What model of optical fiber is used for monitoring?

　　There are various models of fiber optics for monitoring, and the specific choice depends on factors such as the occasion of use, transmission distance, and performance requirements. Here are some common fiber optic models for monitoring and their characteristics:

　　Classification by mode of transmission

　　single mode fiber

　　Features: Only one mode of optical signal is transmitted, with a transmission frequency bandwidth, suitable for large-capacity, long-distance optical fiber communication.

　　Transmission distance: up to tens of kilometers.

　　Wavelength of use: usually 1310nm or 1550nm.

　　Common models: G.652, G.653, G.654, G.655, etc.

　　Multimode fiber

　　Features: It can transmit multiple modes of optical signals, with poor transmission performance, narrow frequency band, small transmission capacity, and short distance.

　　Transmission distance: up to 2 kilometers.

　　Wavelength of use: typically 850nm (short wavelength window) or 1310nm (in some cases).

　　Common models: G.651 grade, divided into OM1, OM2, OM3, etc. according to the light mode.

　　Classification according to the occasion of use

　　Indoor fiber optic

　　Features: Suitable for indoor environments, typically with a smaller diameter and higher flexibility.

　　Laying method: commonly used for tight sleeve laying.

　　Outdoor Fiber Optic Cable

　　Features: Suitable for outdoor environments, usually with stronger tensile strength and waterproof performance.

　　Laying method: commonly used as a container for Loose Tube core, including self-bearing overhead optical fiber, pipeline optical fiber, armored buried optical fiber, etc.

　　Branch fiber

　　Features: Suitable for applications that require branching, such as separating multiple branch fibers from the backbone fiber.

　　Distribution fiber

　　Features: used in optical fiber distribution frame or optical fiber end point box, convenient optical fiber connection and management.

　　III. Classification by structure

　　stranded fiber

　　Features: The cable cavity can accommodate multiple loose sleeves, with loose sleeves as the basic unit, each loose sleeve can accommodate 6 to 12 fiber cores. Suitable for optical cables with a large number of cores.

　　Center bundle fiber

　　Features: Built-in contains a central loose tube, which can contain 1 to 12 core fibres. Suitable for optical cables with fewer cores.

　　Ribbon cable

　　Features: Also known as skeleton trough structure, it is usually used as a cable structure with a large number of cores.

　　IV. Other matters needing attention

　　Number of fiber cores: Choose the appropriate number of fiber cores according to actual needs. Generally speaking, the number of fiber cores in each floor wiring room (horizontal wiring cabinet) can be calculated by multiplying the number of switches by 4 plus the redundancy of 4 cores.

　　Optical fiber outer sheath: Choose the appropriate outer sheath material according to the use environment, such as flame retardant, smoke-free, non-toxic, and other types.

　　Laying requirements: The bending radius of the optical fiber should be at least 15 times the outer diameter of the optical fiber to avoid back buckling of the optical fiber. Reserve optical fibers with a length of 5 to 10 meters at both ends and label them for maintenance.

　　In summary, there are a variety of models of fiber optics for monitoring, and the specific selection should be comprehensively considered according to factors such as the occasion of use, transmission distance, and performance requirements. When selecting, it is recommended to consult a professional or refer to relevant standards and specifications to ensure the correct fiber model is selected.