FAA Powerplant Written Practice Test

Optical fire detection systems can utilize which types of light?

1. Infrared or ultraviolet

2. Visible or infrared

3. Ultraviolet or fluorescent

4. Visible or ultraviolet

The correct answer is: Infrared or ultraviolet

Optical fire detection systems are designed to identify fire or combustion by detecting specific wavelengths of light that are emitted during a fire. These systems can utilize infrared and ultraviolet light for effective fire detection. Infrared light is associated with the heat produced by flames and can be used to detect the thermal radiation emitted from a fire. Unlike visible light, which requires a certain level of illumination, infrared detection is effective even in darkness and can sense heat signatures in various conditions. Ultraviolet light, on the other hand, is emitted by flames, particularly in the early stages of combustion. It is sensitive to specific wavelengths that occur with certain types of fire, making it a useful component for early fire detection. The combination of these two types of light enables the system to reliably detect a wider range of fire types and conditions, ensuring quicker response times and enhancing safety. Other options tend to include light types that are not specifically used or effective for fire detection, making them less suitable compared to the infrared and ultraviolet combination.