Application & Operating Conditions
This 200 °C, 300 V shielded RTD sensor cable is engineered for 3-wire and 4-wire Resistance Temperature Detector (RTD) instrumentation circuits operating in high-temperature industrial environments. Combining 18 AWG fine-stranded nickel-plated copper cores with fluoropolymer insulation and a ~90% coverage nickel-plated copper braid shield, it protects low-level resistance measurements between process temperature probes and control-room transmitters.
3-Wire & 4-Wire RTD Sensor Loops
Connects Pt100, Pt1000 and industrial RTD temperature probes to head/rail transmitters, PLC analog input cards and DCS marshalling cabinets where matched lead-wire resistance compensation is essential.
Heated Process Pipework & Vessels
Built for cable trays, conduit runs and sensor head lead-outs along steam lines, reactor vessels, industrial ovens, autoclaves and thermal fluid skids from −30 °C up to +200 °C (+392 °F).
EMI-Dense Plant Environments
The ~90% optical coverage nickel-plated copper braided screen with continuous drain wire suppresses electrostatic and electromagnetic noise near VFDs, SCR heater banks and power feeders.
Engineering Application Boundary: RTD vs. Thermocouple Circuits
RTD sensors measure temperature via electrical resistance across matched metallic conductors (18 AWG nickel-plated copper) rather than millivolt EMF across dissimilar alloy pairs. Do not substitute alloy thermocouple extension wire (Type K, J, T, E) into RTD bridge circuits, or vice versa.
Routing Rule: Maintain a minimum bend radius of 12 × OD in fixed tray/conduit routing and 15 × OD where subject to equipment vibration or occasional flexing.
Field routing from stainless process pipe RTD transmitter head to local marshalling cabinet.
Cable Construction & Layer Anatomy
Each RTD cable is built from the conductor outward for +200 °C thermal stability and low-noise signal integrity: fine-stranded 18 AWG nickel-plated copper conductors, specially compounded fluoropolymer core insulation, a spiral skived PTFE separator tape, a ~90% nickel-plated copper braid screen with integral drain wire, and a white fluoropolymer outer jacket.
| Layer / Component | Material & Construction Specification |
|---|---|
| 1. Conductors | 18 AWG (approx. 0.82 mm²) fine-stranded nickel-plated copper; resists high-temperature conductor oxidation up to +200 °C |
| 2. Core Insulation | Specially compounded high-temperature fluoropolymer; color-coded for 3-wire (2 Red, 1 White) and 4-wire (2 Red, 2 White) RTD bridges |
| 3. Separator Tape | Spiral-wrapped skived PTFE tape over cabled cores; maintains circular geometry, reduces internal friction and ensures clean stripping |
| 4. Drain Wire | Stranded nickel-plated copper drain wire laid in continuous electrical contact beneath the metallic braid shield |
| 5. Overall Shield | Nickel-plated copper wire braid screen (~90% optical coverage) for high-temperature EMI/RFI shielding |
| 6. Outer Jacket | Specially compounded white fluoropolymer sheath; resistant to heat aging, chemical splash, oils and moisture |
3-Core & 4-Core RTD Cross-Section Geometry: Cabled 18 AWG nickel-plated copper cores wrapped in skived PTFE tape, enclosed by a ~90% NPC braid with drain wire and a white fluoropolymer jacket.
Technical Characteristics
Rated for 300 V RMS instrumentation service from −30 °C to +200 °C (+392 °F), this fluoropolymer-insulated RTD sensor cable delivers stable insulation resistance, low loop impedance and reliable mechanical bend performance across fixed and dynamic industrial routing.
| Parameter | Engineering Specification / Rated Value |
|---|---|
| Cable Category | High-Temperature Shielded RTD Sensor & Instrumentation Signal Cable |
| Rated Voltage | 300 V RMS |
| Conductor Gauge & Stranding | 18 AWG (approx. 0.82 mm²) fine-stranded nickel-plated copper |
| Available Core Counts | 3 Conductors (3-Wire RTD) | 4 Conductors (4-Wire RTD) |
| Max. Continuous Conductor Temperature | +200 °C (+392 °F) |
| Low-Temperature Rating | −30 °C (−22 °F) |
| Static Minimum Bend Radius | 12 × Overall Cable Diameter (OD) |
| Dynamic Minimum Bend Radius | 15 × Overall Cable Diameter (OD) |
| Shield Coverage & Termination | Approx. 90% nickel-plated copper braid with integral stranded nickel-plated copper drain wire |
| Outer Jacket Color & Resistance | White fluoropolymer; resistant to thermal aging, industrial oils, process chemicals and moisture |
Specification & Dimensional Data
Nominal outer diameter, minimum bend radii and cable weight for the 18 AWG 3-conductor and 4-conductor configurations are detailed below in both US customary and metric units.
| Configuration | RTD Circuit Type | Area (mm²) | Nom. OD (in) | Nom. OD (mm) | Static Bend (12×OD) | Dynamic Bend (15×OD) | Weight (lb/1000ft) | Mass (kg/km) |
|---|---|---|---|---|---|---|---|---|
| 18 AWG × 3 Conductors | 3-Wire RTD (Pt100 / Pt1000) | 0.82 | 0.180 | 4.57 | 55 mm (2.16 in) | 69 mm (2.70 in) | 40 | 59.5 |
| 18 AWG × 4 Conductors | 4-Wire Precision RTD Loop | 0.82 | 0.195 | 4.95 | 60 mm (2.34 in) | 75 mm (2.93 in) | 45 | 67.0 |
When to Specify 18 AWG × 3 Conductors (3-Wire RTD)
Standard industrial choice for process plant Pt100 / Pt1000 transmitters. The third lead allows the receiving transmitter bridge to measure and subtract average lead-wire resistance over medium-to-long plant runs while keeping cable outer diameter compact at 4.57 mm (0.180 in).
When to Specify 18 AWG × 4 Conductors (4-Wire RTD)
Recommended for Class A / 1/10 DIN high-accuracy temperature measurement, custody transfer, pharmaceutical autoclaves and calibration skids. Separate excitation and voltage-sense pairs completely eliminate lead-wire resistance error and contact resistance asymmetry.
Frequently Asked Questions (FAQ)
Why are nickel-plated copper conductors used instead of bare or tinned copper for 200 °C RTD cables?
Standard tin plating begins to oxidize and form intermetallic compounds above +150 °C, which increases conductor loop resistance and introduces drift into sensitive RTD resistance measurements. Nickel-plated copper remains chemically and electrically stable at continuous temperatures up to +200 °C (+392 °F) and beyond.
What is the purpose of the spiral-wrapped skived PTFE tape and drain wire?
The spiral skived PTFE separator tape binds the insulated cores into a uniform circular bundle, prevents jacket material from adhering to the cores during extrusion and allows clean stripping at sensor heads. The integral nickel-plated copper drain wire maintains continuous contact with the ~90% braid shield so technicians can ground the screen at the control cabinet without unbraiding fine shield wires.
What details should be included when requesting a quotation for 200 °C RTD sensor cable?
Specify whether your instrumentation loop requires 3 conductors (18 AWG × 3C) or 4 conductors (18 AWG × 4C), total footage or meterage, preferred spool/reel packaging and any custom core color-coding or outer jacket color requirements.
Need a Quotation or Custom Spool Length for 200 °C Shielded RTD Cable?
Share your 3-core or 4-core configuration, total route length and delivery destination with TEBAOFLEX engineering sales for factory-direct pricing, lead time and sample evaluation.
Explore All High-Temp & Specialty Cables
