Surface Thermometers

Surface Thermometers

Surface thermometers are non-invasive temperature assemblies that measure process temperature by contacting the outside surface of a pipe, reactor, or vessel rather than penetrating the pressure boundary. This approach is broadly applicable across industries and is particularly attractive in heavy-duty services with demanding process conditions. Surface measurement is also well suited for retrofits, energy monitoring, safety monitoring, and temporary measurement campaigns where rapid deployment and repositioning are valuable.

The application fit strengthens as process conditions become more challenging for intrusive measurement points. Surface assemblies are suited to high flow velocities and high process pressures, highly viscous or corrosive media, abrasion, pigging operations, and small pipe diameters. These conditions are common in heavy-duty industries such as chemical/petrochemical, power and energy, and mining/minerals/metals, where protecting the pressure boundary and avoiding flow disturbance can be primary drivers.

Key benefits follow directly from non-contact-with-medium installation. With no direct process contact, there is no leakage risk at the measuring point and no thermowell wear from corrosive or abrasive media. Installation can often be performed without shutting down the process and without extensive engineering tasks associated with intrusive designs (for example, thermowell wake-frequency calculations). Because the assembly does not intrude into the flow path, it avoids impacting flow steadiness.

Surface thermometer portfolios typically include both high-performance and foundational variants. Advanced non-invasive instruments can use RTD or TC sensing with high accuracy for demanding monitoring tasks, while fundamental RTD surface thermometers address basic monitoring where simplicity and speed of installation are priorities. This range supports consistent measurement philosophy across permanent installations, temporary studies, and staged retrofit programs.

For fired equipment and high-heat-transfer assets, specialized “skin point” assemblies can be engineered to measure pipe skin temperature and help detect internal build-up on pipe walls. These assemblies are designed to maintain thermal continuity under severe conditions such as vibration, corrosion, and differential thermal expansion, and may incorporate reinforced thermocouple tips, high-grade materials, and optimized expansion features to accommodate distortion while preserving measurement stability.

George E. Booth Co., an exclusive authorized representative of sales and service for Endress+Hauser.