HT8700 Open-path NH3 Analyzer

HT8700 is based on the state-of-the-art Quantum Cascade Laser Absorption Spectroscopy (QCLAS) technology. The product relies on the laser beam’s multiple reflections between two high-reflection mirrors exposing to the atmosphere, creating an effective optical path-length of several tens of meters. The weak absorption of the laser energy at the spectral peak is extracted from the noise using phase-sensitive lock-in amplification of the modulated laser wavelength/amplitude signal. The trace gas concentration is retrieved based on HealthyPhoton’s innovative absorption spectral characterization algorithm.

HT8700 can be used for Eddy Covariance Flux studies. It can accurately quantify the net exchange flux of atmospheric ammonia in various ecosystems.

Customer case: AFM: Scientists Develop a New Instrument to Measure Atmospheric AmmoniaAE: A diurnal pattern of NH3 dry deposition to cropland in North China agricultural area

  • Details

Features and Benefits

Open Path, Ultra-sensitive, and Fast Response 

Ultra-sensitive NH3 density measurement using laser spectroscopy.

No pump required, no time delays or attenuation from adsorption on the tubing.

Fast response for large NH3 concentration change.

Portable Design for Versatile Field Deployment

- Strong environmental adaptability and vibration resistance.

Enhanced carbon fiber spars that minimize drift.

Heated mirrors that avoid signal loss due to condensation.

Remote Field and Mobile Measurement

- Low power that can be supplied by a solar panel or battery.

Light weight, easy installation and maintenance in remote  field or on a vehicle.






Measurement Range

0-2000 ppbv

Ensure Accuracy Range

0-500 ppbv

Measurement Accuracy

Allan < 0.3 ppbv

@0.1s @zero gas @STD

Default Data Output Frequency

10 Hz

Environment Temperature


Environment Humidity

<99% R.H,non condensing@45℃

Atmospheric Pressure Range

70 -110 kPa

Supply Voltage

24 VDC / 5A


~50 Watts (TYP)


1046 mm x Ø196 mm


10 kg

Data Communication


Data Storage

PC or a third-party data collector

User Interface

UI on the PC

Optional Upgrade Modules

Auto-cleaner, Rainfall Sensing, Mirror Heating

  • Poster: A portable laser-based gas analyzer for simultaneous measurements of N2O, CH4 and CO2

  • Literature: Field comparison of two novel open-path instruments that measure dry deposition and emission of ammonia using flux-gradient and eddy covariance methods

  • Literature: An open-path ammonia analyzer for eddy covariance flux measurement

  • Literature: A significant diurnal pattern of ammonia dry deposition to a cropland is detected by an open-path quantum cascade laser-based eddy covariance instrument

  • Raw Data: HT8700E™ Ammonia Flux

  • Model:HT8700E™ Open-path NH3 Analyzer

    HT8700E™ Open-path NH3 Analyzer

Contact us for more infomation!

Tel:86-156 1892 2826

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