What Makes The System?

An FBG Sensing System comprises of three discrete sub-systems

SENSOR 

A network of fibre Bragg grating sensors or transducers embedded within or attached to the structure being monitored

INTERROGATOR 

An FBG Interrogator, an optoelectronic unit which illuminates the sensor network and records the optical reflection returned from each FBG sensor

PROCESSOR 

A Processing Unit, often simply a PC, which takes recorded data from the interrogator and performs further data processing, user interfacing, data transmission and storage functions. 

How Does It Work?

Fibre Bragg Grating (FBG) is an optical sensor recorded within the core of a standard, single-mode optical fibre using spatially-varying patterns of intense UV laser light. 

FBG SCIENCE 

The interference of two UV coherent beams gives rise to FBG, which is a periodic variation in the refractive index of the fibre capable of reflecting destructively, a specified range of light wavelengths but retain a particular narrow range of wavelength. The filtered and reflected wavelength carries temperature and strain data that is independently inflected upon the respective FBGs. The shift in wavelength carries temperature and strain data. Therefore when processed, the data turns to useful temperature and strain information. 

FBG MEASUREMENTS

FBG can be used to make temperature measurements by isolating the fibre from strain, and temperature compensated strain measurements can be made with knowledge of the temperature, often conveniently derived from a second, strain-isolated FBG.

What Interrogates?

There are many types to how an FBG can be interrogated. This can be achieved by using either a broadband light source and a spectrometer for detection, or an agile tunable or swept-wavelength light source and photodiode detectors. 

The Fibervis Solution

BEST PRICE TO PERFORMANCE RATIO

VisFBG is a revolutionary optical sensor embedded within a standard optical fibre. It reflects light over a narrow bandwidth, responding faithfully to temperature and strain changes. In one optical fibre, multiple FBG sensors can be inscribed and interrogated simultaneously using a single instrument. The result is a very low-cost distribution monitoring mechanism for strain and/or temperature within large structures, which is particularly useful for assessing structural health and validating design parameters. 

While it is important to define an appropriate FBG, it is also important to achieve the best interrogator price to performance ratio for the type of application it is intended for. High acquisition rates at long range/distances and with multiple FBGs capable of being interrogated simultaneously defines the performance of an interrogator. High performance interrogators however may be expensive and may be overengineered for the application that it is intended for. 

Here at FIBERVIS, we provide FBG and interrogator solutions in tandem to the type of application that is requested of. Do consult us for further information.