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Nickel-Flexible-Ave
Nickel Flexible Averaging
- The flexible averaging sensor measures across multiple points to produce a better duct air average than a single-point duct sensor.
- The product uses a 1K ohm platinum RTD with Class A tolerance, DIN EN 60751 reference, and a 3850 ppm per deg C temperature coefficient.
- The A/1K-2W-FA series is listed as two-wire and non-polarity-sensitive, with controller wiring connected to analog input leads.
- The flexible sensor uses low-smoke PVC cable rated CL2P or CMP, with a 0.170 in nominal cable diameter and dual-wall adhesive heat shrink at sensing elements.
- Ordering supports galvanized, plastic, aluminum bell box, and NEMA 4X enclosure options for different mounting and protection needs.
- Flexible averaging is limited to 0 to 75 deg C operation, 10 to 90% non-condensing humidity, and applications that do not require UV, chemical, or high-humidity resistance.
- Use the sensor across large air-handler duct sections where stratification makes a single-point reading less representative.
- Use flexible averaging in rooftop HVAC ductwork when the operating temperature and humidity stay inside the flexible sensor limits.
- Use a crisscross duct pattern to average mixed air streams and reduce error from hot and cold layers.
- Place the averaging element downstream of fan discharge where the airstream is more uniform across the duct cross-section.
- Use the sensor where return duct temperature needs a broad representative average instead of a local point sample.
- Applications where averaged air temperature feedback can support tighter HVAC control.
Product Overview
- Accuracy 70ºF (21.1ºC) : +/- 1%
- Alloy Material (-) Copper
- Alloy Material (+) Copper
- Applications Air and HVAC, Building and Maintenance, Medical
- Approvals Din 43760
- Cable Diameter 0.17 in
- Cable Material PVC
- Electrical Connection Pigtail Leads
- Enclosure Ratings NEMA Type 4X
- Fitting Polyamide 66 (High Performance Nylon)
- Insulation Etched Teflon (PTFE) Colored Leads
- Insulation Color Red
- Operating Current 5 mA
- Operating Humidity 10 to 95% RH, non-condensing
- Operating Temperature, Max 250 °C
- Operating Temperature, Min -40 °C
- Output Detail 1000 Ohms nominal
- Response Time 15 Seconds nominal
- Self Heating Effect 0.3 °C / mW
- Series ID Nickel-Flexible-Ave
- Sheath Material 304 Stainless Steel
- Stability +/- 0.05% after 1000 Hours @ 150ºC (302ºF)
- Storage Temperature, Max 75 °C
- Storage Temperature, Min -20 °C
- Temperature Measurement Range -40 to 250°C
- Temperature Sensor Type 1K Ohm Nickel RTD
- Tube Length 4.5 in
- Wire Gauge 22 AWG
Supported Applications
The ACI Nickel Flexible Averaging Series is a multi-point temperature sensor designed for use with electronic controllers in commercial heating and cooling building management systems. The series provides an average temperature reading of air inside ducts, offering improved accuracy compared to single-point sensors. Documented applications include Air Handlers, Roof Top Units, Mixed Air/Discharge/Supply Air Temperature Monitoring, Data Centers, and Hospitals.
Installation requires the entire length of the sensor coil to be placed completely inside the duct with no part exposed to exterior air. When installing near air-handling units, place the sensor downstream from the fan discharge. The flexible averaging sensors are limited to applications where operating temperatures do not exceed 0 to 75°C (32 to 158°F) and where high humidity, chemical resistance, or UV Light Air Treatment Systems are not required; Copper Averaging must be used if UV lights are installed in the duct.
Operating Conditions & Performance
The series utilizes a Nickel RTD (PTC - Positive Temperature Coefficient) sensor element conforming to Din 43760 with a temperature coefficient of 6370 ppm/°C. The operating and storage temperature range is 0 to 75°C (32 to 158°F), while the storage temperature range extends from -20 to 75°C (-4 to 167°F). Operating humidity must remain between 10 to 90% RH, non-condensing.
Accuracy varies by sensor length and test temperature:
- 8' and 12' Lengths: +/- 0.23°C (+/- 0.40°F) @ 21.1°C (70°F); +/- 1.59°C (+/- 1.06°F) @ 54.4°C (130°F)
- 24' and 50' Lengths: +/- 0.24°C (+/- 0.42°F) @ 21.1°C (70°F); +/- 0.61°C (+/- 1.09°F) @ 54.4°C (130°F)
Additional performance specifications include a response time of 15 Seconds nominal for a 63% step change, sensor stability of +/- 0.05% after 1000 Hours @ 150°C (302°F), and self-heating of 0.3°C/mW in still air with a maximum operating current of 5 mA.
Configuration Options
The series is configured as an averaging sensor with sensing points determined by the probe length: four sensing points for 8' and 12' lengths, and nine sensing points for 24' and 50' lengths. The flexible plenum-rated cable features a Low Smoke PVC jacket (CL2P or CMP Plenum Rated Cable) with a nominal diameter of 0.170" (4.32mm). Electrical connections consist of an 18 AWG sensing element with two 12 inch 22 AWG Etched Teflon colored lead wires.
Available enclosure options include:
- -GD Enclosure: Galvanized Steel, NEMA 1 (IP10)
- -PB Enclosure: ABS Plastic, UL94-HB, Plenum Rated
- -BB Enclosure: Aluminum, NEMA 3R (IP 14)
- -4X Enclosure: Polystyrene Plastic, UL94-V2, NEMA 4X (IP 66)
The sensor output is 1000 Ohms nominal with Red/Red lead wire colors. Optional accessories include copper capillary mounting clips and universal plastic mounting clips.
Key Product Differences
Variants within the Nickel Flexible Averaging series are distinguished by probe length (8', 12', 24', or 50') and enclosure type (-GD, -PB, -BB, or -4X). The model number structure follows the format A/1K-NI-FA-[Length]-[Enclosure], with an optional NIST Certificate suffix. For example, a 12-foot sensor in a Galvanized enclosure is designated as A/1K-NI-FA-12'-GD.
While the broader ACI Averaging Series includes Copper and other thermistor options (A/1.8K, A/3K, Platinum), this specific series code covers only the Nickel RTD Flexible configuration with 1 KΩ nominal output at 21.1°C (70°F). The flexible variant is distinct from copper tubing sensors in material composition (Low Smoke PVC vs. Copper) and application constraints regarding UV exposure.
PDFs & Manuals
