A novel HCl/HF analyzer

State-of-art, cavity-enhanced analyzer to help solve this long-standing technical problem in volcano science, adapted from an industrial instrument. The Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS) yields a several kilometer path length for absorption. Contains two near-IR tunable diode lasers and is field portable, fast, and precise. The exact trajectory of the laser into the cavity is not critical, making the system immune to small changes in optical alignment from mechanical and thermal perturbations (e.g. vibrations, shock, relative stack motion, etc).