2ND-CHANNEL DESIGNS FOR A SINGLE-CHANNEL FLAME PHOTOMETRIC DETECTOR

An existing, one-channel flame photometric detector was modified so that it would operate with higher sensitivity on two channels. To do this, the available primary channel was first changed to holophotal mode by installing a parabolic mirror. Optical access to the flame was then secured for a secondary channel by drilling a coaxial hole through the parabola. Two alternative designs were used for the secondary channel: a light guide and a lens-mirror combination. They were tested with compounds of osmium, lead, sulfur and phosphorus. Both the new primary and either one of the two secondary channels yielded higher light throughput and lower detection limits than the initial, conventional channel.