DTSX1 Fiber Optic Heat Detector

The DTSX1 is an all-in-one, self-contained fiber optic temperature solution. It protects your equipment and devices against abnormal heat events while being more affordable and convenient than other heat detection solutions.

The DTSX1 measures temperature and detects heat with a fiber optic cable over a wide area quickly and precisely. Alarm displays and sounds are individually configurable to suit your applications, enabling rapid detection, localization, and identification of abnormalities to prevent heat-induced equipment failure or catastrophic fire events.

The DTSX1 is a compact easy-to-deploy solution with integrated I/O and visual alarm panel integral to the design.


  • Easy-to-handle heat detector in a single box
  • Single optical fiber cable for rapid heat detection
  • Seamless integration with Yokogawa's systems products
  • Can be used as a standard system in conjunction with the GA10


  • Abnormal temperature monitoring of cable racks, and bus bars
  • Fire detection on combustible ducts
  • Fire detection on conveyor belts
  • Fire detection in cable tunnels
  • Furnace skin temperature monitoring


DTS Technology

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 phenomenon is also true when you shoot a pulse of light (laser pulse) off of a molecule, in this case, the fiberglass 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).

The Raman signal is the signal used for evaluation of temperature. It is sufficiently strong and has a unique temperature dependence. Its wavelength is also shifted substantially (about 40/Nm) from the main Rayleigh peak, thereby allowing the dominant Rayleigh and Brillouin peaks to be filtered out.

The Raman signal is comprised of the so-called “Stokes” and “anti-Stokes” bands. The Stokes band at the higher wavelengths (redshifted) is stable with little temperature sensitivity. The anti-Stokes band at the lower wavelengths (blue shifted) exhibits a temperature sensitivity, where the higher the energy within the band, the higher the temperature and vice versa. A ratio of the energy or area within the Anti-Stokes band to that of the Stokes band can be simply related to the temperature of the fiber optic line at the depth where the signal originated.


Measuring distance 2 ,4, 6, 8, 10, 16km
Number of channels 1, 2, 4
Sampling resolution Measuring temperature at 1-meter intervals
Minimum temperature measurement time 5 seconds
Relay outputs 64 max, 30 VDC @ 1amp
Relay inputs 4, 12 to 30 VDC @ 5 mA DC
Power consumption 30 Watts (normally 15 Watts at ambient air temperature of 23 C)
Power supply 10 to 30 VDC
External dimensions 500(W) x 500(H) x 250(D) mm
Weight 28kg



Yokogawa’s distributed temperature sensors ensure comprehensive monitoring of thermal events in real-time, limiting facility damage by decreasing the risk of fire/duct explosions in exhaust air/fume ducts, allowing for early detection and quick response.


Reducing waste in the separator and electrode drying furnaces with Yokogawa’s distributed temperature sensors ensure comprehensive monitoring of thermal events in real-time.


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.

Application Note

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.


Hot Spot Monitoring for Safety with a Fiber Optical Temperature Sensor

Application Note

Temperature Monitoring Solution for Maximum VSD Operating Efficiency


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.




Yokogawa address misconceptions on how Distributed Temperature Sensing (DTSX) works and what industries use them.

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