Abstract: A dual-wavelength absorption detector is provided. The detector includes an electronics section, a three branched optical guide and a detector-cell. Each branch of the optical guide has a plurality of fibers, and at one end the branches are separated and connected to different portions of the electronics section. Two of the three branches are terminated next to LEDs having different wavelengths, a measuring wavelength and a reference wavelength. The third branch is terminated next to a photodetector. At the opposite end of the optical guide the three branches are combined to form a common end which is terminated within the detector-cell. The detector-cell includes a continuous-flow sample cell connected to a sample line. Within the detector-cell, the common end's fiber ends are held at a fixed location on one side of the sample cell with a concave mirror being located on the opposite side.

Abstract: A continuous-wavelength absorption detector adapted for continuous-flow detection is provided. The detector includes an electronics section, a bifurcated optical guide and a detector-cell. Each branch of the optical guide has a plurality of fibers, and at one end the branches are separated and connected to different portions of the electronics section. One of the branches is terminated next to a source for producing illumination to irradiate sample material and the other branch is terminated next to a detector for producing an absorption spectrum signal. At the opposite end of the optical guide the fibers of the two branches are combined to form a common end which is connected to the detector-cell. The detector-cell includes an approximately vertically aligned continuous-flow sample cell which is connected to a sample line and also includes a concave mirror.