What do electrochemical cell sensors detect?

• A. The presence of airborne particulates
• B. The pressure of the gas
• C. The amount of heat produced by a reaction
• D. The presence of specific chemicals such as oxygen, hydrogen and others

Answer: (D)

Electrochemical cell sensors detect the presence of specific chemicals by producing an electrical signal from a chemical reaction. A target gas diffuses to the sensor’s electrode, where a redox reaction occurs in an electrolyte. The chemical reaction transfers electrons, generating a current it creates. The size of that current is related to how much of the target gas is present, allowing the sensor to indicate concentration or simply presence. This makes them highly selective for particular chemical species like oxygen, hydrogen, and other gases, depending on the electrode materials and membrane design.

These sensors aren’t meant for counting particulates, measuring pressure, or detecting heat. Particulates are usually detected by optical or filtration methods, pressure by pressure transducers, and heat by thermal or calorimetric sensors.