DTSX200 Distributed Temperature Sensor

The DTSX200 adapts flexibly to the installation environment as a standard model. Using data obtained from temperature distribution measurement, we contribute to monitoring of plant facilities, maintenance and management of the integrity of high-temperature furnaces, and prevention of failures.


  • Conveyor Belt Fire Detection
  • Duct Fire Detection
  • Power Cable Monitoring for Overheating
  • Bus Bar Monitoring for Overheating
  • Pipeline Leak Detection
  • Furnace Monitoring for Safety and CBM
  • Maximizing VSD Efficiency

What Is Distributed Temperature Sensing?

Distributed temperature sensing (DTS) measures temperature distribution over the length of an optical fiber cable using the fiber itself as the sensing element. Unlike traditional electrical temperature measurement (thermocouples & RTD), the length of the fiber optic cable is the temperature sensor. Distributed temperature sensing can provide thousands of accurate and precise temperature measurements over a long distance. Compared to traditional electrical temperature measurements, distributed temperature sensing represent a cost effective method for obtaining accurate and high resolution temperature measurement.


System Configuration Example

DTSX3000 / DTSX200 System Configuration Example


How Does It Work?

DTSX200 6km

Yokogawa DTSX200 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.


What Is Raman Scatter Principle?

What is Raman Scatter Principle

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.

This phenomena is also true when you shoot a pulse of light (laser pulse) off of a molecule, in this case, the fiber glass molecule in the optical fiber cable. When the light source enters the optical fiber cable, most of the light bounces (backscatter) back unchanged (no change in wavelength). However, a small amount of that light shifted/changed. That shift/change from the light source is called Raman Scatter. Since Raman Scatter is thermally influenced by temperature, the intensity depends on temperature. Distributed temperature sensing is capturing the shift/change from the propagating light pulse and measuring the intensities between the two signal components (stokes and anti-stokes).


What Are The Advantages of Using DTS?

  1. Cost! When an application requires hundreds or thousands of sensors to be measured, it becomes very expensive to wire each individual sensor back to a data acquisition station. It is much more cost effective and beneficial to acquire accurate and high resolution temperature measurement using fiber optic cable.
  2. Long distance! It is difficult to measure temperature over a long distance using traditional electrical measurement sensors. Not only can DTS fiber optic cable be deployed over a long distance but it also provides a high resolution profile of the area as well as accurate and precise temperature measurement over that distance.
  3. High electromagnetic noise environment! DTS is isolated from electromagnetic noise because of its optical characteristics. Unlike traditional electrical measurement sensors (thermocouple & RTD) there is no electrical component within the optical fiber, therefore, it is immune to electromagnetic noise.
  4. No knowledge of sensor placement! It is not always possible to identify the correct location to deploy temperature sensors ahead of time. Because of the high spatial resolution along with long distance capability of DTS, engineers can deploy multiple optical fiber along the same area to ensure precise and accurate temperature.



DTSX200 Specifications

Refer to the General Specifications for detailed specifications.

Items Specifications
Distributed temperature measurements Distance Measurement distance range 1 km, 2 km, 3 km, 4 km, 6 km
Sampling resolution 10 cm, 20 cm, 50 cm, 1 m
Spatial resolution 1 m (10 to 90 %)
Temperature Measurement temperature range -200 to +300 °C
Temperature resolution Range
Time 1 km 3 km 6 km
10 sec 0.5 1.1 4.2 °C
1 min 0.3 0.6 2.1
10 min 0.1 0.2 0.7
(1sigma, without optical switch)
Sensor optical fiber Optical fiber 50 / 125 μm GI
(No reflection at end of optical fiber)
Optical connector E2000 / APC
Interface Serial
  3 ports, non-isolated, RJ45 modular jacks
Full duplex, asychronous
SERIAL 1 Function: Communication (Modbus)
Baud Rate: 1.2, 2.4, 4.8, 9.6, 19.2, 38.4, 57.6, 115.2 kbps
SERIAL 2 Function:,Communication (Modbus)
Baud Rate: 1.2, 2.4, 4.8, 9.6, 19.2, 38.4
SERIAL 3 Function: Maintenance (Private)
Ethernet Interface LAN 1 port, 10 BASE-T or 10 BASE-TX,
RJ45 modular jacks, automatic negotiation,
automatic MDI, with Network power switch
Power Supply Consumption Operating Mode 10 W
Power save mode 2.1 W
Dimensions (W x H x D) 197.8 x 132.0 x 162.2 mm (6 slots width)
Weight 2.5 kg

Temperature calibration of the Sensor Optical Fiber for DTSX200 is required before temperature distribution measurement.


Item Specifications
Insertion loss 0.6 dB (Typical)
1.4 dB (Max.)
1.0 dB (Typical)
3.0 dB (Max.)
0.8 db (Typical)
1.4 dB (Max.)
Distributed temperature measurements Measurement Single end, Double end
Sensor optical fibers Optical fiber 50/125 μm GI closed end, non refraction required
Optical connector E2000/APC
Optical channels 2 channels 4 channels 16 channels
Interface Control Controlled by DTSX200
Display LEDs: HRDY, RDY, Alarm, Active channel
Power supply Consumption 1 W 1 W Operating 4.5 W
Power save 1 W
Dimensions (W x H x D) 65.8 x 130.0 x 160.3 mm
(2 slots width)
65.8 x 130.0 x 160.3 mm
(2 slots width)
65.8 x 130.0 x 160.3 mm
(2 slots width)
Weight 0.6 kg 0.64 kg  

Note:  As a guideline, the module should be replaced periodically every 4.7, 6, and 9.5 years for continuous operation of 15-second, 20-second and 30-second measurements, respectively.

Compliant Standards

Item Specifications
(✓: Compliant)
Suffix Code
0: Standard 9: EAC
Safety Standards CSA C22.2 No. 61010-1-04  
EN 61010-1:2010  
EN 61010-2:2010  
CU TR 004  
EMC Standards CE Marking EN 55011: 2009 +A1:2010 Class A Group 1
EN 61000-6-2:2005
EN 61000-3-2:2006 +A1:2009 + A2:2009
EN 61000-3-3:2008
RCM EN 55011:2009 +A1:2010 Class A Group 1  
KC Marking Korea Electromagnetic Conformity Standard  
EAC Marking CU TR 020  
Laser Safety Class IEC 60825-1/2007, EN 60825-1 Class 1M
FDA (CDRH) 21CFR Part 1040.10
Standards for
Hazardous Location
Class I, Division 2, Groups A, B, C, D T4
FM 3600-2011
FM 3611-2004
FM 3810-2005
Type "n"
II 3 G Ex nA ic [op is] II C T4 Gc X
EN 60079-0:2009, 2012
EN 60079-11:2012
EN 60079-15:2010
EN 60079-28:2007
Class I, Division 2, Groups A, B, C, D T4
C22.2 No. 0-10
CAN/CSA-C22.2 No. 0.4-04
C22.2 No. 213-M1987

Note: Under EU legislation, the manufacturer and the authorized 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).


List of Modules and Modules Descriptions

Type Model Function Explosion Protection
Type "n" NI
DTSX200 Distributed Temperature Sensor DTSX200 Distributed temperature sensor
Power supply module NFPW426 Power supply module
(10 to 30 V DC input)
NFPW441 Power supply module
(100 to 120 V AC input)
NFPW442 Power supply module
(220 to 240 V AC input)
- - -
NFPW444 Power supply module
(21.6 to 31.2 V DC input)
Base module for DTSX200 DTSBM10 Base module for DTSX200
Optical switch module DTOS2 Optical switch module (2ch)
DTOS4 Optical switch module (4ch)
DTOS16 Optical switch module (16ch)
CPU module NFCP050 CPU module  レ
Rack mount kit DTRK10 Rack mount for optical fiber N.A. N.A. N.A.
Optical fiber for DTSX DTFB10 Optical fiber for DTSX N.A. N.A. N.A.

レ: conforming
-: Not conforming yet
N.A.: Not applicable
For the details of the power supply modules and the CPU module, see GS 34P02Q13-01E and GS 34P02Q12-01E.

DTSX200 Module Base (Required)

DTSX200 Module BaseThe base module for DTSX200 is used for mounting various function modules including the DTSX200 distributed temperature sensor, power supply modules, optical switch modules and CPU I/O modules.


Optical Switch Module (Required)

image_958.jpgInstalling an optical switch module (2, 4 or 16-channel model) allows monitoring of multiple optical fibers using a single DTSX200 system.

  • DTOS2: 2 channel Optical Switch Module
  • DTOS4: 4 channel Optical Switch Module
  • DTOS16: 16 channel Optical Switch Module


Power Supply Module (Required)

  • NFPW426: 10 to 30 VDC
  • NFPW441: 100 to 120 VAC
  • NFPW442: 220 to 240 VAC
  • NFPW444: 21.6 to 31.2 VDC


CPU I/O Module (Optional)

ModuleInstallation of a CPU I/O module allows for additional control capability on the DTSX200.

  • NFCP050: 12 AI, 2 AO, 16 DI, 8 DO, 2 PI, 1 AI for battery monitoring



Model DTSX200 DTSX200Distributed Temperature Sensor
Suffix Codes -N Standard type
0 Standard type
9 EAC mark
E E2000/APC
N Basic type
G With ISA Standard G3 option


DTSX200 Module Base

Model DTSBM10 Base module for DTSX200
Suffix Codes -N Standard type
0 Standard type
9 EAC mark
N Basic type
G With ISA Standard G3 option


Optical Switch Module

Model DTOS2 Optical Switch module 2ch
DTOS4 Optical Switch module 4ch
DTOS16 Optical Switch module 16ch
-N Standard type
0 Standard type
9 EAC mark
E E2000/APC
N Basic type
G With ISA Standard G3 option


Power Supply Module

Model Reference (Input voltage range)
NFPW426 10 to 30 VDC
NFPW441 100 to 120 VAC
NFPW442 220 to 240 VAC
NFPW444 21.6 to 31.2 VDC


The development of unconventional resources, such as heavy oil, oil sands and shale gas has been progressing in line with the increase in global energy demand. DTSX200 can measure the temperature distribution along an optical fiber with a length of several kilometers are being applied to extraction of unconventional resources. DTSX200 maximizes oil/gas extraction by providing real time continuous temperature measurement through different injection dynamics. In addition to well optimization, DTSX200 provides critical data that help monitor and detect wellbore conditions for leaks, water penetration and gas breakthrough. DTSX200 also provides control capability (measurement of flow, pressure, temperature, valve position, etc.) on top of fiber optic temperature measurement. More importantly, compared to conventional wellbore monitoring technology, DTSX200 is more robust, cost effective and accurate.

Features Benefits
Ultra low power consumption: 10W Perfect for solar application in remote areas
Operating temperature range: -40 dec C to 65 dec C Perfect for rugged environment without cooling or heating
Fiber optic cable sensor Provides a complete and continuous profile of the downhole well
Control capability with NFCP050 module Monitor and control external devices such as flow, pressure, valve position, temperature, ect.
Wide range of communication protocols Connect to existing DCS, PLC, DAQ and wireless interface
6km optical fiber = 6,000 points! Cost effective way of measuring temperature compared to traditional sensor technology

DTSX200 Oil & Gas 1DTSX200 Oil & Gas 2

Yokogawa DTSX200 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. DTSX200 minimizes the potential power grid network outages and streamlines preventative maintenance process. Because of its immunity to electromagnetic interference, DTSX200 is ideal for high voltage, high noise environment. DTSX200 is designed to deploy in the following environments:

  • Underground power cables
  • Subsea power cables
  • Overhead power lines
  • Distribution station
  • Substations
Features Benefits
Isolation from electromagnetic interference Fiber optic is isolated from electrical magnetic current
Real time temperature measurement and monitoring Measure and monitor real time power grid/cable temperature
Measure and monitor multiple power circuits/cables Up to 16 channels of optical switch can be connected
Report and data analysis Access historical data using HTTP, SFTP or web browser
Wide range of communication protocols Connect to existing DCS, PLC, DAQ and wireless interface
6km optical fiber = 6,000 points! Cost effective way of measuring temperature compared to traditional sensor technology

DTSX200 Pipeline 1DTSX200 Pipeline 2

Yokogawa DTSX200 offers superior pipeline leak detection by using fiber optic solutions that provide a complete temperature profile along the entire length of a pipeline. When a leak occurs anywhere along the pipeline, a localized temperature change is produced at that specific location. The optical fiber cable, due to its close proximity to the pipeline, has adequate thermal contact and can provide accurate temperature readings. By comparing every new temperature profile scan acquired against a reference profile taken under normal conditions, it is possible to detect temperature anomalies which may indicate a possible pipeline failure or external extrusion which might result in or be an actual break. DTSX200 is designed to deploy in the following applications:

  • Gas pipelines: Ammonia, natural gas, carbon dioxide
  • Liquid pipelines: Crude oil, heated oil, gasoline, PNG, LNG, brine, steam

A leak induced temperature change can be either from a localized cooling or heating. For leaks occurring in pipelines carrying crude oil and other similar products, it is expected that a localized warming will result from a leak as it is often a common practice to transport the crude at a warm temperature to reduce its viscosity.

Leaks in pressurized gas pipelines or those carrying LNG or other cryogenic products, a localized cooling effect will be observed as a result of the Joule Thompson effect, whereby a rapidly expanding gas under pressure lowers the surrounding temperature.

Pipeline Leak Source

Gas Expands, Temperature Decreases

Feature Benefits
1m special resolution Identify the exact location of the leak/failure
Up to 0.1°C temperature resolution Possible leak detection within the first 1 minute of occurrence *
Fiber optic cable sensor Real time, accurate and continuous detection of gas, oil and fuel pipeline leaks
Report and data analysis Access historical data using HTTP, SFTP or web browser
Wide range of communication protocols Connect to existing DCS, PLC, DAQ and wireless interface
6km optical fiber = 6,000 points! Cost effective way of measuring temperature compared to traditional sensor technology

* Assuming appropriate scan rate and data refresh intervals are used

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 DTSX200 is designed to detect fire in critical assets under the most extreme conditions and offers unmatched reliability, performance and cost savings.

Yokogawa's DTSX200 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
Feature Benefits
1m special resolution Identify the exact location of the fire
Up to 0.1°C temperature resolution Possible fire detection within the first 10 seconds of occurrence *
Fiber optic cable sensor Unlike discrete sensor or IR camera, fiber optic cable eliminates "blind spots"
Coated fiber optic cable Immune to dust, humidity, corrosion and dirt
Report and data analysis Access historical data using HTTP, SFTP or web browser
Wide range of communication protocols Connect to existing DCS, PLC, DAQ and wireless interface
6km optical fiber = 6,000 points! Cost effective way of measuring temperature compared to traditional sensor technology

* Assuming appropriate scan rate and data refresh intervals are used

DTFB10 Optical Fiber

The optical fiber for DTSX is used for checking the operation of the DTSX200.DTFB10 Optical Fiber


DTRK10 Rack Mount kit (Optical Fiber Tray)

The rack mount kit can be used for laying optical fibers in a cabinet.DTRK10 Rack Mount kit


DTAP200 DTSX200 Control Visualization Software

DTAP200 DTSX200 Control Visualization SoftwareThe DTSX200 Control Visualization Software (DTAP200) is used to control the DTSX200 and visualize DTS data on a PC. The DTAP200 is used to configure and control the DTSX200, as well as display measurement data graphs and generate LAS format. DTAP200 option allows a user to perform control, monitoring and analysis from anywhere on Ethernet network.


DTAP200D Data Conversion Software

The Data Conversion Software option (DTAP200D) allows the DTSX200 to generate data files in WITSML format. When the DTSX200 is configured for WITSML conversion using DTAP200D, then the DTSX200 will generate data files in WITSML format.



Notas de Aplicación

A belt conveyor fire detection solution employing the DTSX distributed optical fiber temperature sensor can greatly reduce crises that can threaten a company's survival.

Notas de Aplicación

Temperature Monitoring Solution for 
Quick Detection of Fires in Fume Ducts


With industrial and economic development comes increasingly large and advanced power plants and factories. Nevertheless, we find many cases where the original cables, cable tunnels, and other components of the power infrastructure have languished under continuous operation.


Reactor/Furnace Wall Healthiness Monitoring with a Fiber Optical Temperature Sensor

Notas de Aplicación

Temperature Monitoring Solution for Maximum VSD Operating Efficiency


The DTSX is a reliable and robust tool for fire detection over long distances and large areas, such as tunnels.


Recently, several ARC Advisory Group analysts and management team members had a chance to sit down with the new Yokogawa President and COO, Mr. Takashi Nishijima, and several other top Yokogawa executives to discuss the company's burgeoning presence in the worldwide upstream and midstream oil & gas industry.

Reporte Técnico de Yokogawa

The development of difficult to recover unconventional energy resources, is progressing. Figure 1 shows an example of how unconventional heavy oil is extracted from tar sand by reducing its viscosity with steam. To ensure efficient mining, changes in the underground temperature distribution will need to be monitored.



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