The multifilter radiometer (MFR) is simply the head from a multifilter rotating shadowband radiometer (MFRSR) mounted on a tower pointing at the surface.
Like the MFRSR, it has six narrowband channels (415, 500, 615, 673, 870, and 940 nm) and one broadband channel. Pointing the head at the surface provides spectral measurements of reflected irradiance. Measurements are taken every 20 seconds, with no averaging performed.