Distributed Temperature Sensing (DTS) Interrogator

Continuous temperature profiling over the entire fibre length

The Distributed Temperature Sensing (DTS) interrogator is a fully distributed fibre-optic instrument that continuously resolves temperature along the entire length of a standard telecommunications-grade optical fibre. By eliminating the need for discrete point sensors, the system provides a cost-effective and intrinsically robust solution for continuous temperature profiling in downhole, pipeline, conveyor, data centre and other temperature-sensitive area monitoring applications.

01Manta - DTS interrogator, 19" rack-mount chassis.

Specification

Raman backscattering with optical time-domain reflectometry

The DTS interrogator exploits optical time-domain reflectometry (OTDR) in conjunction with the spontaneous Raman backscattering effect that occurs when a pulsed laser propagates through an optical fibre. As the pulse travels along the fibre, a fraction of the incident light is backscattered at every point along its path.

The intensity ratio between the Stokes and anti-Stokes components of the backscattered Raman signal is intrinsically temperature-dependent and constitutes the physical basis of the temperature demodulation. By simultaneously analyzing the round-trip transit time of the backscattered light, the interrogator locates the corresponding scattering point along the fibre with high spatial precision, thereby delivering a continuous temperature profile over the entire sensing length from a single measurement.

Key features

• Fully distributed temperature sensing along the entire fibre length, without discrete sensing elements
• Passive, all-dielectric sensing fibre, intrinsically immune to electromagnetic interference
• In addition to the standard single-ended configuration, the DTS interrogator supports a double-ended measurement mode, offering several advantages over single-ended operation:
  • Automatic differential loss compensation — by combining traces acquired from both fibre ends, the system compensates for localised attenuation events
  • Improved temperature accuracy over the full sensing length — double-ended averaging corrects the gradual accuracy roll-off that single-ended systems exhibit toward the far end of the fibre
  • Built-in fibre integrity verification — continuous acquisition from both directions allows a fibre break or excess-loss event to be identified and localised in near real time, rather than being discovered only as a loss of far-end data
• Wide operating temperature range, extending to 700 °C with specialty high-temperature gold coated fibre
• Configurable channel count (1–12 channels) supporting simultaneous multi-well or multi-zone deployment from a single interrogator
• Long-range sensing capability of up to 50 km per channel
• Flexible communication interfaces (RS232/485, Ethernet, USB) for integration with SCADA and data-acquisition platforms

Typical applications

• Downhole temperature monitoring — real-time monitoring and interpretation of production profiles in oil and gas wells
• Wellbore integrity monitoring
• Thermal recovery operations — temperature-profile monitoring during SAGD, steam stimulation/throughput, hydraulic fracturing, and gas lift
• Fluid behaviour characterisation during production or water/steam injection, supporting enhanced oil recovery and reduced operating cost
• Pipeline monitoring — leak detection, hot/cold-spot identification, and third-party-intrusion detection along the pipeline route
• Conveyor belt monitoring in mining and bulk-material handling, for early detection of belt friction, idler-bearing overheating, and fire precursors
• Data centre monitoring — under-floor and hot-aisle/cold-aisle temperature profiling, and continuous thermal surveillance of high-ampacity bus ducts and cable trays
• Warehouse and large-facility fire early-warning — continuous temperature profiling across storage racks and open floor areas where discrete point sensors would leave coverage gaps
• Cable tunnels, cable galleries, and underground utility corridors — continuous thermal monitoring of power cables and identification of localised hot spots caused by overloading or poor jointing
• Other temperature-sensitive linear or distributed assets — tank farms, conveyor and process piping in industrial plants, and building/structural fire detection