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OnlineNH3 - Ammonia in gases

Analyzer for online determination
of NH3 in gases

The OnlineNH3 is used for the continuous quantitative determination of ammonia gas (NH3) in gas mixtures.

The system is designed with an integrated dilution step for measurement of very high concentrations (100 - 20000 ppm). Also very low contents in the range of odour treshold (0.1 - 100 ppm) can be measured.

The OnlineNH3 contains a selective amperometric sensor with gas selective membranes, membrane pumps for gas transportation and sample transfer and an integrated PC for continuous recording of measurement data, trends and alarm states. The measurement values can be transmitted via digital (alarm-) and analog outputs into the control room.

Due to an integrated cleaning system the gas analysis in O2 free gases (e. g. biogas) is realized without any drift effects. Because of the stress free mode of operation, the sensor lifetime is considerable increased.

The operation principle makes the OnlineNH3 ideal as a basis for NH3 adjusted regulation of enrichment and cleaning steps.

The instrument is available in the same design for monitoring of hydrogen sulphide (H2S), sulfur dioxide (SO2) or ozone (O3).


  • As basis for NH3 adjusted regulations (e. g. monitoring of air quality in livestock buildings)
  • Environment analysis

Fields of applications:

  • Industrial sectors
  • Animal husbandry
  • Biogas plants


  • Continuous NH3 determination in gases (measurement duration < 5 min)
  • Robust method of analysis
  • Automatic sample dosing
  • Easy calibration steps
  • Selective electrochemical sensor with no cross-sensitivity
  • Software easy-to-use
  • Output value of NH3 as a 4 - 20 mA signal for integration into the local control system
  • Long lifetime of the sensors due to the intermittent gas switching
  • Integrated rinsing steps for measuring of continually fresh samples
  • Active sample intake of the gas up to a distance of 100 m – variable setup of device (wall mounted)
  • Also available for determination of hydrogen sulphide (H2S), sulphur dioxide (SO2) or ozone (O3)

Data sheet


ECH Elektrochemie Halle GmbH
Otto-Eißfeldt-Straße 8
06120 Halle (Saale)

Tel.: +49 345 279570-0
Fax: +49 345 279570-99
Mail: info@ech.de

Sales and Service Center UK

ECH Scientific Limited
Building 69, Wrest Park, Silsoe
Bedfordshire, MK45 4HS
United Kingdom

Tel.: +44 1525 404747
Fax: +44 1525 404848
Mail: info@echscientific.com