OnlineH2S includes a microcontroller-unit for a quantitative determination of the released H2S from the sewer with sensor technology at two or more selected measurement points. It serves as the basis for H2S-adapted regulation of chemicals for water treatment in sewage systems.

The H2S-measurement works with selective electrochemical sensors. The mobile microcontroller includes a data acquisition and data transmission tool, digital and analogue input connections for various easurands as well as digital and analogue alarm output connections (4 – 20 mA) for controlling of dosing pumps for treatment-chemicals, valves etc.

Data can be downloaded by a secured internet transfer line at any time. The control-algorithm includes an intelligent self-learning system of settings, which reacts immediately to local circumstances of the sewage-volume and H2S-carriage.

By evaluating those information, an optimal dosing-value will be determined automatically that will be used for the water treatment with chemicals in the sewage system.

Power supply: mains or battery operated
115 – 230 V, 50 – 60 Hz, 12 VDC (internal battery)
Power input: 40 W maximum, 5 W standby-mode
Measuring range: 0.01…2000 ppm
Typical duration: 24 hour online measurement
Input signal: 4…20 mA analogue (isolation amplifiers) or digital
Output signal: 4…20 mA analogue (isolation amplifiers) or digital
to control the dosing pumps
Protection type: IP65
Dimensions & weight: H2S-Sensor: 200 x 250 x 122 mm, 2 kg
H2S-Controller: 380 x 210 x 600 mm, 10 kg


  • Complete measurement system with data acquisition at two or more measurement-points by H2S-monitoring
  • Calibration related to the concentration of sulphide in waste water
  • High sensitivity (below 0.01 ppm)
  • Suck of the gas sample by a transfer line (up to 50 m length and 10 m depth)
  • Selective electrochemical sensors
  • Low maintenance effort by automatic zero-point-compensation
  • Long life-time of the sensor due to an intermittent gas path control
  • Integrated rinsing steps in order to guarantee current samples for analysis
  • Analogue input connections for various pumps and signals
  • Potential free switching outputs (e. g. sewage pumps)
  • Output signal (4-20 mA) to control dosing pumps for
    water-treatment-chemicals in order to send the signals to a customers’ process control system
  • Direct data acquisition in the device for several months
  • Data transmission via GPRS