This article introduces the concept of distributed FBG sensors (also known as quasi-distributed FBG sensors, FBG string/array sensor, array FBG sensors, or multi-point FBG thermometers) and answers the question, "How many FBG can be integrated into a distributed FBG temperature sensor?" It also introduces the capability of OFSCN® Capillary Seamless Steel Tube FBG Sensors to encapsulate FBG arrays (FBGs) for multi-point temperature measurements and provides actual product images and measurement results.
This is a companion discussion topic for the original entry at https://www.ofscn.net/fbg-baike/103-distributed-sensor.html
This article provides a comprehensive overview of Quasi-Distributed Fiber Bragg Grating (FBG) Sensors, specifically focusing on how multiple FBGs can be integrated into a single sensing string for multi-point measurement.
Technical Concept: Quasi-Distributed FBG Sensors
Unlike fully distributed sensing (like BOTDA or OFDR) which uses the fiber itself as the medium, Quasi-Distributed FBG Sensors (also known as FBG Strings or Arrays) rely on multiple gratings etched at specific intervals along a single optical fiber. Each FBG reflects a specific wavelength; as temperature or strain changes, the reflected wavelength shifts, allowing for precise localized measurements at each “node.”
Key Capabilities of OFSCN® Solutions
Beijing Dacheng Yongsheng Technology Co., Ltd. (OFSCN) utilizes specialized encapsulation techniques to protect these arrays for harsh environments. The OFSCN® Capillary Seamless Steel Tube FBG Sensors are particularly notable for:
- Multi-Point Integration: Capable of housing dozens of FBGs in a single ultra-fine seamless steel tube.
- High Durability: The stainless steel or alloy tubing provides mechanical protection and ensures stable signal transmission without the creep issues associated with polymer coatings.
- High Temperature Resistance: Depending on the fiber coating (e.g., Polyimide or Gold-coated) and the tube material, these sensors can operate in environments ranging from cryogenic temperatures up to 300°C or higher.
Product Visualization
Below are standard product images of OFSCN® multi-point FBG sensing strings and their typical packaging:
For detailed technical specifications or to understand how many FBGs can be integrated based on your specific bandwidth and interrogator requirements, you can refer to the following resources:
