NCIDQ IDFX Practice Exam

What type of radiation does a flame detector respond to?

1. Ultraviolet and infrared radiation

2. X-ray radiation

3. Visible light

4. Gamma radiation

The correct answer is: Ultraviolet and infrared radiation

A flame detector primarily responds to ultraviolet and infrared radiation. This type of detector is designed to sense the distinct wavelengths of light emitted during combustion processes. The presence of a flame generates both ultraviolet light due to the ionization of gases and infrared radiation from the thermal energy produced. Ultraviolet radiation is particularly useful for detecting flames as it has specific characteristics that correlate with high-temperature combustion. Infrared radiation can detect the heat signature of a flame, which is crucial for early warning systems in environments where safety is a priority. By responding to these two specific ranges of radiation, flame detectors can provide accurate and timely alerts to the presence of fire, ensuring effective safety measures are put in place. The other types of radiation mentioned, such as X-ray, visible light, and gamma radiation, do not typically play a role in the functioning of flame detectors. X-rays and gamma rays are associated with nuclear reactions and certain types of high-energy processes, while visible light may not provide the distinct signatures needed to reliably identify the presence of a flame. Thus, the correct response is that flame detectors effectively sense ultraviolet and infrared radiation.