VIAVI is the sole provider of portable distributed temperature and strain sensing (DTSS) and distributed temperature sensing (DTS) solutions that include OTDR test functionalities. This unique combination allows users to validate the optical fibre sensor before conducting temperature and strain measurements.
The VIAVI solution, based on Brillouin-OTDR and Raman-OTDR technologies, are versatile and can be used on battery-powered field platforms or rack-mounted for automated fibre monitoring applications, providing flexibility for different operational needs.
Fibre optic sensing is an advanced technology that harnesses the physical properties of light as it travels along an optical fibre to detect changes in temperature, strain, and other environmental parameters. This innovative approach utilises the fibre itself as the sensor, creating thousands of continuous sensor points along its length. This technique is known as distributed fibre optic sensing, offering a level of detail and coverage that traditional point sensors cannot match.
The devices used to measure the fibre itself are generally called interrogators. These sophisticated instruments are designed to use either standard telecommunications fibre or specially designed fibre for measuring temperature and strain along its entire length. This is achieved using advanced Raman and Brillouin Distributed Fibre Sensor techniques, which we'll explore in more detail later.
The applications of fibre optic sensing are vast and varied. For instance, by using a fibre sensing interrogator, one can:
Below are examples of fiber sensing applications:
Fibre optic sensing can be categorised into two main types: extrinsic and intrinsic sensing. Extrinsic sensing uses a fibre optic cable as a communication path between a test station and an external sensor. However, intrinsic fibre sensing, which is the focus of distributed temperature sensing systems (DTS) and DTSS, utilises the fibre itself as the fibre optic sensing system.
The primary advantage of intrinsic fibre sensing technology is that it eliminates the need for discrete interfaces between the fibre and external sensors. This reduction in complexity translates to lower costs and increased reliability. To make this possible, external stimuli such as temperature fluctuations and strain need to influence the light source within the cable in a measurable and predictable way, providing useful data for analysis.
The science behind fibre sensing relies on several scattering phenomena:
Distributed fibre optic sensing (DFS) effectively utilises both Raman and Brillouin scattering phenomena. Raman scattering is primarily used for Distributed Temperature Sensing (DTS), while Brillouin scattering is employed in Distributed Temperature and Strain Sensing (DTSS). A key advantage of these measurements is that they are not influenced by the optical loss of the fibre, allowing for accurate monitoring of temperature and strain over tens of kilometres.
In this context, the term "distributed" refers to fibre sensing technology that can measure continuously throughout the complete length of the fibre. Essentially, the fibre itself becomes the sensor, offering a level of coverage and detail that point sensors simply cannot match. Since these fibre sensing methods are completely intrinsic, standard telecommunications fibre can often be used as the sensing medium, provided the temperature remains below 100°C (212°F) and the fibre is not subjected to excessive chemical or mechanical disruption.
Distributed fibre optic sensing, including DTS and DTSS technologies, has a wide range of applications across various industries. Here are some key areas where these innovative technologies are making a significant impact:
These applications demonstrate the versatility and importance of distributed fibre optic sensing technologies in modern industry and infrastructure management. As the technology continues to advance, we can expect to see even more innovative applications emerge, further cementing the role of DTS and DTSS systems in ensuring safety, efficiency, and reliability across a wide range of sectors.
Fibre optic sensing technology has revolutionised the way we monitor and protect critical infrastructure and networks. By leveraging the unique properties of optical fibres, we can now detect and locate issues with unprecedented accuracy and speed. This technology is particularly useful in various applications, including optical network sensing and infrastructure monitoring.
Several infrastructure monitoring applications are available with VIAVI fibre sensing interrogators, each designed to address specific challenges in different sectors:
VIAVI, a leader in fibre optic sensing technology, offers a comprehensive portfolio of sensing interrogators designed to meet various monitoring needs. The VIAVI fibre sensing portfolio includes:
These cutting-edge technologies offer unparalleled capabilities in infrastructure monitoring and protection, providing real-time, continuous data along the entire length of the fibre optic cable.
Periodic infrastructure inspection is crucial for maintaining the integrity and safety of critical systems. VIAVI offers two primary approaches to conducting these inspections:
Below is an example of how the VIAVI DTSS works:
This sophisticated technology allows for precise measurement of both temperature and strain, making it invaluable for a wide range of monitoring applications.
Below is an example of the VIAVI DTSS:
Fiber monitoring systems play a crucial role in reducing Mean Time To Repair (MTTR) for critical infrastructure and fibre networks. Here's how:
For instance, a DTSS strain test might show three strain peaks, indicating areas where the fibre is compromised. A classic Rayleigh OTDR might not reveal this problem, but the DTSS data clearly shows that the fibre needs replacement in these areas.
By providing immediate alerts, precise location information, and comprehensive damage assessment, fibre testing significantly reduces the time required to identify and repair issues in critical infrastructure and fibre networks. This not only minimises downtime but also helps prevent more serious failures by identifying potential problems before they escalate.
To learn more about our fibre testing solutions and how they can help protect your critical infrastructure, get in touch with our team.
VIAVI design and manufacture communications test and measurement equipment (optical communications components, modules, and subsystems) as part of their broader portfolio of instruments, systems, and software for network operators.
In an effort to be more responsive to the industry, in 2015 JDSU has separated itself into two independent companies, VIAVI and Lumentum Holdings Inc., each with their own focus:
You can learn more about the changes on the new VIAVI website - and don't hesitate to contact the AusOptic team for more information.