DTSX1 Fiber Optic Heat Detector

Measurement Principle

Operating Principle

Yokogawa DTSX1 measures temperature and distance over the length of an optical fiber using the Raman scatter principle. A pulse of light (laser pulse) launched into an optical fiber is scattered by fiber glass molecules as it propagates down the fiber and exchanges energy with lattice vibrations. As the light pulse scatters down the fiber optic cable, it produces stokes signal (longer wavelength) and anti-stokes (shorter wavelength) signal, of which both signals shifted from the launch of the light source. The intensity ratio of the two signals components depends on the temperature at the position where the Raman scatter is produced. This temperature can thus be determined by measuring the respective intensities of the stokes and anti-stokes signals. Furthermore, part of the scattered light, known as the backscatter, is guided back towards the light source. The position of the temperature reading can thus be determined by measuring the time taken for the backscatter to return to the source.

Raman Scattering

All light interacts with matter! For example, imagine standing in a pitch black garage with no external light source. Inside this garage is a bright red sports car. Needless to say, you cannot see the sports car or the color of the sports car itself. However, when you turn on the lights to the garage, you can immediately see the light source reflecting the bright red color off the car. The light that is bouncing off the red sports car is only bouncing off the "red" spectrum, therefore, your eyes see the sports car as, well, red.

Types of Scattering Light

Yokogawa's distributed temperature sensors measure temperature distribution using Raman scattering light, which exhibits particularly good temperature sensitivity among the following types of scattering light.

Measurement Method

Single-Ended Measurement Method

• This method launches optical pulses into only one end of the optical fiber for sensing. Easy to install, it is effective when the measuring target is long range.

Double-Ended Measurement Method

• This method launches optical pulses into both ends of a looped optical fiber for sensing.
• This method allows for continued measurement even if on place of the fiber optic cable is broken.

Comparison of Measurement Methods

Types of Temperature Sensors

Types of Temperature Sensors and Their Features

Comparison among Temperature Monitoring Methods

	Fiber Optic Sensor	Thermo Camera	Point Sensor (Thermocouple)
Description	Wide-area monitoring based on a fiber optic sensor	Surface temperature monitoring based on a thermo camera	Multipoint monitoring based on discrete sensors
Detection Method	Contact	Non-contact	Contact
Range of Temperatures Monitored	-200 to 300 °C (Based on a sensor cable)	Normal temperature to 2000 °C (Range switching required)	-200 to 1000 °C (Type K thermocouple)
Area	Coverage of a very wide area DTSX200: up to 6 km / ch DTSX3000: up to 50 km / ch DTSX1: up to 16 km / ch	Small viewing angle of 20°	Wide area
Advantages	Coverage of a very wide area and seamless monitoring	Capability of a limited tiny area monitoring	Capability of a limited tiny area monitoring
Disadvantages	Restricted to small areas	Non-seamless monitoring	Non-seamless monitoring Installation and maintenance of compensating lead wires

Types of cables

You can choose the most suitable type according to your intended use.

Normal Operating Temperature	Applications	Cable Type	Cable Details	Features
Normal Temperature	Conveyor Fire Detection Cable Temperature Monitoring Bus Duct Temperature Monitoring Cable Tunnel Fire Detection Warehouse Fire Detection Hot Spot Detection Cold Spot Detection etc.	Standard Type	Image Zoom	Nonmetal, lightweight, and easy to install EN 54-22 certified
		Robust Type	Image Zoom	Resistant to crush and tension and less likely to break EN 54-22 certified
		Flexible Type	Image Zoom	Thin and flexible and easy to install along the measurement targets
High / Low Temperature	Blast Furnace Monitoring Drying Furnace Monitoring LNG Leak Detection Well Monitoring etc.	Steel Tube Type	Image Zoom	Thin and flexible and easy to install along the measurement targets
		Steel Armored Type	Image Zoom	Resistant to crush and tension and less likely to break

Product Introduction

DTSX1 Overview

The DTSX1, which incorporates a heat detection function in a single box, can be used as a heat detector right away by simply connecting the fiber optic cable supplied as standard. It detects high heat over a wide area quickly and precisely. Also, the ability to configure the alarm display and sound individually to suit your applications enables rapid detection, localization, and identification of abnormalities.

The Advantages of DTSX1:

• Rapid detection of fire over a wide area

  Temperature monitoring up to 16 km length along fiber optic sensor cable with 5 seconds minimum measurement time.
  Very wide area monitoring up to 4 routes (16 km x 4) with optical switch.

• Human error reduction Human dependency prevention

  The continuance monitoring without blind spots doesn't miss abnormal temperature even if hazardous locations or hard-to-reach places.
  Identify abnormal point and allow for quick response with zoning monitor.

• Time and effort reduction for building your system, etc.

  Package system with optic fiber cable and other accessories eliminates the time and effort needed to select them.
  Various host systems can get alarm easily via Modbus/TCP or relay output.

• Running cost and warranty cost reduction

  The fiber optic cable will not break down as it has no mechanical elements, when the cable damages by external force it can replace only damage part.
  Assets insurance cost is reduced by integrating with fire extinguishing system.

On the Partner Portal Member Site, you can check the details of the specifications.
GS 39J06B35-01 : DTSX1 Fiber Optic Heat Detector

Software

DTSX3000 Control Visualization Software (DTAP3000)

Specifications

Refer to the General Specifications for detailed specifications.

DTSX1

REGULATORY COMPLIANCE and CONFORMITY to STANDARDS

Note: Under EU legislation, the manufacturer and the authorised representative in EEA (European Economic Area) are indicated below:
Manufacturer: YOKOGAWA Electric Corporation (2-9-32 Nakacho, Musashino-shi, Tokyo 180-8750, Japan).
Authorised representative in EEA: Yokogawa Europe B.V. (Euroweg 2, 3825 HD Amersfoort, The Netherlands).

Industries/Applicantions

Fire Detection

Early fire detection to critical process and environment is an important component to any safety system. A blazing fire has devastating consequences to important assets, products and most importantly, human lives. Furthermore, the cost of downtime due to fire leads to lost opportunities and costly repairs. Discrete sensor technology often fails due to the surrounding environment conditions such as dust, humidity, heat and corrosion. In addition, it is expensive to maintain a conventional sensor technology due to constant repair. Yokogawa's DTSX1 is designed to detect fire in critical assets under the most extreme conditions and offers unmatched reliability, performance and cost savings.

Yokogawa's DTSX1 is designed to deploy in the following fire detection applications:

• Conveyor belts carrying important goods
• Tank farms
• Cable trays
• Underground tunnels
• Pipelines (underground, above ground)
• Nuclear facilities
• Mining, Refinery

* Assuming appropriate scan rate and data refresh intervals are used

Vehicle Lithium-ion Battery

Smart Monitoring of Manufacturing Process Shelves and Storage Shelves

Thermal runaway of lithium-ion batteries mounted on individual shelves is discovered at an early stage. This enables a quick initial response when an abnormality occurs to limit damage to a minimum.
(For details, refer to "Smart Monitoring of Manufacturing Process Shelves and Storage Shelves -In-vehicle Lithium-ion Battery Applications- ".)

Prevention of Fires in Exhaust Air Ducts in Battery Assembly Process

Fires or dust explosions in exhaust air ducts for preventing the contamination of aluminum dust in the assembly process of lithium battery batteries are monitored. Abnormalities are not overlooked as ducts extending over long distances in blind areas such as roof space are comprehensively monitored. (For details, refer to “Prevention of Fires in Exhaust Air Ducts in Battery Assembly Process -In-Vehicle Lithium-ion Battery Applications- ".)

Monitoring of Soundness of Power Supply Bus Bar

The joints of the power supply bus bar are monitored.
Abnormalities are not overlooked as fiber optic cable is built into the bus duct and bus bars extending over long distances in blind areas such as roof space are comprehensively monitored.
(For details, refer to "Monitoring of Soundness of Power Supply Bus Bar -In-vehicle Lithium-ion Battery Applications-".)

Fiber Optic Cable Visualizes In-furnace Temperature Distribution

The DTSX fiber optic distributed temperature sensor can monitor temperature distribution every meter along the path of the fiber optic cable.
Thermocouples, etc. are used for heater control as up till now, and by adding DTSX to them, it will be possible to visualize the temperature distribution inside the entire drying furnace.
Resolving heater and other problems by utilizing the result, and passing products through the furnace after setting the in-furnace temperature to the ideal temperature profile result in improved productivity.

When attempts are made to measure multiple points by thermocouples, etc., wiring is complicated, construction costs escalate and periodic maintenance of each individual sensor is required. This is unrealistic when applying it to multiple drying furnaces.
As the DTSX system requires only laying fiber optic cable inside the furnace, both initial and running costs can be reduced.
Moreover, a single DTSX can cover multiple drying furnaces, which improves cost effectiveness.
The DTSX has also been put to use in monitoring the temperature distribution in tunnel furnaces.
(For details, refer to "Fiber Optic Cable Visualizes In-furnace Temperature Distribution".)

Power

Yokogawa DTSX1 can protect the infrastructure of existing power line/cable and reduce cost by monitoring the thermal dynamics of the power transmission and distribution line. By measuring the temperature of the power line, power grid operators can maximize the usable capacity of the power current by avoiding power cable damage and extending the cable life by maintaining optical power current. More importantly, operators can identify hot spots, fire breakout and location of fire along the entire grid. DTSX1 minimizes the potential power grid network outages and streamlines preventative maintenance process. Because of its immunity to electromagnetic interference, DTSX1 is ideal for high voltage, high noise environment. DTSX1 is designed to deploy in the following environments:

• Underground power cables
• Subsea power cables
• Overhead power lines
• Distribution station
• Substations