The online temperature monitoring system for the DTS distributed optical fiber sensor works based on the temperature effect of Raman spectroscopy of optical fiber. It realizes online monitoring and automatic alarm of the cable temperature through the temperature-sensing optical fiber laid on the cable surface, and has the advantages of continuous distributed temperature detection without dead zone, quick and easy installation, excellent dielectric voltage withstand ability, and immunity to electromagnetic interference.

▶ High accuracy, high stability, and high reliability ▶ Intrinsically safe, immunity to electromagnetic interference, strong capability against corrosion, pollution, and lightning, and capable of service under harsh conditions e.g. strong electromagnetic interference, lightning, flammable, and explosive environment,
▶ Measurement distance up to 10Km
▶ Simple system structure, low cost, and long service life

The temperature measurement system consists of the following:
▶ Temperature sensing optical fiber
▶ Multiplexed optical switch
▶ Controller with laser source
▶ Software
▶ Computer

Conventional wiring method
In this scheme, each piece of temperature sensing optical fiber is respectively connected to the corresponding channel of the online temperature monitoring system for 16-channel distributed optical fiber sensor, and the optical fiber is directly laid in parallel to the cables (the cable must be fit close to the temperature sensing optical fiber)

Stepped Wiring Method
In this scheme, a temperature sensing optical fiber is connected to the distributed single-channel online temperature monitoring system for optical fiber sensor. The temperature sensing optical fiber is laid using the form as shown in Fig. (B), and the contact area between the temperature sensing optical fiber and each cable should preferably be in size range of 1M-1.5M to ensure the monitoring accuracy.