The construction, use and results obtainable from a relatively inexpensive ratio-type spectro-radiometer are described. The large range of lamp types, sizes and operating modes capable of being measured are discussed. The measurement of absolute spectral irradiance, Hλ is the primary intent of the instrument. However, values for spectral radiance, Nλ and spectral ra-diant emittance, Wx, and spectral radiant power, Pλ, can also be obtained providing source solid angle subtense is calculable. The methods of data taking, reduction and display are discussed. The overall accuracy of the device is presently limited to approximately ±5% (Hλ), primarily because of the standards currently available. While the optics in the device permit use over the 250nm to 2.5 micron spectral region, the needs for present limitation to the 300nm to 1000nm region and possible additions and uses for the instrument are discussed.