The main feature of Fiber Optic Pyrometer is that it has a temperature measuring probe with an optical fiber. The length of the optical fiber ranges from several meters to hundreds of meters, collectively referred to as optical fiber temperature sensors. According to the role of optical fiber in the sensor, it is divided into two categories: functional type and non-functional type.

(1) Functional Fiber Optic Pyrometer. Also known as all-fiber type or sensor type Fiber Optic Pyrometer. Its characteristics are: the optical fiber is not only a temperature sensing element, but also a light guide. This Fiber Optic Pyrometer has excellent performance and complex structure, making it difficult to manufacture.

(2) Non-functional Fiber Optic Pyrometer. Also known as the light-transmitting Fiber Optic Pyrometer. Its characteristics are: the temperature sensing function is completed by non-fiber-type sensitive components, and the optical fiber only plays the role of light guide. This Fiber Optic Pyrometer has stable performance, simple structure and easy realization. At present, most practical Fiber Optic Pyrometers are of this type, and the optical fibers used are mostly multimode quartz optical fibers.

According to different usage methods, Fiber Optic Pyrometer can be divided into:
(1) Contact Fiber Optic Pyrometer. When in use, the optical fiber temperature sensor is in contact with the object to be measured. Such as fluorescence Fiber Optic Pyrometer, semiconductor absorption fiber optic thermometer and so on.

(2) Non-contact Fiber Optic Pyrometer. When in use, the optical fiber temperature sensor does not contact the object to be measured, but uses the principle of thermal radiation to sense temperature, and the thermal radiation on the surface of the object to be measured is received and transmitted by the optical fiber, so it is also called the optical fiber radiation Pyrometer.