Electrochemical gas sensors are gas detectors that measure the concentration of a target gas by oxidizing or reducing the target gas at an electrode and measuring the resulting current. Different types of electrochemical sensors are potentiometric gas sensors, amperometric gas sensors and electrocatalytic gas sensors. Electrochemical sensor technology offers highly specific gas sensing in the low ppm range for many gases. The Electrochemical gas detector gives long-term dependable service while identifying target gases without the inconvenience or hazards of nuisance trips.

Operating Principle of Electrochemical Gas Sensors

Electrochemical Gas Sensor
Air and target gas diffuse through the diffusion barrier to reach the sensing electrode. The controlling circuit maintains an external operating voltage between the sensing and counter electrodes sufficient to drive the electrochemical reaction. The electrochemical reaction with the target gas generates a current flow between the sensing and counter electrodes. This current is proportional to the target gas concentration and is reversible. The electronic circuit also provides a specific bias potential between the reference and the sensor electrodes in such a manner that no current flows between them. The quick response of the sensor results in continuous monitoring of ambient air conditions.

List of Gases Detectable by Electrochemical Sensors

  • Acetaldehyde (C2H3O), Acetylene (C2H2), Acrylonitrile (C3H3N)
  • Ammonia (NH3), Arsine (AsH3)
  • Bromine (Br2), Butadiene (C4H6)
  • Carbon Monoxide (CO), Carbonyl Sulfide (COS)
  • Chlorine (Cl2), Chlorine Dioxide (ClO2), Epichlorohydrin (C3H5OCl)
  • Diborane (B2H6), Germane (GeH4), Hydrazine (N2H4)
  • Ethanol (C2H5OH), Ethyl Mercaptan (C2H5SH), Ethylene (C2H4), Ethylene Oxide (C2H4O)
  • Fluorine (F2), Formaldehyde (CH2O)
  • Hydrogen 0-1% (H2), Hydrogen PPM (H2), Hydrogen LEL (H2), Hydrogen Bromide (HBr), Hydrogen Chloride (HCl), Hydrogen Cyanide (HCN), Hydrogen Fluoride (HF), Hydrogen Sulfide (H2S)
  • Methanol (CH3OH), Methyl Mercaptan (CH3SH), Dimethyl Sulfide (C2H6S)
  • Nitric Oxide (NO), Nitrogen Dioxide (NO2)
  • Ozone (O3), Phosgene (COCl2), Phosphine (PH3)
  • Sulfur Dioxide (SO2), Silane (SiH4)
  • Tetrahydrothiophene (C4H8S), Thiophane (C4H4S)
  • Vinyl Acetate (C4H6O2), Vinyl Chloride (C2H3Cl)