Which method is effective in measuring the concentration of flammable vapors during purging?

Gas chromatography is an effective method for measuring the concentration of flammable vapors during purging because it allows for precise detection and quantification of specific gas components. This technique separates the gaseous components of a mixture based on their interactions with a stationary phase and a mobile phase, enabling accurate measurement of the concentration of flammable vapors.

In industrial settings, such as during purging operations where flammable vapors need to be monitored, gas chromatography provides detailed and reliable data. It can differentiate between various gases and vapors, making it particularly useful when assessing the safety of an environment. The ability to provide quantitative results aids in determining if the concentration of flammable vapors is within safe limits, thus playing a crucial role in fire hazard management.

The other methods mentioned, such as thermal imaging, smoke detection, and radiographic testing, do not provide the specific concentration measurements required for assessing flammable vapor levels. Thermal imaging is primarily used for detecting heat patterns and identifying potential hot spots, smoke detection focuses on the presence of smoke particles rather than specific gas concentrations, and radiographic testing is a non-destructive testing technique for assessing structural integrity, not vapor concentration.