Surface Thermometers

Surface Thermometers

Surface thermometers (non-invasive thermometers) measure medium temperature by contacting only the outside surface of a pipe, reactor, or vessel, rather than penetrating the process boundary. This measurement concept is particularly attractive where direct immersion is impractical, where process penetration introduces unacceptable risk, or where rapid retrofit and repositioning are important. The technology is positioned for broad applicability across industries, with particular relevance in heavy-duty processes with demanding conditions.

The principal benefit is obtaining actionable temperature information without becoming a pressure boundary component. Eliminating a wetted penetration removes a common source of leakage risk and avoids the mechanical load cases that drive thermowell sizing and vibration concerns. Non-invasive sensors are also well-suited for temporary studies, energy monitoring initiatives, and safety-driven retrofits because installation can be performed without shutting down the process and without altering the flow profile.

Surface assemblies are framed as ideal for high flow velocities, high process pressures, highly viscous or corrosive media, abrasive services, pigging operations, and small pipe diameters - conditions that can complicate or accelerate wear of intrusive designs. Benefits explicitly associated with the approach include: no direct contact with the medium; no leakage risk; no extensive engineering such as thermowell wake-frequency calculation; no shutdown requirement; no impact on flow steadiness; and avoidance of thermowell wear in corrosive or abrasive services.

Typical applications include energy and safety monitoring of pipe networks, reactor and vessel skin temperature observation, retrofit measurement points for utilities and steam systems, and temporary or mobile measurement campaigns across different lines in a facility. Because mounting can be repositioned, these sensors support iterative optimization efforts such as insulation assessment, heat-loss evaluation, and verification of heat-tracing performance.

Selection focuses on required accuracy and response behavior, mounting method and surface condition, expected ambient exposure, and the degree of process variability. Where the measurement objective demands non-intrusive installation with minimized operational disruption, surface thermometers provide a practical path to improved temperature visibility.

Forberg Smith, an exclusive authorized representative of sales and service for Endress+Hauser.