Cable Probes

Cable Probes

Cable probes are compact RTD and thermocouple thermometers built with a non‑removable, flexible cable and a sheath that is in direct contact with the process medium. They are supplied either without a process connection for plug‑in use, or with common connections such as compression fittings and threaded adapters, plus special options such as weld‑on pads or bayonet locks. The format is suited to tight spaces and measuring points that require the sensor to bend, and it is commonly applied in machinery, HVAC, storage monitoring, laboratory equipment, autoclaves, bearings, and even high‑pressure or cryogenic duties.

Construction typically centers on a robust sensing element (RTD for high accuracy and stability, or thermocouple for wide temperature range and fast response) paired with a protective sheath and a cable jacket selected for the ambient environment. Because the sensing sheath is the measurement interface, sheath material and surface finish directly influence survivability in corrosive or erosive media and in washdown or condensation-prone areas.

The primary benefit is placement flexibility without sacrificing measurement integrity. Cable routing can be optimized around obstructions and moving assemblies, while the small probe footprint reduces mechanical loading on nozzles and minimizes heat-sink effects. Direct immersion designs also deliver rapid response compared with heavy protection tubes, improving control performance for fast-changing processes.

Typical uses span equipment temperature monitoring (bearings, motors, heated tooling), utility systems (air handlers, boilers, chilled water), and batch assets (autoclaves, thermal chambers). Where penetration is undesirable or geometry is complex, cable probes can also be arranged to support surface monitoring schemes on reactors or vessels while keeping installation simple.

Selection is usually driven by temperature range, required accuracy, vibration, and chemical compatibility. Key choices include RTD wiring method (2/3/4‑wire), thermocouple type and reference handling, strain relief, minimum bend radius, ingress protection at the termination, and whether a local or remote transmitter is needed to harden the signal for long cable runs.

Instrumentation and Controls., an exclusive authorized representative of sales and service for Endress+Hauser.