This evanescent wave absorption sensor is an extended ATR probe, with considerably more sensitivity. This evanescent wave absorption sensor consists of a sapphire fiber wound around a vertical PTFE shaft. The ends of the fiber are tapered up to facilitate the coupling of light into and out of the probe.The design permits the adjustment of the interaction length by more than an order of magnitude to accommodate the optical analysis of spectral features with widely different absorption coefficients. Evanescent wave probes are especially well suited to measurements in turbid fluids, alcohol content in beer/wine/liquors, water content in ethanol, and ethanol content in gasoline.
- Mates to light source and spectrometer using 21-02 splice bushings and two 400 μm fiber patch cords
- Choose a longer active fiber length for more highly concentrated solutions