GreenFlow GF Series
Thermal Dispersion Airflow/Temperature Measurement Probe for Outdoor Intakes, Plenums and Fan Cabinets


GreenFlow GF Series
Thermal Dispersion Airflow/Temperature Measurement Probe for Outdoor Intakes, Plenums and Fan Cabinets

The IAT-US integrated probe is compatible with GF Series remote transmitters and various GreenTrol application specific controllers.  The probe is designed for insertion into outdoor air intakes, plenums or other air paths and is available with a 3, 10, 25 or 50 foot plenum rated cable with connector plug. Available in aluminum only.  Universal, adjustable length tube can be rotated on its mounting bracket.  Probes are available in 6, 8 and 16 inch lengths.  Applicable for outdoor air intakes, plenums or other openings up to 8 sq ft.

Rooftop air handler outdoor air intakes

Fan cabinets and powered exhaust boxes

Unit ventilator outdoor air intakes

ERV cabinet and wheel intake/exhaust paths


Compatible with GreenTrol transmitters and controllers that accept IAT integrated sensors

Thermal dispersion technology

Calibrated from 0 to 3,000 FPM

Stable bead-in-glass thermistor sensors

NIST traceable airflow and temperature measurement

Accurate and repeatable

Designed for openings up to 8 square feet

Universal mounting design facilitates ordering and installation

Three probe lengths available

Aluminum probe construction

FEP plenum rated cable with terminal DIN connector plug provided


IAT (integrated airflow/temperature) sensors reduce cost by eliminating the redundancy of a separate transmitter for airflow and temperature measurement.  The processing circuitry and firmware is integrated into one of GreenTrol’s microprocessor-based transmitters or application specific controllers.

The IAT-US airflow/temperature sensor is designed for mounting inside of plenums or other openings where airflow measurement is desired.  One or two probes with a single sensor node are typically used.  Sensor node airflow accuracy is ±3% of reading to NIST traceable standards. An installed accuracy of ±10% of reading or better can often be achieved without field adjustment. A field adjust wizard built into GreenTrol’s transmitters and application specific controllers facilitate field setup when conditions warrant.

The IAT-US sensor probe uses the principal of thermal dispersion to determine the airflow rate.  Thermal dispersion is ideal for HVAC applications that typically require measurement of low air velocities.  Each sensing node uses two thermistors to determine airflow. One thermistor is self-heated above ambient while a second thermistor determines the ambient air temperature.  The power dissipated into the airstream is directly related to the airflow rate.

Each thermistor body is a hermetically sealed bead-in-glass probe.  Bead-in-glass thermistors have demonstrated extreme stability and superior performance over chip type thermistors used by other manufacturers.  The bead-in-glass sensor used has been time tested for over 35 years by GreenTrol’s sister company, EBTRON.  Thermistors are potted in a waterproof sensor assembly and are designed for years of trouble-free operation.

Each sensing node is individually calibrated at 7 points in high performance wind tunnels. Transmitters and controllers
measure and process each individual sensor node independently. The result is the true average airflow rate and temperature when more than one sensing node is applied.


Airflow Measurement: Provides individual sensor node airflow rates to compatible GreenTrol transmitters and controllers

Temperature Measurement: Provides individual sensor node temperatures to compatible GreenTrol transmitters and controllers

Airflow/Temperature Measurement Probe

Type: -US Universal Insertion Mount Thermal Dispersion Airflow and Temperature Measurement Probe

Available Configurations 

Single: 1 probe x 1 sensor node

Dual: 2 probes x 1 sensor node/probe

Sensing Node Sensors

Self-heated sensor: Precision, hermetically sealed, bead-in-glass thermistor probe

Temperature sensor: Precision, hermetically sealed, bead-in-glass thermistor probe

Probe Tube

Material: Mill finish 6063 aluminum

Probe Mounting Brackets

Material: 304 stainless steel

Probe Length: 6, 8 or 16 in. [152.4, 203.2 or 406.4 mm] (adjustable)

Sensing Node Housing

Material: Glass-filled Polypropylene

Sensor Potting Materials: Waterproof marine epoxy

Sensing Node Internal Wiring 

Sensing Node Internal Wiring: Kynar® coated copper

Probe to Transmitter Cables 

Material:  FEP jacket, plenum rated CMP/CL2P, UL/cUL listed, -67 to 392 ⁰F [-55 to 200 ⁰C], UV tolerant

Standard Lengths:  10, 25 and 50 ft. [3.1, 7.6 and 15.2 m]

Connecting Plug:  0.60” [15.24 mm] nominal diameter

Airflow Measurement 

Sensor Accuracy:  ±3% of reading to NIST-traceable airflow standards

Averaging Method:  Independent, arithmetic average

Installed Accuracy:  Typically better than ±10% of reading in ducts/openings ≤ 8 sq ft [0.74 sq m]

Calibrated Range:  0 to 2,000 fpm [0 to 10.16 m/s]

Calibration Points:  7

Temperature Measurement 

Averaging Method:  Independent, velocity weighted

Accuracy:  ±0.15⁰F [0.08 ⁰C]

Environmental Limits, Power Requirements & Dimensions

Environmental Limits

Temperature: -20 to 120 ⁰F [-28.9 to 48.9 ⁰C]

Note: Temperature limits for operation may be limited by the transmitter or controller selected

Humidity: 0 to 100%

Power Requirement: Power is provided by the transmitter or controller and is included in the transmitter/controller power requirement specification

Related Documents

GreenTrol Automation

156 Holly View Lane Loris, SC 29569 Toll Free 877 446 8765

Find a Rep Near YouCancel
Rep Finder

Select Your Country/Region

Enter your Zip Code