Tunable Diode Laser Spectrometers

The TruePeak Tunable Diode Laser Spectrometers (TDLS) operate by measuring the amount of a laser light that is absorbed as it travels through the gas being measured. The TDLS line offers measurements for process gas, flue gas, impurity analysis, custody transfer, safety, with in-situ and extractive methods supported. By utilizing no sensor contact with the process and no moving parts, it leads to a high mean time between failures (MTBF) and hence a low long term cost of ownership (LTCO).

"I just want to make sure that there are no major incidents that occur."

"I need to make sure that we meet regulation standards."

Key Benefit

Industry best practices and standards acknowledge TDLS as the technology required for safe and environmentally responsible combustion applications.

  • SIL 2 and 3 certification
  • Not an ignition source
  • Fast response time (< 5 seconds)
  • No background interferences

Key Benefit

  • Minimal maintenance
  • In-situ installation removes the need for sample handling
  • Sensor is isolated from corrosive and aggressive process components
  • On-board diagnostics with 50 days of spectral and historical data
  • Fully field serviceable

"I need to make sure that all the PMs get done in an 8hr day without any surprises."

"I need to minimize the maintenance turnaround times." 

"I need to be able to chat with a specialist about detailed questions."

"Getting quotes even for simple products is time-consuming when I have to take time out of my already packed day to follow on status." 

Key Benefit

  • Dedicated application and post-sale resources guarantee timely quotations and response
  • Filling out data sheet or contact us will ensure the fastest possible response

Key Benefit

  • Dedicated support staff and regional support specialist are available to help you tailor the appropriate products to your application needs
  • Analytical technical specialist are available to help assess current analyzer installation and provide recommendation or justify ROI for installations
  • Full turnkey startup and commissioning for users with limited resources

"We use old technology because we can't seem to justify the upgrade."

"I am concerned with the plant engineering resources utilized to make modifications or maintain the systems. There just is not enough people."

The TDLS220 is specifically designed for accurate, reliable and low maintenance measurement of volume percent (vol%) oxygen (O2) for safety and process applications. It is a viable alternative to paramagnetic O2 analyzers.

Yokogawa’s new TDLS8000 houses all of the industry’s leading features in one robust device. The platform design is for in situ measurements which negates the need for sample extraction and conditioning.

Yokogawa’s new TDLS8100 continues to house all of the industry’s leading features from the TDLS8000, but now only requiring a single-flange installation. An in-situ measurement with a probe removes the requirement for sample extraction and conditioning and can be used in a variety of aggressive process conditions.

In-Situ Measurement Allows for Quick Analyzer Response 

Tunable diode laser spectrometers (TDLS) allow for real-time gas analysis that lead to increased efficiency, safety, throughput, quality, and environmental compliance. The non-contacting sensor allows measurements in the most severe conditions, such as high temperature, high pressure, corrosive/abrasive conditions, and high dust loading. This in-situ analyzer eliminates the need for sample handling and extraction and reduces the need for routine maintenance and calibration.

>>>Application Notes 

Improved OPEX and safety

The TDLS8000 is attracting considerable attention from many refinery and petrochemical plants because it requires little maintenance and can measure the concentrations of O2 and CO/CH4 in the radiant section of large-scale combustion furnaces and process heaters in near real-time. This allows an unprecedented opportunity to optimize combustion efficiency leading to increased throughput, reduced emissions, and increased overall asset safety. 

>>> Solutions


The ammonia (NH3) gas is injected to remove the NOx and thus reduce the NOx concentration in the stack flue gas. With conventional NH3 analyzers that perform measurements indirectly, NH3 concentrations are obtained through a sampling system. Therefore, there are problems with the maintenance and running costs of the sampling system, and time delays in measurement. The TDLS8000 Laser Analyzer is the solution to all these problems.


Electrolysis plants create hydrogen and chlorine from a brine solution. Chlorine gas generated from the anolyte of the electrolysis tank generally contains between 0.5 to 2.0 vol% H2O. The sample is then cooled and filtered to remove brine, subsequently coming out as wet chlorine gas. The wet gas is sent to a drying tower where it is treated with sulfuric acid to get moisture down to the ppm level. 


In maintaining and managing industrial plants, monitoring waste water pH/ORP is both a legal obligation and an unavoidable necessity for protecting the environment. Monitoring without an attentive eye can lead to severe consequences.


Considering safety and environmental issues such as combustion efficiency and decreasing NOX and CO in exhaust gas, it has become important to control O2 concentration in garbage incineration processes.

Yokogawa Technical Report

In recent years, shale gas extraction technology has made rapid progress, inducing a shale gas revolution mainly in the USA. Thus, the need for analysis of hydrocarbon gases, including natural gas, is expected to grow rapidly. Traditionally gas chromatography has been used for the analysis of hydrocarbon gases; it can accurately measure the concentration of each hydrocarbon component in a sample of natural gas.


Combustion furnaces such as heating furnaces and boilers in plants include various sizes and types, and serve as energy sources, that is, they are cores in all production activities. Because a large amount of fuel such as gas or fuel oil is consumed in plants, their combustion efficiency directly affects the performance and running cost of the plants. 


Tunable diode laser analyzers optimize combustion through direct measurement of O2, CO and methane.


Spectrometric technology can assess many critical characteristics about products, but it has limits. It can be challenging to determine when the line has been crossed


With fired heaters, users hope to get greater efficiency and reduced emissions but often are disappointed. Given the number of fired heaters operating every day and their importance in the process industries, any improvements realized across the board will have huge impacts. More units can reach their potential with some simple changes in work practices and technology upgrades.

The TDLS8000 is non-incendive and does not require a purge to maintain hazardous ratings. Purge gas is required to keep the electronics and process windows cool, clean, and dry. Average consumption can run between 50-120 standard liters per min. ...
Edition 1

The TDLS8000 is non-incendive and does not require a purge to maintain hazardous ratings. Purge gas is required to keep the electronics and process windows cool, clean, and dry. Average consumption can run between 50-120 standard liters per min.

Product Overviews



    Yokogawa Advanced Solutions recently sat down with László Cserna, Senior Project Manager at MOL Group where together we recently implemented the Yokogawa CombustionONE Furnace Optimisation Solution.


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