Franatech - Shallow Water Hydrogen Sulphide (H2S) Micro-Sensor
This amperometric H2S micro-sensor for shallow water has been developed for the insitu 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 200 milliseconds 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.
- Measuring principle: amperometry
- Power supply: 9 ... 30 VDC
- Output: 0 ... + 5 VDC
- Dimensions: diameter: 24 mm, length: 235 mm
- Connector: SUBCONN BH-4-MP (others on request)
- Housing: titanium
- Concentration range:
- type I: 50 μg/l ... 10 mg/l H2S
- type II: 500 μg/l ... 50 mg/l H2S
- type III: 10 μg/l ... 3 mg/l H2S
- or dissolved oxygen sensor tip
- Accuracy: 2% (measuring value) ± 1 digit
- Pressure ranges: 10 bar or laboratory version
- pH-range: 0 ... 8,5 pH
- Response time: t90%: approx. 1 second
- Average life time: 5-9 months (depends on H2S stress and on sample)