 software for measurement and display of x,y and u,v CIE chromaticity coordinates, dominant wavelength, complementary dominant wavelength, purity, correlated color temperature, color rendering index and illuminance (lx). The X4 simultaneously measures the light signal integrally and spectrally with a photopic detector and a spectrometer allowing an on-line correction calculation to yield a measurement uncertainty of less than two percent. Color coordinates are indicated with an accuracy of less than 0.005. Adding a Gigahertz-Optik integrating sphere expands the X4’s capability to include luminous (lm) flux measurement. Other available accessories allow average luminous intensity (cd) and luminance measurements to be performed.