FAQs
Why Distributed Temperature Sensors (DTS)
Distributed Temperature Sensing has numerous advantages including the following:
- Fully distributed data greatly increases information and reduces uncertainty
- Sensor is made from standard optical fibre (cost effective)
- Immune to shock/vibration and electromagnetic interference
- No electronics or moving parts in monitoring zones
- Inherently high reliability (sensor design life of >30 years)
- High temperature performance of up to 650°C
- Extremely small for access into space restricted areas (e.g. ducts, oil wells, pipes)
Technology Principle of Distributed Temperature Sensor
The key to understanding Distributed Temperature Sensors is that the optical fibre itself is the sensor and the instrumentation provides measurements at every 1m along the length of the fibre. This means that once the cable is installed the operator is able to receive temperature information at all points along the installation - leaving no areas unmonitored and no room for uncertainty.
For more information on the actual physics behind distributed temperature sensors - please visit the FAQ – What is Distributed Sensing section
Cost Advantages of Distributed Temperature Sensor
The Sensornet Distributed Temperature Sensor uses standard telecoms fibre to make the measurement. There are no special sensors (e.g. Bragg Gratings) embedded in the cable making distributed temperature sensing a very cost effective solution when a large number of measurement points are required.
In addition to the low material cost per sensor, distributed temperature sensing technology also has low system design costs (you do not have to plan the exact location of each sensor), low installation costs and also low maintenance costs (distributed sensing cable has no moving parts and a design life of 30 years). Thus the total cost of ownership of a distributed temperature sensing system is very low.
Typical Applications for Distributed Temperature Sensor
Distributed Temperature Sensing technology shows real advantages over conventional temperature sensing technology when a temperature profile of the installation is required or when a large number of sensing points is crucial. Therefore this technology lends itself to long length applications (pipelines, tunnels, power cables), applications where only small sensors can access (oil wells) and safety critical applications where it is important to have all points monitored (refineries, LNG plants, electrochemical processes). Please refer to our case studies for application examples of distributed temperature sensors.
Safety Advantages of Distributed Temperature Sensor
The Sensornet Distributed Temperature Sensor is ideal for use in hazardous zones and environments where safety is of critical importance. The sensors operate using low optical powers (1mW mean power output) and are not capable of causing ignition thus making them ideal for areas where only intrinsically safe equipment is allowed (e.g. gaseous environments). The Distributed Temperature Ssensor is suitable to monitor Zone 0 Hazardous areas according to the European Commission report no. EUR 16011 EN (1994). Additionally, because optical fibres are not susceptible to electromagnetic interference they are ideal for use in power stations and for monitoring of distribution lines.
The Sensornet Distributed Temperature Sensor has a 1M laser safety classification - meaning that an onsite laser safety supervisor is not required at site of installation.
What is the Longest Range of a Distributed Temperature Sensor?
The Sentinel range of Distributed Temperature Sensors are capable of measuring ranges of up to 60km in distance with a single DTS unit. These means that for a 10km distributed temperature sensing unit you can have up to 10,000 individual measuring points. This ensures full coverage of your assets over extremely long distances.
For more information about our range of Distributed Temperature Sensing products - please visit our product specification page.
What is the Temperature Resolution of a Distributed Temperature Sensor?
The Sentinel range of distributed temperature sensors are capable of measuring temperatures as fine as 0.01°C. For more information of the measurement times need to achieve this resolution - please see the specification sheets for our Distributed Temperature Sensors.
Sensornet Range of Distributed Temperature Sensors
Sensornet offers a range of distributed temperature sensors - ranging from 4km in range to 60km and from a sampling resolution of 50cm. For more information about our range of products - please visit the product specification page
What are the Pressure and Temperature Limitations?
Sensornet have fibres capable of long-term operation at over 650ºC – so there are no practical temperature limits in applications such as oil wells. As optical fibre is simply glass, the practical pressure limits come from the mechanical components e.g. pressure rating of wellhead pass-through, rather than the fibre itself.
What Other Applications can you use DTS for?
Distributed Temperature Sensing is very versatile and potential applications are enormous. Sensornet focuses on four main market segments – Upstream Oil & Gas, Downstream Process, Power, and Hydro. The following list gives you some ideas of other potential applications for distributed sensors:
- Structural monitoring – anything from bridges to aeroplane wings – monitor and understand the movements to achieve more cost-effective designs.
- Linear Heat Detection
- Building Temperature Control
Please contact a Sensornet representative for further information.
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