The industrial RTD Measuring Insert series manufactured by Reckmann GmbH (Germany) represents the quintessential temperature sensing core designed for precise insertion into thermowells or standardized Form B/DIN connection heads. Featuring integrated spring-loaded mounting fixtures on the terminal base, the insert continuously presses firmly against the thermowell bottom. This minimizes contact thermal resistance, achieves exceptionally fast thermal response kinetics, and dampens fluid-induced vortex vibration under high flow velocities.

The portfolio comprises four dedicated models tailored to specific hazardous area certifications and field termination topologies:
1. Type 143 (Standard with Ceramic Terminal Block): Equipped with a heavy-duty ceramic terminal block per DIN 43762 featuring nickel-plated brass screws, ensuring robust, vibration-resistant, and corrosion-proof wire connections in general industrial environments.
2. Type R144 (Ex) (Explosion-Proof with Ceramic Terminal Block): Fully certified according to rigorous international ATEX and IECEx standards (Ex i - Intrinsic Safety). Specifically designed for safe and continuous deployment in hazardous gas atmospheres (Zone 0, Zone 1, Zone 2) and combustible dust zones (Zone 20, Zone 21, Zone 22) found in refineries, petrochemical complexes, and gas compressor stations.
3. Type R146 (Standard with Flying Leads): Instead of a bulky terminal base, this variant delivers flame-retardant PTFE insulated free flying leads, ideal for direct integration with in-head circular puck transmitters (4-20mA / HART / Profibus) or compact spatial housings.
4. Type R149 (Ex) (Explosion-Proof with Flying Leads): Combines intrinsic explosion safety (ATEX/IECEx) with the convenience of flexible flying leads, providing the ultimate solution for compact smart field instrumentation in explosive environments.

The entire stem of each insert is constructed using mineral-insulated metal-sheathed (MgO) cable technology sheathed in high-grade stainless steel (AISI 316Ti / AISI 316L). The densely compressed magnesium oxide powder provides exceptional electrical isolation even under elevated thermal stresses, protects the delicate Pt100/Pt1000 platinum elements against extreme shocks, and allows the probe stem to be flexibly bent to navigate convoluted routing paths without compromising performance.

• Manufacturer: Reckmann GmbH
• Country of Origin: Germany
• Product Models Covered:
  - Type 143: Standard RTD measuring insert with ceramic terminal block
  - Type R144 (Ex): Explosion-proof ATEX/IECEx RTD measuring insert with ceramic terminal block
  - Type R146: Standard RTD measuring insert with free ends / flying leads
  - Type R149 (Ex): Explosion-proof ATEX/IECEx RTD measuring insert with free ends / flying leads
• Sensing Resistor: Pt100 or Pt1000 per DIN EN 60751 (Single 1xPt100 or Dual 2xPt100 options)
• Wiring Configurations: 2-wire, 3-wire, or 4-wire circuits (4-wire circuit completely eliminates lead resistance errors)
• Accuracy Tolerance: Class B (±0.3°C at 0°C), Class A (±0.15°C at 0°C), or high-precision 1/3 DIN
• Operating Temperature Range:
  - Thin-film sensors: -40°C to +500°C
  - Ceramic wire-wound sensors: -40°C to +600°C (Extended cryogenic range down to -196°C on request)
• Sheath Diameters: Ø3.0 mm, Ø4.5 mm, Ø6.0 mm, Ø8.0 mm
• Immersion Lengths: Fully customized to fit any thermowell from 50 mm up to 2000 mm
• Explosion Safety Certifications (For Models R144 & R149): ATEX / IECEx intrinsically safe Ex i (Gas: Zone 0/1/2; Dust: Zone 20/21/22)
• Spring Loading: Dual spring-loaded mechanism with 10 - 15 mm travel for guaranteed thermowell bottom contact
• Sheath Material: Stainless steel AISI 316Ti (1.4571) or AISI 316L (1.4404)
• Internal Insulation: High-purity densely compacted Magnesium Oxide (MgO) powder
• Insulation Resistance: > 100 MΩ at 500V DC test voltage (tested at 25°C ambient)