1.2.4 - Trace Level Moisture Sensing using a Resonant Photoacousic Sensor with an LED as Light Source

Event
EUROSENSORS 2026
2026-09-06 - 2026-09-09
Zurich
Band
Lectures
Chapter
Optical Sensors
Author(s)
C. Weber, A. Eberhardt, M. Benkendorf, K. Schmitt, J. Wöllenstein - Fraunhofer IPM,Freiburg (Germany)
Pages
54 - 55
DOI
10.5162/eurosensors2026/1.2.4
ISBN
978-3-910600-12-6
Price
free

Abstract

Measuring the water content of gas mixtures is relevant in a large variety of industrial applications ranging from pressurized air to energy or process control applications. Here we present a novel photoacoustic sensor design that uses a LED with a wavelength of 2.7 µm and a radial resonator to achieve detection limits in the single-digit ppm region at averaging time of over 20 seconds. An 8-hour zero-gas measurement shows no drift over this period, enabling even lower detection limits with high averaging times.

Download