Diffuse infrared background radiation measurements have traditionally been carried out across broad wavelength bands, primarily because there seldom appeared to be sufficient energy available in individual spectral lines to make such observations possible. In the past few years, far-infrared searches for spectral line background radiation have become possible, and considerably greater use of these capabilities will become available in the next few years. The promise of this kind of observation is reviewed.
STRAY RADIATION MEASUREMENTS AT PARTICLE ACCELERATOR SITES