Non-invasive Temperature Measurement Without Process Intervention

The Endress+Hauser iTHERM SurfaceLine TM611 is a non-invasive thermometer designed to measure process temperature directly from the outside of pipes without penetrating the process.

Unlike conventional thermometers that require thermowells, nozzles or pipe modifications, the TM611 is mounted directly on the external pipe surface. This design eliminates potential leakage points and allows temperature measurement without interrupting the process.

The TM611 is especially suitable for applications where:

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  Process opening is undesirable
  
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  Leakage risks must be minimized
  
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  Existing pipelines cannot be modified
  
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  Maintenance downtime needs to be reduced
  

Advanced Thermal Coupling Design for High Accuracy

A key feature of the TM611 is its specially designed thermal coupling element, which improves heat transfer between the process pipe and the temperature sensor.

The optimized geometry reduces heat transfer resistance and minimizes the influence of ambient conditions, enabling accurate temperature measurement even without direct immersion into the process medium.

Compared with traditional surface thermometers, the TM611 achieves improved measurement performance through:

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  Optimized thermal conductivity
  
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  Reduced measurement errors
  
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  Improved response time
  
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  Stable temperature transmission
  

Alternative Solution to Invasive Thermometers

For many industrial applications, conventional temperature measurement requires a thermowell installed inside the process pipe. This can involve additional costs, welding work, inspections and potential pressure boundary concerns.

The TM611 provides an alternative approach by offering:

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  No thermowell required
  
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  No process penetration
  
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  No risk of process leakage
  
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  Simplified installation
  
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  Reduced engineering and maintenance effort
  

This makes it particularly valuable for existing plants where adding traditional temperature measurement points would require significant modification.

Suitable for Harsh Industrial Conditions

The TM611 is designed for challenging process environments where reliable temperature measurement is critical.

Typical applications include processes with:

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  High pressure conditions
  
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  High flow velocities
  
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  Corrosive or aggressive media
  
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  Highly viscous fluids
  
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  Abrasive media
  
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  Small pipe diameters
  

Because the sensor remains outside the process, it provides additional safety advantages while maintaining reliable temperature monitoring.

Flexible RTD and Thermocouple Configuration

The TM611 supports both RTD and thermocouple (TC) measurement technologies, allowing users to select the appropriate sensor type according to application requirements.

The thermometer can also be combined with Endress+Hauser temperature transmitters supporting common industrial communication protocols, including:

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  4…20 mA
  
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  HART
  
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  IO-Link
  
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  PROFINET
  
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  PROFIBUS PA
  
• 
  FOUNDATION Fieldbus
  

This enables easy integration into modern process control systems.

Improved Safety and Lower Installation Costs

By eliminating the need for process penetration, the TM611 helps improve plant safety and simplify project execution.

Benefits include:

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  Reduced leakage risk
  
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  Less installation work
  
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  No thermowell and nozzle costs
  
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  Reduced inspection requirements
  
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  Faster installation on existing pipelines
  

The non-invasive design makes it a practical choice for temperature monitoring upgrades, energy monitoring systems and safety-related applications.

Applications Across Multiple Industries

Power Generation

The TM611 can be used for temperature monitoring in power plant systems where reliability and safety are critical.

Typical applications:

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  Steam systems
  
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  Heat exchangers
  
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  Energy monitoring
  
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  Auxiliary systems
  

Chemical and Petrochemical Industry

Suitable for processes where process opening and leakage risks need to be minimized.

Applications:

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  Process pipelines
  
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  Reaction systems
  
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  Utility monitoring
  
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  High-pressure applications
  

Oil and Gas Industry

The TM611 provides safe temperature measurement for pipelines and process equipment.

Applications:

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  Existing pipeline monitoring
  
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  Flow systems
  
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  Process optimization
  

Industrial Utilities

The non-invasive installation method makes the TM611 suitable for facility-wide temperature monitoring.

Applications:

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  Heating systems
  
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  Cooling circuits
  
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  Energy management systems