The battery-operated, portable SpectraDuo is the only available combined spectroradiometer with a photomultiplier-tube (PMT)--based photometer. The detector systems share alignment and viewing optics to ensure the exact same area is sampled regardless of the measurement type. The spectroradiometer features 256 detectors with a spectral resolution of 1.56 nm for accurate spectral measurements of color and luminance. The photometer contains a highly sensitive, photopically corrected PMT for fast low-light-level measurements. This dual instrument has four automated measuring apertures and a wide luminance range of 0.001 to 5,000,000 foot-lamberts. It is well suited for all display measurements and for measuring luminance, contrast, display white-point calibration (RGB), spectral radiance, CIE chromaticity, correlated color temperature, dominant wavelength, Lab/Luv, illuminance, irradiance, luminous and radiant intensity, luminous and radiant flux ,and display response time. Features include a high-resolution touch-screen color display, analog output, SD (secure digital) card measurement storage, rechargeable Li-ion battery (over 12 hours of continuous use), external trigger and USB, RS-232, and Bluetooth wireless connectivity.