DISTRIBUTED TEMPERATURE SENSING (DTS): PRINCIPLES AND INDUSTRIAL APPLICATIONS
WHY TEMPERATURE MONITORING HAS BECOME A STRATEGIC CHALLENGE
Temperature is one of the most critical physical parameters in industrial operations. Whether in power transmission, pipelines, oil & gas wells, data centers, or civil infrastructure, abnormal temperature variations are often early indicators of failures, inefficiencies, or safety risks.
However, monitoring temperature accurately over long distances remains a major challenge.
Traditional solutions rely on point sensors such as thermocouples or RTDs, which:
- Provide only localized measurements
- Require complex installation and maintenance
- Are difficult to deploy over tens of kilometers
- Often fail to detect early-stage anomalies between sensors
As infrastructures grow longer, more complex, and more critical, operators increasingly need continuous, real-time temperature visibility rather than sparse measurements.
This is where Distributed Temperature Sensing (DTS) has become a key enabling technology.
By transforming a standard optical fiber into a continuous temperature sensor, DTS provides real-time temperature profiles along assets spanning tens of kilometers, with meter-scale resolution and unmatched reliability. Initially developed for oil & gas applications, DTS is now widely used across energy, infrastructure, industrial safety, and environmental monitoring.
WHAT IS DISTRIBUTED TEMPERATURE SENSING (DTS)?
Distributed Temperature Sensing (DTS) is a fiber-optic sensing technology that uses an optical fiber as a fully distributed temperature sensor.
Instead of measuring temperature at discrete points, DTS provides continuous temperature measurements along the entire length of the fiber.
In practice, a single optical fiber can replace thousands of individual temperature sensors, delivering a complete thermal map of an asset or environment.
The fiber itself acts as the sensing element, while a dedicated optoelectronic unit - called a DTS interrogator - analyzes the light backscattered within the fiber to calculate temperature at every point.
THE PHYSICAL PRINCIPLE BEHIND DTS: RAMAN SCATTERING
LIGHT-MATTER INTERACTION IN OPTICAL FIBERS
When a laser pulse travels through an optical fiber, part of the light is scattered backward due to interactions between photons and the molecular structure of the glass. Several scattering mechanisms occur, including Rayleigh, Brillouin, and Raman scattering.
DTS is based on Raman scattering, which is temperature-dependent.
STOKES AND ANTI-STOCKES COMPONENTS
Raman backscattering consists of two key components:
- Stokes signal: weakly dependent on temperature
- Anti-Stokes signal: strongly dependent on temperature
The ratio between the anti-Stokes and Stokes intensities is directly related to the local temperature of the fiber.
By analyzing this ratio as a function of distance—calculated from the time-of-flight of the backscattered light - the DTS interrogator can reconstruct a distributed temperature profile along the fiber.
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ASI and SI signals are measured. This information, together with the calibration constant (an initially known value), enables the determination of the temperature all along the fiber length. |
WHY RAMAN SCATTERING IS IDEAL FOR TEMPERATURE SENSING
Raman-based DTS offers several advantages:
- Direct and absolute temperature measurement
- High stability over time
- Independence from strain
- Excellent accuracy for industrial applications
This makes DTS particularly well suited for long-term temperature monitoring.
HOW A DTS SYSTEM WORKS: STEP BY STEP
A DTS system is composed of three main elements.
THE OPTICAL FIBER
The sensing element is a standard fiber, which can be:
- Embedded in cables
- Attached to pipelines
- Installed in wells
- Buried in the ground
- Deployed in tunnels or industrial facilities
In many deployments, existing fibers - including fibers integrated into cables - can be reused, minimizing installation costs.
The quality of thermal coupling between the fiber and its environment plays a crucial role in measurement accuracy.
THE DTS INTERROGATOR
At FEBUS Optics, the DTS interrogator is called the T1-Pluton. It:
- Emits laser pulses into the fiber
- Measures Raman backscattered signals
- Separates Stokes and anti-Stokes components
- Calculates temperature along the fiber length
- Display real-time data thanks to the included proprietary software FOLog
This all-in-one DTS unit is designed to deliver:
- High temperature accuracy, typically ±1 °C or better
- Long sensing range
- High spatial resolution
- Exceptional measurement stability
An advanced unit such as the T1-Pluton is optimized for industrial environments, combining:
- Easy deployment and configuration
- Swift acquisition launch
- Robust hardware and software
DATA PROCESSING AND VISUALIZATION SOFTWARE
Dedicated software platforms enable operators to:
- Visualize temperature profiles in real time
- Define alarm thresholds and zones
- Detect abnormal thermal patterns
- Integrate temperature data into SCADA or asset management systems
FEBUS’ proprietary FOLog software is designed to be powerful yet easy to operate, reducing training time and operational burden. It thus transforms DTS from a measurement tool into a decision-support system.
KEY CHARACTERISTICS OF DISTRIBUTED TEMPERATURE SENSING
CONTINUOUS TEMPERATURE PROFILES
DTS provides distributed sensing, with temperature measured at every point along the fiber, not interpolated between sensors.
LONG-TERM STABILITY
The DTS T1-Pluton stands out for its measurement stability, with a single calibration performed at the start, ensuring consistent temperature readings over time and making it ideal for long-term monitoring campaigns.
HIGH SPATIAL RESOLUTION
The T1-Pluton offers spatial resolutions range of 1 meter, allowing highly precise localization of thermal anomalies.
PASSIVE AND INTRINSICALLY SAFE TECHNOLOGY
The fiber contains no electrical components and requires no power in the field, making DTS suitable for:
- Hazardous environments
- Remote or hard-to-access areas
- Harsh industrial conditions
WHAT CAN DTS DETECT?
Distributed Temperature Sensing can identify a wide range of thermal events, including:
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These thermal signatures often reveal problems before visible damage or failure occurs.
TYPICAL APPLICATIONS OF DTS
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OIL & GAS, AND GEOTHERMAL WELL MONITORING |
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In well environments, DTS is widely used for:
Because optical fibers withstand high temperature and pressure, DTS is well suited for both temporary and permanent downhole monitoring, especially when integrated into our solution FOWell. |
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STRUCTURAL HEALTH MONITORING (SHM) |
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In dams, galleries, and large industrial sites, DTS provides:
DTS enables:
Combined with our software, the T1 empowers operators with alert notifications and valuable insight to support fast decision-making. |
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PIPELINE INTEGRITY MONITORING |
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In pipelines transporting oil, gas, or chemicals, leaks often create localized temperature anomalies due to fluid expansion, evaporation, or cooling. DTS allows operators to:
FOPipe is our integrated solution leveraging DTS data to enhance pipeline integrity management. |
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CABLE MONITORING |
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In underground, submarine or overhead power cables, temperature is directly linked to:
DTS enables:
FOGrid, the FEBUS cable monitoring solution, provides operators with actionable insights to improve grid reliability and efficiency. |
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DTS KEY TECHNICAL PARAMETERS
BEST PRACTICES AND DEPLOYMENT CONSIDERATIONS
When evaluating a DTS system, several parameters are essential:
- Spatial resolution: distance between measurement points
- Temperature resolution: smallest detectable temperature change
- Sensor configuration: single-ended or dual-ended
To choose the most suitable configuration for each project, FEBUS Optics’ experts bring in-depth expertise in fiber optics as well as strong understanding of application-specific constraints.
Successful DTS deployments depend on:
- Proper fiber selection and installation
- Good thermal coupling between fiber and asset
- Appropriate calibration strategy
- Robust data processing and alarm management
- Integration with operational systemsms
Thus, FEBUS end-to-end solutions combining hardware, software, and application expertise are critical to unlocking the full value of DTS.
WHY DTS RAMAN IS A STRATEGIC TECHNOLOGY
Several global trends are driving the adoption of DTS systems across industries:
- Aging and increasingly complex infrastructure requiring continuous monitoring
- Growing emphasis on safety, risk prevention, and operational reliability
- Expansion of energy networks, including renewables and underground assets
- Stricter environmental, regulatory, and compliance requirements
- Rising demand for real-time, data-driven asset managementorks
DTS directly supports these challenges by delivering continuous, distributed, and reliable temperature monitoring.
FROM TEMPERATURE DATA TO OPERATIONAL INSIGHT
Distributed Temperature Sensing transforms an optical fiber into a powerful, continuous temperature sensor for real-time monitoring of critical assets.
DTS enables operators to detect anomalies early, improve safety, and optimize asset performance, making it a strategic tool for smarter, safer, and more efficient operations.