Innovation: Optical fibre hot tip for industrial safety

AFTER its successful role in the telecommunications revolution, optical fibre is poised to cut costs and improve safety in other industries, such as power transmission and petrochemicals, which rely on temperature sensing to ensure the safe and efficient operation of factories and equipment.

The technique works by sending a laser pulse of light down an optical fibre and measuring changes in its properties when it is reflected back. Variations in the reflected light translate into temperature readings, while the time between injecting the pulse and receiving the reflected signal pinpoints the location of the temperature reading.

Traditional temperature sensing relies on discrete sensors, such as thermocouples, which provide information only from their own location. They must be linked to a data acquisition unit, which often causes complex wiring problems.

When there is a need for multiple-point or shifting monitoring, discrete sensors are inflexible and expensive. Optical fibre sensors can discriminate between temperature readings only a metre apart for distances of up to 40km - long enough to reach across the English Channel.

Users can monitor thousands of points without needing to decide where to take the measurements.

Adopting optical fibre to monitor temperatures is the work of York Sensors, a Southampton company with close links to Southampton University, which has pioneered many developments in optical fibres. Peter Orrell, sales and marketing manager of York Sensors, says it might cost around pounds 10 per point to install discrete sensors, whereas an optical fibre system costing pounds 50,000 could measure up to 10,000 points.

'Not only can an optical fibre system provide information from thousands of points, it can respond to temperature changes in less than a second and continues to measure even if the fibre is broken,' Mr Orrell says.

This makes the technique very powerful in fire detection. It also has an advantage over infra-red fire detection systems, which cannot distinguish between smoke and fire, in being able to pinpoint the seat of a fire.

York Sensors is working with companies to develop new applications. In the chemical industry, the method is being used for surface monitoring of vessels that operate under high temperature and pressure. Such vessels have refractory linings that can fail. By winding the optical fibre on to the outside of the vessel, any hot spots, indicating lining failure, can be detected.

Mr Orrell says companies using the technology do not want to be named, as they believe the ability it gives them to operate safely with fewer maintenance shutdowns provides an advantage over competitors.

Optical fibre is flexible and easy to install, and is now so cheap (a few pence per metre) that it can economically be used to monitor long lengths of pipeline.

The fibre can be sheathed in different coatings, allowing it to operate at temperatures between minus 190C and 460C.

One low-temperature application, being tested by Gaz de France, is monitoring gas pipelines. Gas is moved as a liquid at low temperatures. Any leak - which could cause an explosion - is registered as a cold spot.

Oil pipelines could also be monitored to ensure that the water in unrefined oil did not freeze, blocking the pipeline.

'Because the fibre does not depend on electrical current to transmit its measurements, it is an ideal monitoring technique for oil pipelines and refineries, where electric sparks can cause explosions,' Mr Orrell explains.

The National Grid, in collaboration with Electricite de France, is currently assessing the sensors for monitoring underground cables, which must operate below a certain temperature to avoid burn-out.

National Grid has 600 route kilometres of underground cable and its safe capacity varies, depending on the time of the year and ambient temperature.

The difficulty of monitoring underground cables has led electricity companies to specify a higher capacity than they need (at a significantly higher cost). According to Mr Orrell, York Sensors has now given electricity companies the confidence to specify lower-capacity cables.

News
The surrealist comedian at the Q Awards in 2010
people
News
Russell Brand arriving for the book launch in East London
peopleRussell Brand cancels his book launch debate due to concerns about the make-up of the panel
Sport
Christiano Ronaldo enjoys his opening goal
champions leagueLiverpool 0 Real Madrid 3: Ronaldo and Benzema run Reds ragged to avenge thrashing from their last visit to Anfield
Arts and Entertainment
Awesome foursome: Sam Smith shows off his awards
music22-year-old confirms he is 2014’s breakout British music success
PROMOTED VIDEO
Life and Style
Six of the 76 Goats' cheese samples contained a significant amount of sheep's cheese
food + drink
Arts and Entertainment
Contestants during this summer's Celebrity Big Brother grand finale
tvBroadcaster attempts to change its image following sale to American media group
Extras
indybest
Arts and Entertainment
Sir Nicholas Serota has been a feature in the Power 100 top ten since its 2002 launch
art
Arts and Entertainment
Sarah Dales attempts to sell British Breeze in the luxury scent task
tvReview: 'Apprentice' candidate on the verge of tears as they were ejected from the boardroom
News
Call me Superman: one of many unusual names chosen by Chinese students
newsChinese state TV offers advice for citizens picking a Western moniker
News
ebooksAn unforgettable anthology of contemporary reportage
News
Wilko Johnson is currently on his farewell tour
people
Voices
New look: Zellweger at Elle's Women in Hollywood awards on Monday
voicesRenée Zellweger's real crime has been to age in an industry that prizes women's youth over humanity, says Amanda Hess
News
Let’s pretend: KidZania in Tokyo
educationKidZania lets children try their hands at being a firefighter, doctor or factory worker for the day
Life and Style
CHARGE BOOSTER: Aeroplane mode doesn't sound very exciting, but it can be a (phone) hacker's friend. Turning on the option while charging your mobile will increase the speed at which your phone battery charges
techNew book reveals how to rid your inbox of spam, protect your passwords and amplify your iPhone
Arts and Entertainment
Julianne Moore and Ellen Page are starring together in civil rights drama Freeheld
film
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs Money & Business

IT Systems Business Analyst - Watford - £28k + bonus + benefits

£24000 - £28000 per annum + bonus & benefits: Ashdown Group: IT Business Syste...

Trainee Recruitment Consultant - Birmingham - Real Staffing

£18000 - £23000 per annum + Commission: SThree: The SThree group is a world le...

Trainee Recruitment Consultant Birmingham

£18000 - £23000 per annum + Comission: SThree: The SThree group is a world lea...

Trainee Recruitment Consultants

£20000 - £25000 per annum + OTE £Competitive: SThree: SThree Group and have be...

Day In a Page

How could three tourists have been battered within an inch of their lives by a burglar in a plush London hotel?

A crime that reveals London's dark heart

How could three tourists have been battered within an inch of their lives by a burglar in a plush London hotel?
Meet 'Porridge' and 'Vampire': Chinese state TV is offering advice for citizens picking a Western moniker

Lost in translation: Western monikers

Chinese state TV is offering advice for citizens picking a Western moniker. Simon Usborne, who met a 'Porridge' and a 'Vampire' while in China, can see the problem
Handy hacks that make life easier: New book reveals how to rid your inbox of spam, protect your passwords and amplify your iPhone

Handy hacks that make life easier

New book reveals how to rid your email inbox of spam, protect your passwords and amplify your iPhone with a loo-roll
KidZania lets children try their hands at being a firefighter, doctor or factory worker for the day

KidZania: It's a small world

The new 'educational entertainment experience' in London's Shepherd's Bush will allow children to try out the jobs that are usually undertaken by adults, including firefighter, doctor or factory worker
Renée Zellweger's real crime has been to age in an industry that prizes women's youth over humanity

'Renée Zellweger's real crime was to age'

The actress's altered appearance raised eyebrows at Elle's Women in Hollywood awards on Monday
From Cinderella to The Jungle Book, Disney plans live-action remakes of animated classics

Disney plans live-action remakes of animated classics

From Cinderella to The Jungle Book, Patrick Grafton-Green wonders if they can ever recapture the old magic
Thousands of teenagers to visit battlefields of the First World War in new Government scheme

Pupils to visit First World War battlefields

A new Government scheme aims to bring the the horrors of the conflict to life over the next five years
The 10 best smartphone accessories

Make the most of your mobile: 10 best smartphone accessories

Try these add-ons for everything from secret charging to making sure you never lose your keys again
Mario Balotelli substituted at half-time against Real Madrid: Was this shirt swapping the real reason?

Liverpool v Real Madrid

Mario Balotelli substituted at half-time. Was shirt swapping the real reason?
West Indies tour of India: Hurricane set to sweep Windies into the shadows

Hurricane set to sweep Windies into the shadows

Decision to pull out of India tour leaves the WICB fighting for its existence with an off-field storm building
Indiana serial killer? Man arrested for murdering teenage prostitute confesses to six other murders - and police fear there could be many more

A new American serial killer?

Police fear man arrested for murder of teen prostitute could be responsible for killing spree dating back 20 years
Sweetie, the fake 10-year-old girl designed to catch online predators, claims her first scalp

Sting to trap paedophiles may not carry weight in UK courts

Computer image of ‘Sweetie’ represented entrapment, experts say
Fukushima nuclear crisis: Evacuees still stuck in cramped emergency housing three years on - and may never return home

Return to Fukushima – a land they will never call home again

Evacuees still stuck in cramped emergency housing three years on from nuclear disaster
Wildlife Photographer of the Year: Intimate image of resting lions claims top prize

Wildlife Photographer of the Year

Intimate image of resting lions claims top prize
Online petitions: Sign here to change the world

Want to change the world? Just sign here

The proliferation of online petitions allows us to register our protests at the touch of a button. But do they change anything?