SCINTILLATOR LIGHT-SOURCE FOR CHEMICAL SENSING IN THE NEAR-ULTRAVIOLET

A novel chemical sensor based on a light source composed of a radionuc lide and a scintillator is experimentally evaluated. Proper selection of a radionuclide/scintillator combination permits fabrication of a pr actical light source emitting in the ultraviolet (UV). Such a UV light source is critical for chemical sensors which utilize W-excitable chr omophores or fluorophores. Unlike conventional gas-filled discharge la mps, the developed UV source is compact, inexpensive, simple in design , stable, and highly reliable, and it does not require an external pow er source. The utility of the new source was demonstrated through cons truction of sensors for oxygen, This application was selected for expe rimental evaluation of the new light source since oxygen sensors have been characterized well with conventional light sources. Although the scintillator light source is less intense than conventional sources, i ts excellent short-and long-term stability provides a reproducibility of fluorescence measurements of about 0.35% RSD. The stability of the scintillator light source suggests its utility in simple single-beam d etection configurations.