RTD-Hazardous

Supported Applications

The ACI Platinum RTD Hazardous Housing series provides single-point temperature sensing for commercial and industrial heating and cooling building management systems. Designed specifically for hazardous atmospheres, these sensors are engineered for use in environments requiring explosion-proof or dust-ignition proof protection. Documented applications include process control, exhaust systems, and general industrial sensor applications where Class I, II, and III hazardous location ratings are required.

Operating Conditions & Performance

The series utilizes Platinum RTD sensors with a measurement range of -40 to 200°C (-40 to 392°F). Sensor accuracy is specified as Class A (±/− 0.06%), defined by the tolerance formula: ±/− °C = (0.15 °C + (0.002 * |t|)), where |t| is the absolute value of temperature above or below 0°C in °C. Specific accuracy points include ±/− 0.23°C (±/− 0.414°F) at -40°C (-40°F), ±/− 0.15°C (±/− 0.27°F) at 0°C (32°F), and ±/− 0.55°C (±/− 1.00°F) at 200°C (392°F). The sensors exhibit a nominal response time of 8 seconds for a 63% step change.

Enclosures are rated for an ambient operating temperature range of -50 to 60°C (-58 to 140°F) and storage temperatures from -40 to 85 °C (-40 to 185 °F). The series supports humidity levels of 10 to 95% RH, non-condensing. Electrical connections utilize 22 AWG Etched Teflon colored lead wires with silver-plated copper conductors.

Hazardous Location Ratings

The connection heads meet the following enclosure ratings:

• Explosion Proof: CL. I, Div. 1 & 2, Groups A, B, C, D
• Dust-Ignition Proof: CL. II, Div. 1, Groups E, F, G
• Raintight: CL. II, Div. 2, Groups F, G
• Wet Locations: CL. III

Certifications include UL 1203 and CSA C22.2 No. 30. The enclosures carry NEMA ratings of 3, 4, 7ABCD, and 9EFG.

Configuration Options

The series is available in three primary configurations: Room (Wall Mounted), Duct, and Immersion. Each configuration supports specific process connections, insertion lengths, and housing materials to accommodate diverse installation requirements while maintaining hazardous location compliance.

Sensor Elements & Outputs

• Model Series: A/100 (100 Ω nominal) or A/1K (1 KΩ nominal).
• Wire Configuration: Two-wire (non-polarity sensitive) or three-wire (polarity sensitive).
• Sensor Curve: PTC (Positive Temperature Coefficient), DIN EN 60751 (IEC 751), with a temperature coefficient of 3850 ppm / °C.

Housing & Process Connections

• Room Configuration (-R): Features a Copper-Free Aluminum enclosure. Includes two ½" NPT female hubs for conduit connections.
• Duct Configuration (-D): Utilizes a Feraloy® Iron Alloy connection head with probe lengths of 4", 8", 12", or 18". The process thread is ½" NPT (National Pipe Tapered).
• Immersion Configuration:
  • -I: Includes a welded thermowell made of 304 Stainless Steel with insertion lengths of 2.5", 4", or 6".
  • -INW: Immersion without a welded thermowell, designed for use in existing thermowells (bore diameter 0.260").
• Probe Material: 304 Stainless Steel with a probe diameter of 0.250" (6.35mm).

Options & Accessories

• NIST Certificate available for calibration verification.
• Thermowells are offered separately for higher flow rates, temperatures, pressure ratings, or corrosion resistance requirements.
• Lead wire lengths of 14" (35.6 cm) or 24" (61 cm).

Key Product Differences

The series distinguishes between Room, Duct, and Immersion models based on the enclosure material and probe geometry. The "-R" configuration uses a Copper-Free Aluminum housing optimized for wall mounting in rooms. In contrast, "-D" (Duct) and "-I/-INW" (Immersion) configurations utilize Feraloy® Iron Alloy connection heads to withstand duct or process line conditions.

Within the Immersion category, the "-I" variant includes a factory-welded 304 Stainless Steel thermowell with specific insertion lengths (2.5", 4", 6"). The "-INW" variant omits the welded well, allowing installation into existing field-installed thermowells that meet the specified bore diameter of 0.260" and thread requirements.

Model numbers further differentiate between sensor resistance (100 Ω vs. 1 KΩ) and wiring configuration (Two-Wire vs. Three-Wire). The "EXPL" suffix denotes the hazardous location rating inherent to this series, while an optional "NIST" designation indicates a three-point NIST certificate is included.