What is fiber optic temperature measurement?

Optical fiber temperature measurement technology is a new technology that has only been developed for more than ten years. At present, optical fiber temperature measurement technology is still in the stage of research and development and gradual promotion and practicality. In some occasions where temperature measurement is difficult to solve by traditional methods, it has gradually revealed some of its excellent characteristics. The temperature measurement can be performed on the target objects within the range of strong electromagnetic fields that can cause large measurement errors due to the use of ordinary temperature measuring instruments. Such as high-frequency melting of metal and vulcanization of rubber, temperature measurement in the furnace of microwave heating baking process of wood and fabric, food, medicine, etc. Optical fiber temperature measurement technology has advantages in these fields.

　　The principle of optical fiber temperature sensing is mainly based on the optical time domain reflection principle of the optical fiber and the temperature effect of the back Raman scattering of the optical fiber. When a light pulse enters the fiber from one end of the fiber, the light pulse will propagate along the fiber. Because the inner wall of the optical fiber is similar to a mirror, the light pulse will be reflected at every point in the propagation. There is a small part of the reflected light in the reflection, the direction of which is exactly opposite to the direction of the incident light. The intensity of this back-reflected light has a certain correlation with the temperature of the reflection point in the light. The higher the temperature of the reflection point, the greater the intensity of the reflected light. In other words, the intensity of the back-reflected light can reflect the temperature of the reflection point. Using this phenomenon, if the intensity of the back-reflected light can be measured, the temperature of the reflection point can be calculated. This is the basic principle of measuring temperature using optical fiber.