We demonstrate a robust photoacoustic medium for measuring the concentration of ammonia in an aqueous solution. We target the near-infrared (NIR) overtone absorption band (1540 nm) of ammonia with a supercontinuum (SC) laser-based excitation system and an immersion-based acoustic transducer as the detection system. We further present how such a simple system can be used to perform effective in-situ measurements of ammonia over a range of concentrations with a
sensitivity of parts per million (ppm) by volume and linearity of >96%. We demonstrate how the sensing system can be readily tailored to monitor the concentrations of other miscible gases in the aqueous solution.
|Frontiers in Biological Detection
|The Moscone Center
|03/02/2019 → 04/02/2019
|Proceedings of SPIE - The International Society for Optical Engineering