Which device is correctly paired to the air pollutant it would be used to measure?

Which device is correctly paired to the air pollutant it would be used to measure?

• A. Gas sensor - CO2
• B. Gas sensor - NOx
• C. Particulate counter - CO2
• D. Lidar system - CO2

Answer: (A)

The main idea is that different air pollutants require different instruments, with some devices designed specifically for gases and others for particles. A gas sensor is built to measure the concentration of gaseous pollutants in the air, and carbon dioxide is a gas that is commonly quantified using infrared-based gas sensors (often called NDIR sensors). These devices detect CO2 by how much infrared light the gas absorbs, giving a direct readout of its concentration in parts per million or similar units. That makes the pairing of a gas sensor with CO2 a standard, accurate match for monitoring this gas. Particulate counters are designed to count and size airborne particles, not gaseous molecules like CO2, so pairing a particulate counter with CO2 isn’t appropriate. A lidar system uses laser light to profile aerosols and distances and can be used for some remote sensing applications, but it’s not the typical, straightforward tool for measuring CO2 concentrations in air. NOx measurements usually rely on specialized gas analyzers (like chemiluminescence or electrochemical sensors) designed specifically for nitrogen oxides, rather than a general gas sensor.

The main idea is that different air pollutants require different instruments, with some devices designed specifically for gases and others for particles. A gas sensor is built to measure the concentration of gaseous pollutants in the air, and carbon dioxide is a gas that is commonly quantified using infrared-based gas sensors (often called NDIR sensors). These devices detect CO2 by how much infrared light the gas absorbs, giving a direct readout of its concentration in parts per million or similar units. That makes the pairing of a gas sensor with CO2 a standard, accurate match for monitoring this gas.

Particulate counters are designed to count and size airborne particles, not gaseous molecules like CO2, so pairing a particulate counter with CO2 isn’t appropriate. A lidar system uses laser light to profile aerosols and distances and can be used for some remote sensing applications, but it’s not the typical, straightforward tool for measuring CO2 concentrations in air. NOx measurements usually rely on specialized gas analyzers (like chemiluminescence or electrochemical sensors) designed specifically for nitrogen oxides, rather than a general gas sensor.