After an extension, we finally got our hands on the upcoming EGU General Assembly on May 23-27! Although this time our engineers from China are unable to participate in the on-site event, we are thrilled to present online our new experimental results of the HT1800 open-path hygrometer.

Recently, there has been an increasing demand for low-cost water vapor analyzers, specifically for better spatial representative terrestrial ET (evapotranspiration) flux footprints. In response to the challenge, Healthy Photon collaborated with the Institute of Atmospheric Physics, Chinese Academy of Sciences, to jointly develop HT1800 that realizes fast and sensitive measurements of atmospheric water vapor density. HT1800 is suitable for ET flux measurements based on the EC technique for its short response time and high precision.

Field deployment of the HT1800 open-path hygrometer

The preliminary results show that the HT1800 has a precision (1σ noise level) of ~10 μmol mol⁻¹ (ppmv) at a sampling frequency of 10 Hz. The open-path configuration avoids delay or high-frequency damping due to surface adsorption as well as the routine maintenance of sampling peripherals. Meanwhile, using the absorption spectrum in the near-infrared region to measure water vapor density can avoid the complex cross-calibration due to the H2O-CO2 spectral interference in traditional nondispersive infrared (NDIR) analyzers.

For more details, we sincerely welcome you to join the discussion of “A low-cost, open-path water vapor analyzer for eddy covariance measurement of evapotranspiration” (EGU22-4761) held in Session HS6.6: Remotely-sensed evapotranspiration (RS-ET). Our CEO and technical director, Dr. Yin Wang, will be more than happy to meet you there!