Fiber Optic Temperature Sensor How It Works

The fibre optic cable can be 30 km in length is passive in.

Fiber optic temperature sensor how it works.

Fiber optic sensors work based on the principle that light from a laser or any superluminescent source is transmitted via an optical fiber experiences changes in its parameters either in the optical fiber or fiber bragg gratings and reaches a detector which measures these changes. Optical fibres an optical fibre consists of a thin low loss glass wire with a centre or core region having a slightly higher refractive index than its surrounding region or cladding. A beam splitter made of glass plate is inclined at an angle 45 0 with respect to the direction of the. It is based on the principle of interference between the beams emerging out from the reference fiber and the fiber kept in the measuring environment.

It depends on the type of sensor. Distributed temperature sensing dts measures temperature distribution over the length of an optical fiber cable using the fiber itself as the sensing element. A fiber optic sensor is a sensor that uses optical fiber either as the sensing element intrinsic sensors or as a means of relaying signals from a remote sensor to the electronics that process the signals extrinsic sensors. Dts systems contain a pulsed laser which sends in an approximately 1m pulse equivalent to a 10ns time into the fibre optic.

As the pulse travels along the length of the fiber optic it interacts with the glass. The temperature measuring system consists of a controller laser source pulse generator for otdr or code generator for code correlation or modulator and hf mixer for ofdr optical module receiver and micro processor unit and a quartz glass fibre as line shaped temperature sensor. It consists of a laser source to emit light. Fiber optic temperature sensor how it works.

Figure 1 schematic of step index optical fibre. This allows a single sensor to both illuminate and view an object through the same fiber optic assembly. Fibers have many uses in remote sensing. If an object appears in front of the sensing end of a bifurcated fiber optic light from one branch will be reflected off the object and back to the receiver through the other branch.

Of optical fibres and each type of sensors. Unlike traditional electrical temperature measurement thermocouples rtd the length of the fiber optic cable is the temperature sensor. They are basically just a regular fiber with a diaphragm on the end that is normal to the fiber. Light is sent to the end of a fiber via a fiber coupler and received by a photodiode phototransistor.