The Mineral-Insulated Thermocouple (Mantelteckenelement) Type K product line manufactured by Reckmann GmbH (Germany) represents a specialized industrial temperature instrumentation portfolio engineered to operate reliably in severe high-temperature environments, corrosive flue gases, and intense mechanical vibration regimes. Operating on the Seebeck thermoelectric effect utilizing standardized NiCr-Ni (Nickel-Chromium / Nickel-Alumel) thermoelement pairs conforming to international standard IEC 60584-1 / DIN EN 60584, these sensors provide a highly linear, precise, and sensitive millivolt (mV) output across an extensive thermal span from -40°C up to +1100°C (with intermittent peak excursions up to 1200°C).

The portfolio provides three specialized mechanical configurations tailored to resolve spatial constraints and complex process monitoring demands:
1. Thermocouple 1 x Type K Ø3.6: A simplex single-circuit configuration with an ultra-slender outer sheath diameter of Ø3.6 mm. This streamlined profile yields exceptionally low thermal mass and ultra-fast dynamic response kinetics (virtually zero thermal lag), enabling immediate detection of transient thermal spikes in combustion chambers or high-velocity exhaust flues. Its ductile metallic construction allows flexible on-site contouring along intricate pipe runs without compromising internal dielectric insulation.
2. Thermocouple 4 x Type K Ø4.5: An extraordinary engineering achievement packing four completely independent Type K thermocouple circuits into a compact outer diameter of just Ø4.5 mm. This serves as an ideal solution where installation clearance is tightly constrained yet maximum process security is mandated: functioning either as a 4-channel redundant safety system (Quad Redundancy routing simultaneous signals to DCS, PLC, and independent emergency shutdown interlocks) or as a multi-tier profile sensor with staggered measuring junctions positioned along the stem for thermal gradient profiling.
3. Thermocouple 4 x Type K Ø6.1: A heavy-duty quad 4-circuit thermocouple housed within a rugged Ø6.1 mm outer sheath. The increased wall thickness delivers superior mechanical bending strength and resistance against abrasive momentum loads in fluidized catalyst beds, blast furnaces, and heavy power plant steam circuits.

Internally, all conductor pairs are embedded in high-purity (>99.6%), densely compacted Magnesium Oxide (MgO) powder, delivering flawless electrical isolation across all eight conductors and the outer metallic sheath even at temperatures exceeding 1000°C. The outer protective sheath is forged from heat-resistant Inconel 600 (Alloy 2.4816) or high-temperature stainless steel (AISI 310 / 1.4841), providing impervious defense against high-temperature oxidation, hydrogen embrittlement, and sulfur attack in hostile combustion atmospheres.

• Manufacturer: Reckmann GmbH
• Country of Origin: Germany
• Product Models Covered:
  - Thermocouple 1 x Type K Ø3.6 (Simplex single-circuit thermocouple, probe diameter Ø3.6 mm)
  - Thermocouple 4 x Type K Ø4.5 (Quad four-circuit thermocouple, compact probe diameter Ø4.5 mm)
  - Thermocouple 4 x Type K Ø6.1 (Quad four-circuit thermocouple, heavy-duty probe diameter Ø6.1 mm)
• Thermocouple Calibration: Type K (NiCr-Ni / Nickel-Chromium vs. Nickel-Alumel)
• Governing Standards: IEC 60584-1 / DIN EN 60584, ANSI MC96.1
• Accuracy Class: Class 1 per IEC standard (±1.5°C or ±0.0040 x |t|)
• Nominal Operating Temperature Range: -40°C to +1100°C (intermittent peaks up to +1200°C)
• Measuring Junction Style (Hot Junction):
  - Insulated / Ungrounded (standard, for superior electromagnetic noise rejection)
  - Grounded (optional, for ultra-rapid response times)
• Internal Insulation: High-density compacted Magnesium Oxide (MgO) powder (>99.6% purity)
• Sheath Material: Inconel 600 (Nickel-Chromium Alloy 2.4816) or High-Temp Stainless Steel 1.4841 (AISI 310)
• Flexibility / Bendability: Minimum bending radius of 5 x sheath diameter (excluding measuring tip 50mm zone)
• Insulation Resistance: > 1000 MΩ x m at 500V DC test voltage (measured at 20°C ambient)
• Sheath Immersion Length: Fully customizable per engineering drawings from 100 mm to over 10000 mm
• Termination Options: Industrial Form B/BUZ cast aluminum terminal head, miniature ceramic connectors, or high-temp braided extension leads
• Ingress Protection Rating: IP65 / IP67 depending on terminal connection housing