Which statement about electrochemical cell sensors is true?

Which statement about electrochemical cell sensors is true?

• A. The presence of specific chemicals such as oxygen, hydrogen and others
• B. They measure humidity
• C. They measure wind speed
• D. They detect color changes in vapors

Answer: (A)

Electrochemical cell sensors detect targeted chemical species by a chemical reaction that occurs at an electrode inside an electrolyte, producing a current that is proportional to the concentration of the target gas. Because this response relies on interactions with specific chemicals, these sensors are designed to detect particular species such as oxygen, hydrogen, and other hazardous gases. That is why the statement about the presence of specific chemicals like oxygen and hydrogen is the best fit: it captures the essential function of these sensors. They aren’t humidity sensors, which use capacitive or resistive principles to measure moisture levels. They don’t measure wind speed, which is done with anemometers. And they don’t detect color changes in vapors, which would involve optical or colorimetric sensing rather than an electrochemical reaction.

Electrochemical cell sensors detect targeted chemical species by a chemical reaction that occurs at an electrode inside an electrolyte, producing a current that is proportional to the concentration of the target gas. Because this response relies on interactions with specific chemicals, these sensors are designed to detect particular species such as oxygen, hydrogen, and other hazardous gases. That is why the statement about the presence of specific chemicals like oxygen and hydrogen is the best fit: it captures the essential function of these sensors.

They aren’t humidity sensors, which use capacitive or resistive principles to measure moisture levels. They don’t measure wind speed, which is done with anemometers. And they don’t detect color changes in vapors, which would involve optical or colorimetric sensing rather than an electrochemical reaction.