Integrated Transmitter Series
Explosion-Proof TC/RTD with Transmitter
Integrated explosion-proof thermocouple and RTD with built-in 4-20mA temperature transmitter. NEPSI certified for hazardous areas (Ex d IIB T4 / IIC T5 / T6, Ex ia IIC T6). Supports Pt100, Cu50/Cu100 RTD and Type K, N, E, J, T thermocouples with 0.1~0.5 grade precision. IP65 rated, 24V DC powered, ideal for petrochemical, refining, and offshore applications.
Product Overview
Hazardous-area selection tip: Explosion-proof certification is one part of the spec. Read how to choose the right industrial temperature sensor for guidance on matching sensing element with assembly and approval class.
The Explosion-Proof TC/RTD with Transmitter is an integrated temperature measurement instrument that combines an explosion-proof thermocouple or thermal resistance sensor element with a built-in 4-20mA temperature transmitter inside a single flameproof enclosure. This design eliminates the need for separate transmitter housings and simplifies field wiring, reducing installation costs and potential failure points in hazardous area applications.
The transmitter module converts the thermocouple millivolt signal or RTD resistance change into a linearized, standardized 4-20mA current output that can be transmitted over long cable runs without signal degradation. Available in precision grades of 0.1, 0.2, and 0.5, the integrated transmitter provides reliable two-wire operation from a 24V DC supply with a maximum load resistance of 250Ω. The unit supports thermocouple types K, N, E, J, and T as well as Pt100, Cu50, and Cu100 RTD elements.
Certified by NEPSI with multiple explosion-proof grades including Ex d IIB T4, Ex d IIC T5, Ex d IIC T6, and Ex ia IIC T6, this instrument is approved for deployment in Zone 1 and Zone 2 hazardous areas found in petroleum refining, chemical processing, offshore platforms, pharmaceutical plants, and other industries where flammable gases or vapors may be present. The IP65-rated enclosure provides robust protection against dust and water jets, while insulation resistance exceeds 50MΩ at ambient conditions.
Multiple mounting configurations are available including fixed screw thread types (-240 series with M27×2 or G3/4 process connections) and fixed flange types (-440/-441 series). Probe diameters of Φ16mm and Φ12mm accommodate various process vessel penetrations, with insertion lengths from 300mm to 2150mm. Optional analog (M) or digital (S) display heads provide local temperature indication.
Technical Specifications
Thermocouple Specifications
| TC Type | Index | Range | Tolerance Class I | Tolerance Class II |
|---|---|---|---|---|
| K (WRN-B) | Nickel-Chromium / Nickel-Silicon | 0 ~ 1300°C | ±1.5°C or ±0.004|t| | ±2.5°C or ±0.0075|t| |
| N (WRM-B) | Nicrosil / Nisil | 0 ~ 1300°C | ±1.5°C or ±0.004|t| | ±2.5°C or ±0.0075|t| |
| E (WRE-B) | Nickel-Chromium / Constantan | 0 ~ 800°C | ±1.5°C or ±0.004|t| | ±2.5°C or ±0.0075|t| |
| J (WRF-B) | Iron / Constantan | 0 ~ 750°C | ±1.5°C or ±0.004|t| | ±2.5°C or ±0.0075|t| |
| T (WRC-B) | Copper / Constantan | -40 ~ 350°C | ±0.5°C or ±0.004|t| | ±1.0°C or ±0.0075|t| |
RTD Specifications
| RTD Type | Index | Range | Tolerance Class A | Tolerance Class B |
|---|---|---|---|---|
| Pt100 (WZPB) | Platinum RTD | -200 ~ +500°C | ±(0.15+0.002|t|)°C | ±(0.30+0.005|t|)°C |
| Cu50 (WZCB) | Copper RTD | -50 ~ +100°C | — | ±(0.30+0.006|t|)°C |
| Cu100 (WZCB) | Copper RTD | -50 ~ +100°C | — | ±(0.30+0.006|t|)°C |
Transmitter Output & General Specifications
| Parameter | Specification |
|---|---|
| Output Signal | 4-20mA (two-wire) |
| Supply Voltage | 24V DC ±10% |
| Load Resistance | ≤ 250Ω |
| Transmitter Precision | 0.1 / 0.2 / 0.5 grade |
| Protection Rating | IP65 |
| Insulation Resistance | ≥ 50MΩ (at ambient) |
| Explosion-Proof Grade | Ex d IIB T4 / Ex d IIC T5 / Ex d IIC T6 / Ex ia IIC T6 |
| Probe Diameter | Φ16mm / Φ12mm |
| Insertion Length (L) | 300 ~ 2150mm |
| Process Connection | M27×2, G3/4 (thread); DN50~DN150 (flange) |
| Display Options | Analog pointer (M) / Digital LCD (S) |
| Applicable Standards | IEC 60584 (TC), IEC 60751 (RTD), GB/T 26786-2011, JB/T 7391-1994 |
NEPSI Explosion-Proof Certifications
| Certificate No. | Ex-Proof Type | Applicable Models |
|---|---|---|
| GYB97151 | Ex d IIB T4 | Thermocouples (WRN-B, WRE-B, WRF-B, WRC-B) |
| GYB97152 | Ex d IIB T4 | Thermal Resistance (WZPB, WZCB) |
| GYB02475 | Ex d IIC T5 | Thermocouples |
| GYB02476 | Ex d IIC T5 | Thermal Resistance |
| GYB05363X | Ex d IIC T6 / Ex ia IIC T6 | Thermocouples |
| GYB05364X | Ex d IIC T6 / Ex ia IIC T6 | Thermal Resistance |
Key Features
Integrated 4-20mA Transmitter
Built-in temperature transmitter converts sensor signals to a linearized 4-20mA current loop output, eliminating external transmitter modules and reducing installation complexity.
NEPSI Explosion-Proof Certified
Multiple NEPSI certifications covering Ex d IIB T4, Ex d IIC T5, Ex d IIC T6, and Ex ia IIC T6 classifications, approved for Zone 1 and Zone 2 hazardous areas.
High Precision Grades
Available in 0.1, 0.2, and 0.5 precision grades, meeting the demands of critical process control applications where measurement accuracy is paramount.
Versatile Sensor Options
Supports 5 thermocouple types (K, N, E, J, T) and 3 RTD types (Pt100, Cu50, Cu100), covering measurement ranges from -200°C to +1300°C for diverse applications.
IP65 Industrial Protection
Robust IP65-rated enclosure with insulation resistance ≥50MΩ, designed for harsh outdoor and industrial environments including dust, moisture, and water jets.
Local Display Options
Optional analog pointer (M type) or digital LCD (S type) display heads provide on-site temperature readout without additional instrumentation or handheld devices.
Applications
Petroleum Refining
Monitor reactor temperatures, distillation column profiles, and heat exchanger performance in refineries where flammable hydrocarbon vapors require explosion-proof instrumentation.
Chemical Processing
Integrated transmitter output simplifies DCS/PLC integration for reaction vessel temperature control, solvent recovery systems, and exothermic process monitoring.
Offshore Oil & Gas
IP65-rated and NEPSI-certified units withstand marine environments on offshore platforms, FPSOs, and subsea processing facilities with reliable 4-20mA signal transmission.
Pharmaceutical & Biotech
High-precision 0.1 grade transmitters provide accurate temperature data for reactor vessels, autoclaves, and sterile processing environments requiring tight temperature control.
Power Generation
Monitor boiler, turbine, and flue gas temperatures in power plants. Two-wire 4-20mA output enables long cable runs to centralized control rooms without signal loss.
Food & Beverage
Pt100 RTD with integrated transmitter delivers precise temperature measurement for pasteurization, fermentation, and CIP cleaning processes in food-grade facilities.
Model Selection & Ordering Guide
Model Naming Convention
The model code follows a standardized naming system: W-[Category]-[Element]-B-J-[Fixation]-4-[Diameter]-[Display]-[Additional]. The “B” suffix indicates explosion-proof construction, “J” indicates integrated connection head, and “4” indicates built-in 4-20mA transmitter output.
| Position | Code | Meaning |
|---|---|---|
| W | W | Temperature instrument prefix |
| Category | R = TC, Z = RTD | Sensor category |
| Element | N(K), M(N), E(E), F(J), C(T) / P(Pt), C(Cu) | Sensing element type |
| B | B | Explosion-proof construction |
| J | J | Integrated connection head |
| Fixation | 230/240/440/441… | Mounting type (thread/flange) |
| 4 | 4 | Built-in transmitter (4-20mA) |
| Diameter | 16 or 12 | Probe diameter (Φmm) |
| Display | S (digital) / M (analog) | Local display type |
Fixed Screw Thread Type (-240 Series)
| TC Type | Model (TC) | RTD Type | Model (RTD) | d (mm) | L (mm) |
|---|---|---|---|---|---|
| K | WRN-BJ-240-4 | Pt100 | WZPB-BJ-240-4 | Φ16/Φ12 | 300~2150 |
| N | WRM-BJ-240-4 | Cu50 | WZCB-BJ-240-4 | Φ16/Φ12 | 300~2150 |
| E | WRE-BJ-240-4 | Cu100 | WZCB-BJ-240-4 | Φ16/Φ12 | 300~2150 |
| J | WRF-BJ-240-4 | — | Φ16/Φ12 | 300~2150 | |
| T | WRC-BJ-240-4 | — | Φ16/Φ12 | 300~2150 | |
Thread specifications: M27×2 (standard), G3/4 (optional). Display heads: Digital LCD (S) or Analog pointer (M).
Fixed Flange Type (-440/-441 Series)
| TC Type | Model (TC) | RTD Type | Model (RTD) | d (mm) | L (mm) |
|---|---|---|---|---|---|
| K | WRN-BJ-440-4 | Pt100 | WZPB-BJ-440-4 | Φ16/Φ12 | 300~2150 |
| N | WRM-BJ-440-4 | Cu50 | WZCB-BJ-440-4 | Φ16/Φ12 | 300~2150 |
| E | WRE-BJ-440-4 | Cu100 | WZCB-BJ-440-4 | Φ16/Φ12 | 300~2150 |
| J | WRF-BJ-440-4 | — | Φ16/Φ12 | 300~2150 | |
| T | WRC-BJ-440-4 | — | Φ16/Φ12 | 300~2150 | |
Flange specifications: DN50~DN150 (PN0.6~6.3MPa). Available in RF (raised face) and FF (flat face) types.
Frequently Asked Questions
Need an Explosion-Proof Temperature Transmitter Solution?
Our engineering team can help you select the right thermocouple or RTD type, explosion-proof grade, mounting configuration, and transmitter precision for your specific process requirements. Whether you need a single unit or bulk quantities for a plant-wide installation, we provide technical support from specification to commissioning.
Our engineers typically respond within 12 business hours with detailed technical specifications and pricing.