Distributed sensing is a technology that utilizes an entire fiber optic cable as sensor to conduct measurements in real time .

Distributed sensing takes the advantage of utilizing optical fiber itself as a sensing element and does not rely upon individual sensors at each pre-determined measurement point.

The optical fiber is connected to an interrogator that sends a series of pulses into the fiber. The time of the return of reflected signals is then recorded and analyzed. As optical fibers are made of glass, it is naturally highly durable and cost-effective, making them the ideal sensor to be deployed even in the harshest and most unusual environments.

In AK-Sens, we use distributed sensing in acquiring acoustic (vibration/sound) and temperature data.

Working principle: The interrogator continuously emits light pulses into the optical fiber. As the light pulse transmits along the fiber, reflected light signals are generated along all passing positions. The reflected light signals contain the acoustic wave/temperature information of the corresponding reflection point. After recording the reflecting optical signal, the acoustic wave/temperature information of all points along the sensing fiber can be analyzed.

Positioning ability: Based on the principle of optical time domain reflection (OTDR, similar to the principle of radar), the time difference between the received optical signal and the incident light pulse can be used to calculate the corresponding position of the acoustic wave/temperature information, and perform precise positioning on the entire sensing fiber.