RTD-Rigid-Ave

Supported Applications

The ACI Rigid Averaging Series temperature sensors are designed for use with electronic controllers in commercial heating and cooling building management systems. These rigid averaging probes provide a better average temperature reading over the length of the duct compared to single-point sensors by utilizing either a continuous sensing element (Platinum) or four evenly spaced sensing points (Thermistor, Balco, Nickel). The series is specifically designed for duct mounting.

Operating Conditions & Performance

The measurement range varies by enclosure type and sensor configuration. Storage temperature ranges from -40 to 80 °C (-40 to 185 °F), while operating humidity is rated at 10 to 95% RH, non-condensing.

• Platinum RTD Accuracy: ±/− 0.06% Class A (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 points include ±/− 0.23°C (+/−0.414°F) @ -40 °C (-40 °F), ±/− 0.15 °C (+/− 0.27 °F) @ 0 °C (32 °F), and ±/− 0.38 °C (+/− 0.69 °F) @ 115 °C (239 °F).
• Thermistor Accuracy: A/1.8K Series: ±/− 0.5 °C @ 25 °C (77 °F) and (±/−1.0 °C) (±/−1.8 °F); A/10K-E1 Series: ±/− 0.3 °C (±/− 0.54 °F); All Else: ±/− 0.2 °C (±/− 0.36 °F).
• Balco Accuracy: ±/− 1% @ 21.1 °C (70 °F).
• Nickel Accuracy: Ranges from ±/− 1.52 °C (+/− 2.73 °F) @ -40 °C (-40 °F) to ±/− 1.25 °C (2.25 °F) @ 121 °C (250 °F).

Enclosures support specific ambient temperature limits: Galvanized Steel and Aluminum enclosures operate from -40 to 115 °C (-40 to 239 °F); ABS Plastic operates from -30 to 90 °C (-22 to 194 °F); Polystyrene Plastic operates from -40 to 70°C (-40 to 158°F).

Configuration Options

The series offers configurable options for sensor elements, output wiring, enclosure materials, and lengths. The probe features a 304 Stainless Steel sheath with a diameter of 0.250" (6.35 mm) and uses 22 AWG (0.65 mm) wire.

Sensor Elements & Outputs

• Platinum RTD: Continuous sensing element; available as A/100 (100 Ω nominal @ 0 °C) or A/1K (1 KΩ nominal @ 0 °C).
• Thermistor: Four evenly spaced points. Options include A/1.8K, A/3K, A/AN (Type III), A/AN-BC, A/CP (Type III), A/50K, A/CSI, A/10KS, A/10K-E1, A/20K, and A/100KS with nominal resistances ranging from 1.8 KΩ to 100 KΩ @ 25 °C (77 °F).
• Balco: Four evenly spaced points; 1 KΩ nominal @ 21.1 °C (70 °F).
• Nickel: Four evenly spaced points; 1 KΩ nominal @ 21.1 °C (70 °F).
• Output Configuration: Available as 2-Wire or 3-Wire RTD configurations.

Housing & Enclosures

• -GD Galvanized Steel: NEMA 1 (IP10) rating; -40 to 115 °C (-40 to 239 °F).
• -PB ABS Plastic: Plenum Rated, UL94-HB; -30 to 90 °C (-22 to 194 °F); dimensions: 4.79" (121.55 mm) height x 3.60" (91.44 mm) width x 2.35" (59.80 mm) depth.
• -BB Aluminum: NEMA 3R (IP 14); -40 to 115 °C (-40 to 239 °F).
• -4X Polystyrene Plastic: NEMA 4X (IP 66), UL94-V2; -40 to 70°C (-40 to 158°F); dimensions: 3.70" (93.960 mm) height x 3.88" (98.60 mm) width x 2.19" (55.69 mm) depth.

Installation & Wiring

The probe is installed by drilling a 3/8" hole in the duct and inserting it until the foam pad is tight to the duct. Electrical connections are made via 2 or 3 flying lead wires using wire nuts, terminal blocks, or crimp style connectors.

Key Product Differences

Variants differ by sensor element type (Platinum RTD vs. Thermistor/Balco/Nickel), output wiring configuration (2-Wire vs. 3-Wire for Platinum models shown in variants), enclosure material and rating, and probe length.

• Lengths: Available in 12", 18", 24", and 36" configurations as indicated by the model number suffix (e.g., -12").
• NIST Calibration: Specific variants include a "-NIST" designation, indicating NIST-traceable calibration options.
• Sensor Output Codes: Model numbers reflect specific sensor types such as A/1K (Platinum 1 KΩ), while the broader series supports Thermistor codes like A/AN or Balco/Nickel configurations not explicitly listed in every SKU but documented for the family.