dissolved hydrogen sulfide (H2S)
The 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.
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 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.
|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|
|Connector||SUBCONN BH-4-MP (others on request)|
|Depth Rating||100 m | 10 bar|