The flame ionization detector (FID) is a well-known device that is used in gas chromatography to measure the concentration of organic compounds in a gas sample. However, there are several other terms used to describe this type of detector in various industries. For example, in the environmental monitoring field, FID is referred to as a photoionization detector (PID). In agriculture, it is called a thermal conductivity detector (TCD). In the petrochemical industry, it is often referred to as a hydrocarbon analyzer or flame photometric detector (FPD). Despite the different names, the fundamental principle behind these detectors remains the same: to detect and measure the presence of a specific gas in a sample.