4 Fibre Optic Sensing Applications you should know
4 Fibre Optic Sensing Applications you should know
Fibre optic sensing is a technology which has been around for many years but over the last decade has been adopted in an ever increasing number of environments & applications. A number of differing methods are used to gather the data by using the transmission, reflection & scattering properties of fibre as it reacts to local forces. (eg: Rayleigh, Raman & Brillouin scattering)
Each method is chosen to best serve an application based on the distance, accuracy/resolution, and speed of measurement required. The light is often required to travel long distances, or is very weak upon its return so many systems also require special stages of amplifiers.
Other enabling developments have been the advances in the actual cable and attachment technology to ensure when the fibre is being laid, attached or embedded it only senses the required element it is looking for. This also leads to high reliability and low maintenance of the sensing system.
Application for Acoustic sensing:
Acoustic sensing is a technology used to monitor all sort of sensitive locations, from oil & gas pipelines to railway tracks, military bases and international borders. Recently we have also seen that this technology serves for fracking. This system deploys fibre optic underground and uses sharp pulses of laser light, usually of a narrow band and low phase noise.

When sounds from above are transmitted through the ground, they cause minuscule vibrations in the cable, and so can be sensed. This is also used for detecting leaks in off shore pipelines, as fibres sense the changing of acoustic pitch of the surrounding water. Acoustic sensing can also be used to determine the presence of gas bubbles in oil pipes, which in turn can be interpolated into flow data.
Application for Temperature sensing:
Measuring temperature; this is a similar idea to the acoustic sensing. A system pulses laser light through a fibre optic cable and detects the amount and type of light reflected back to the unit. By using sophisticated algorithms, this light backscatter is translated into temperature data. Systems can detect change in temperature of less than 0.01°C and pinpoint the location of a thermal event to within one metre. This system is widely used in oil & gas industries to monitor in real time down hole temperatures, long pipelines for leaks. The very low power and optical nature of the sensing makes this ideal for use with hazardous flammable materials or harsh environments such as deserts or arctic conditions.
Application for Strain & Pressure sensing:
A distributed strain system can accurately locate ground movements near pipelines such as landslides, erosion or seismic activity with a resolution of 20 microstrain at 1metre intervals over many kilometres. Strain sensing is also used to monitor underground tunnels or in cities to monitor local structures while major close-by excavations might be undertaken. Monitoring can be done continuously with one interrogator looking at many channels by using a combination of circulators & switches or routinely as part of regular inspections.
Application for Intruder detection:
Fibre sensing systems can pick up tiny vibrations and combine some of the sensing methods described above. They can be constructed into a range of intruder detection applications. A fibre can be imbedded into a fence, pipeline or trench and linked to a system which can detect and identify locations of disturbances.

AMS Technologies:
AMS Technologies are a leading supplier and working partner to many of the industry leaders of fibre optic sensing. From component parts such as light sources, switching, splitting, amplifying and detection, through to specialised sub-assembly systems to aid timely production schedules. We have many years of industry knowledge, so please call 01455 556360 or mail, info@amstechnologies.com to discuss your application.
Download our PDF brochure: "Solutions for discrete and distributed mechanical and temperature sensors"

AMS Technologies gives a short overview about components, modules and instrumentation for discrete and distributed sensors covering distances from few meters up to 100 km or more.