online dissolved hydrogen sulfide sensor


Dissolved O3 ProbeThe Hydrogen Sulfide (H2S) Sensor is ideal for measuring H2S in marine and freshwater for scientific research, water quality, waste water and sewage, or environmental monitoring. The H2S sensor can measure to depths of 100m.

The H2S sensor is supported by our range of remote, telemetry data loggers or we can assist in connecting the sensor to your existing data management system.

The H2S sensor has extremely fast measurement time (approximately 1 second), accuracy of 2%, can measure ow concentrations of H2S, and is highly robust.


more details

This amperometric H2S micro-sensor for shallow water has been developed for the in situ determination of dissolved H2S/Sulphide in natural waters. Because of the partial pressure of the gaseous H2S, the analyte is separated by permeation through the membrane.

Inside the sensor the hydrogen sulphide reacts with a redox mediator. The reoxidation at the working electrode causes a current corresponding to the concentration of the dissolved molecular H2S amount.

The sensor has a very short response time of down to 1 second and streaming is not necessary, so that profiling with high resolution is possible. The sensor works highly selective and there are no interferences to analytes like CO, CO2, H2O-vapour, CH4 or NH3. Both salt concentrations of up to 40 g/l and turbid or coloured solutions do not interfere with the signal.

For measuring the total sulphide concentration within a the pH-range between 5 and 8.5, the sensor has to be combined with a pH-sensor and always with a temperature measurement. Except the shallow water version for depths of up to 100 m, a laboratory version is available too.

All sensors are delivered with slope, temperature compensation data and mathematical formulas for calculating the total sulphide amount. The exchange of sensor heads is very easy and could be done by the customer itself. The alternative exchange tip for dissolved oxygen extends the sensors flexibility.


whole system monitoring solutions

Edaphic Scientific is a one-stop shop for a whole system monitoring solution. We provide water quality monitoring systems for researchers and industry.

Our systems not only support dissolved gas sensors, but related sensors such as temperature, weather sensors, and many more.

At Edaphic Scientific we want to work with you from the start of your project through to its completion. We can provide:

  • Assistance with project and experimental design
  • Procurement of all monitoring equipment, including sensors, data loggers and data management software. Edaphic Scientific is a one-stop shop where we can source and find any necessary equipment for your project from our preferred suppliers or third party suppliers
  • Installation and training
  • Ongoing assistance with data interpretation and equipment maintenance
  • Data correction and analysis, including statistical analysis with the R-package
  • Report and publication preparation including tables, figures, graphs, and manuscript writing


advanced data collection and management solutions

Edaphic Scientific recognises the need for flexible and adaptable sensor and data logging solutions for experimental or environmental monitoring projects.

Data can be downloaded directly in the field from data loggers. A direct connection between the data loggers and your computer, via a USB cable, can be used for manual downloading of data.

Alternatively, data can be downloaded over the internet on your iPhone, iPad or desktop computer with the cloud-based, data management software solutions. Through this remote based downloading capabilities, you can download, view and manage your data, and system, anywhere in the world and at anytime.


feature specification
Measurement Principle amperometry, membrane covered sensor
Accuracy better than 2% of the measuring value
Measurement Ranges Type I: 0.05 – 10 mg/l H2S | Type II: 0.5 – 50 mg/l H2S | Type III: 0.01 – 3 mg/l H2S and others on request
Response Time (T90) approx. 1 second
Sensor Lifetime depends on H2S-stress and on sample matrix: 5…9 months
Environmental Tolerance Temperature: 0°C and 30°C | pH range: 0 to 8.5 for H2S measurements, > 8.5 pH for total sulfide measurements
No Cross Sensitivities Against Carbon dioxide (to 25.38 vol.%) | methane (to 5.78 vol.%) | hydrogen (to 0.544 vol.%) | ammonia (to 1000 ppm(v)) | carbon monoxide (to 92 ppm(v)) | carbon bisulphide (to 5 vol.%) | organic solvents (max. 20 Vol.%) | acetic acid (to 1 mol/l) | dimethyl sulphide, HCN
Low Cross Sensitivities Against SO2 (at pH<4): 100 pip SO2 = 1 ppm H2S and against Chlorine: 50 ppm Cl2 = 1 ppm H2S
EC / Salt Interference no signal interferences caused by salt concentrations up to 40 g/l
Polarisation Time 5 to 15 minutes upon initial measurement
Stirring Senstivity no streaming of the membrane necessary, no stirring of the analyte, very low analyte consumption
Power Supply 9 to 30 VDC
Output 0 to 5 V
Sensor Dimensions diameter: 24 mm | length: 235 mm
Housing Titanium
Connector SUBCONN BH-4-MP (others on request)
Depth Rating 100 m | 10 bar

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