InfraSnow SSA Sensor:
The world’s first hand-held device to measure snow specific-surface-area (SSA):
The InfraSnow Sensor was developed in close collaboration with the Swiss Federal Institute for Snow and Avalanche Research (SLF) in Davos. This is the first hand-held device that can measure snow specific-surface-area (SSA) at fractional cost of existing bulky laboratory devices.
The method consists of diffuse near-infrared reflectance measurements using a compact integrating sphere setup to derive SSA. Diffuse reflectance is measured at NIR wavelengths, where impurities have only a weak influence on the reflectance of snow. For a sufficiently thick snow block, there exists a unique correlation between diffuse hemispherical reflectance and SSA according to multiple-scattering radiative transfer theory.
Specifications
SSA range: 2.5 to 80 1/mm
Snow density range: 50 to 685 kg / m3
Measurement wavenlength: 945 nm
Battery run time: > 10 hrs
Temperature range: -25..+60 °C
Memory size: 325 samples
Battery: 3 x 1,5 V AAA cells
Data download: via USB
Display: 102 x 64 px with backlight
Measurement surface: 38 mm Sphere
Literature
Wolfsperger, F., Ziegler, S., Schneebeli, M., Löwe, H. (2022). Evaluation of the InfraSnow: a handheld device to measure snow specific surface (SSA). Poster at the IGS International Symposium on Snow, Davos.
Gergely, M., Wolfsperger, F., and Schneebeli M., 2014: Simulation and Validation of the InfraSnow: An Instrument to Measure Snow Optically Equivalent Grain Size. IEEE Transactions on Geoscience and Remote Sensing.
Wolfsperger, F.; Rhyner, H.; Schneebeli, M., 2018: Pistenpräparation und Pistenpflege. Das Handbuch für den Praktiker. 232 p., WSL-Institut für Schnee- und Lawinenforschung SLF