The principle of a fibre optic infrared thermometer
Infrared radiation is the most widespread electromagnetic wave radiation that exists in nature. It is based on the irregular movement of molecules and atoms in any object in a conventional environment, constantly radiating thermal infrared energy. The more intense the movement of molecules and atoms, the greater the radiation energy. Conversely, the smaller the radiation energy. Objects with temperatures above absolute zero will emit infrared radiation due to their molecular motion.
Therefore, by measuring the infrared energy emitted by an object itself, its surface temperature can be accurately determined, which is the objective basis for infrared radiation temperature measurement. Infrared energy is focused on the photoelectric detector and converted into corresponding electrical signals. The signal is converted into the temperature value of the measured target after being calibrated by the amplifier and signal processing circuit according to the internal algorithm and target emissivity of the instrument. Fiber optic infrared thermometer is a device that transmits light through optical fibers to the sensor, rather than being directly focused by a lens onto the sensor. The other principles are the same as ordinary infrared thermometers.
The advantages of fiber optic infrared thermometer
1. Due to the separation of the optical system and circuit system, the optical system of the thermometer can be installed in a high-temperature environment (capable of withstanding 200 degrees Celsius in the field environment) and can work stably online for a long time when applied in industrial sites. Due to the complete absence of electricity in the optical system, the industrial site where it is installed is completely explosion-proof. The circuit part of the thermometer can be installed indoors or away from high temperature sites, connected through optical fibers and optical paths, completely avoiding the interference of high temperature on the instrument's temperature measurement.
2. Due to the fact that the infrared signal of the fiber optic infrared thermometer is transmitted to the sensor through a special material's infrared optical fiber, when the optical path is focused on the optical fiber, only the spot with the size of the fiber optic cross-section can be transmitted to the sensor through the optical fiber. This avoids the impact of large areas of light directly focusing on the sensor and baking it on the stability and lifespan of the sensor. Moreover, infrared optical fibers are made of special materials, allowing only the desired infrared band to be selected through the fiber, further reducing the baking of light on the sensor. Therefore, compared to integrated infrared thermometers, light infrared thermometers have better stability and longer service life.
