STARR is the national reference instrument for spectral reflectance measurements of spectrally neutral, non-fluorescent samples at room temperature.
The illuminator has two sources, a xenon (Xe) arc lamp and a quartz-tungsten-halogen (QTH) incandescent lamp, order-sorting filters, a shutter, a single-grating monochromator, a parabolic mirror, a chopper, and a polarizer. An in-plane goniometer is used for bi-directional measurements, meaning the sample normal, illumination axis, and receiver axis are all in a horizontal plane. The receiver is attached to the goniometer and has a precision aperture, a lens, and a photodiode detector, either silicon (Si) or extended indium-gallium-arsenic (InGaAs). An integrating sphere is used for directional-hemispherical measurements, and can accommodate Si and extended InGaAs photodiode detectors.