An explosion-proof (flameproof) thermocouple is a temperature sensor built for use in hazardous (classified) areas where flammable gases, vapors or dust may be present. Its defining feature is a flameproof enclosure (Ex d) — a thick-walled die-cast aluminum or stainless-steel terminal head with precisely machined flamepath joints, designed per IEC 60079-1 / GB 3836.1 & 3836.2. If an internal explosion occurs, the housing contains the blast and quenches the flame, preventing ignition of the surrounding atmosphere.

Key features:

• Flameproof construction (Ex d IIC T6 Gb) — robust flamepath sealing; explosion contained inside the head, sparks and hot gas cannot escape

• Covers the highest gas group IIC (hydrogen, acetylene) with temperature class T6 (max. surface temperature ≤ 85 °C); higher temp classes T5–T1 available

• Suitable for Zone 1 & Zone 2 gas hazardous areas (Ex d); intrinsically safe versions (Ex ia / Ex ib) available for Zone 0 and dust zones 20–22

• Calibration types: K, N, E, J, T (0–1300 °C) — S, R, B options for high-temperature processes

• Certifications: CNEx / NEPSI (China, GB 3836), ATEX, IECEx and other national approvals — mandatory for hazardous-area use

• Rugged sensor assembly: sheathed (MIMS) sensing element with threaded or flanged process connection, often installed in a thermowell for pressure and vibration protection

• Reliable and maintenance-friendly — standard thermocouple output (mV) works with existing indicators, recorders and control systems

Typical applications: petroleum refineries (distillation columns, catalytic cracking, hydrocracking), chemical plants (reactors, distillation towers, storage tanks, heat exchangers), gas processing (dehydration, sweetening, LNG facilities), pharmaceutical solvent areas, and dust-hazard environments such as flour mills and cg.oal powder handling