What type of gas detector is used for detecting carbon monoxide?

The correct option for detecting carbon monoxide is the electrochemical cell. This type of gas detector is specifically designed to sense and measure the concentration of carbon monoxide in the air through a chemical reaction that occurs within the cell. When carbon monoxide enters the electrochemical cell, it reacts with the electrolyte, generating a small electrical current that correlates to the concentration of the gas present.

Infrared analyzers, while useful for certain gases and applications, are not specifically tailored for carbon monoxide detection as effectively as electrochemical cells. Gas chromatographs are complex analytical tools that separate and analyze compounds in a gas mixture, making them more suitable for detailed chemical analysis rather than immediate detection of carbon monoxide. Detector tubes can measure a variety of gases, including carbon monoxide, but they are often less sensitive and provide less real-time data compared to electrochemical sensors.

Thus, when it comes to detecting carbon monoxide specifically, the electrochemical cell is the most efficient and appropriate choice.