A sheathed thermocouple (also called mineral-insulated metal-sheathed / MIMS thermocouple, 铠装热电偶) is a temperature sensor in which thermocouple wires are embedded in a compacted magnesium-oxide (MgO) powder insulation inside a seamless metal sheath (stainless steel SS304/316/310 or Inconel), then swaged and cold-drawn into a solid cable-like structure.

Key features:

• Compact and bendable — can be pre-formed or bent on site (bending radius ≥5× diameter); ideal for narrow, cramped or curved installation paths

• Fast thermal response — reduced dynamic error (fine-diameter versions reach t₀.₅ ≤ 0.5 s)

• Rugged construction — high mechanical strength, pressure resistance, vibration and shock resistance, long service life

• Wide temperature range — from -200 °C up to 1300 °C depending on type and sheath material

• Calibration types per IEC 60584 / GB/T 16839: K, N, E, J, T, S, R, B (single or dual element)

• Junction options: grounded (fastest response) and ungrounded (electrically isolated) types

• Sheath diameters: Φ1–Φ8 mm; sheath materials: SS304, SS321, SS316, SS310, Inconel (GH3030/GH3039/Inconel 600)

• Configurable assemblies: connection head (junction box), process connections (M16×1.5, M27×2 threads, movable sleeve, flanges), and custom lengths; can also be used as the sensing element inside an assembled thermocouple

Typical applications: petrochemical, electric power, metallurgy, machinery, aviation, nuclear and kiln/furnace industries — measuring the temperature of liquids, vapors, gases and solid surfaces in processes, pipelines, boilers, exhaust systems and other demanding locations.