A bayonet style thermocouple is a heavy-duty temperature sensor that utilizes a bayonet cap and adapter mechanism to secure the sensor tip firmly against a surface or thermal wall. The TC44 bayonet thermocouple probe features a stainless steel flexible armor cable and adjustable bayonet capn, ensuring positive thermal contact and fast response times in plastic extrusion, molding machinery, and process heating systems.

The TC44 Flexible Armored Bayonet Thermocouple is available in Type J and Type K calibrations for a wide range of industrial temperature measurement applications. While the thermocouple sensing element is capable of measuring elevated process temperatures, the maximum continuous operating temperature of the complete assembly is also determined by the selected lead wire insulation. Teflon-insulated lead wire is suitable for applications up to 205°C (401°F), Fiberglass up to 510°C (950°F), and High-Temperature Fiberglass up to 704°C (1300°F). For applications where the process temperature exceeds the lead wire rating, the transition and lead wire must be located outside the high-temperature zone or an alternative construction should be selected.

The adjustable bayonet cap allows the TC44 thermocouple to be positioned at the correct depth for the application before it is locked into the mating bayonet adapter. Proper adjustment helps maintain consistent contact between the thermocouple tip and the measurement surface, improving heat transfer and reducing measurement errors caused by poor sensor contact. Combined with the flexible stainless steel armor, the TC44 can be routed and installed more easily on industrial equipment while maintaining reliable surface temperature measurement

Install the TC44 by first securing the bayonet adapter into the mounting hole or threaded fitting. Next, adjust the bayonet cap along the flexible armored section to achieve the required immersion depth for the application. Once the desired position is set, align the bayonet cap with the adapter pins, push it into place, and rotate approximately 90° until it locks securely. Proper adjustment helps maintain consistent contact between the thermocouple tip and the measurement surface for reliable temperature measurement.

Stainless steel flexible armor acts as an impenetrable shield around insulated lead wires, protecting them against mechanical abrasion, continuous cable flexing, sharp equipment edges, and hot plastic splashes common in extrusion and industrial process heating applications.

Selecting the right configuration depends on your equipment and application. Start by choosing a bayonet adapter that matches the thread size and mounting depth of your machine. Next, select a bayonet cap that is compatible with the adapter and allows the immersion depth to be adjusted so the thermocouple tip stays firmly against the measuring surface. Finally, choose the sheath diameter based on your operating conditions. A 3/16" (4.8 mm) sheath is the most common choice because it offers an excellent balance of fast response and mechanical strength, while smaller diameters provide quicker response and larger diameters are better suited for heavy-duty or high-vibration applications.