The current version of the FT702 is Version 22. Its strength and dependability have made it particularly popular for wind turbine control. It is used globally by the world's leading wind turbine manufacturers, as well as in a range of meteorology applications.


Wind speed
Accuracy: ±0.5m/s (0-15m/s)
±4% (>15m/s)
Wind direction
±2° (within ±10° datum)
±4° (beyond ±10° datum)
Operating Temperature
-40to +85°C
Three heater elements ensure even distribution of heat over entire body. Passed US military icing tests to MIL-STD810G.
Power required
Min consumption - heaters off. Supply current is limited to 4A by default. Recognised component to UL 61010-1.




Patented Acu-Res technology gives 5 measurements per second.
Fully sealed and corrosion resistant to ISO 9227 & IEC12944. Corrosion class C5M.
Small, compact and easily transported. I/O connector either 5-way (RS485 option) or 8-way (4-20mA option) multipole connector.
Hard anodised alloy body for a lightweight yet rugged sensor that can withstand severe vibrations and extreme impacts.


The FT702 has two physical mounting options: The Flat Front (FF) for fitment to a bar and the Pipe Mount (PM) for fitment to a pipe with the use of an FT090 adaptor. Both of these models have been designed for wind turbine control and are widely used by the world's leading wind turbine manufacturers. The pipe mount system (PM) gives improved lightning and environmental protection as the communication and power cable is kept fully protected inside the pipe.

Mount to a flat bar
Improved lightning protection

Interface and Data Format

The FT702 V22 wind sensor comes with two output options, either digital or analogue.

The part number FT702LT is the digital variant with an RS-485 output. The interface can be used to request or obtain wind speed and direction readings. The communication link can also be used to configure or verify the sensor’s internal settings. The sensor sends and receives simple ASCII characters and can be set up to output a common NMEA 0183 MWV compatible sentence, so the sensor can be incorporated into marine navigation systems.

The part number FT702LT/D is the analogue variant with two 4-20 mA current loop outputs. Each output can be used to provide a measureable current that is proportional to wind speed and direction.

The wind speed measurement range for the FT702LT sensors is 0-50m/s. The scale of the wind speed output signal of the FT702LT/D can be adjusted to indicate a range from 0-30m/s to 0-70m/s. Output can be set to m/s, mph or knots.

The connector type used on the sensor is environmentally sealed and corrosion protected. The connectors can be sourced from either K.K Fischer or ODU providing a choice of supply options for cable assembly. The digital sensor has a 5-pin connector and the analogue variant has an 8-pin connector.

Technical Specification

Sensor performance

Measurement principle: Acoustic Resonance (automatically compensates for variations in temperature, pressure & humidity)

Units of measure: meters per second (m/s), kilometres per hour (kph), or knots

Altitude: 0-4000m operating range

Temperature range: -40° to +85°C (operating and storage)

Humidity: 0-100%

Ingress protection: IP67, EN 60529 (2000)

Heater settings: 0° to 55°C. The heater set point can be configured.

Power requirements

Supply voltage: 20V to 30V DC (24V DC nominal)

Supply current (heater off ): 30mA

Supply current (heater on): 4A (default), 0.1-6A (max) – Configurable in software. Heater power consumption will depend on the energy required to keep the sensor’s temperature at the user determined set point. The heater and sensor power consumption is limited by default to 99W.

Safety: Certified as Recognized Component to UL 61010-1 and CSA 22.2.61010-1-04 electrical safety standards


Sensor weight: 320g (max) for Flat Front variant, 350g (max) for Pipe Mount Variant

I/O connector: 5-way (RS485 option), 8-way (4-20mA option) multipole connector

Digital Sensor

FT702LT-V22-FF, FT702LT-V22-PM 

Interface: RS485, galvanically isolated from power supply lines and case

Format: ASCII data, polled or continuous output modes

Data update rate: 5 measurements per second

Analogue Sensor

FT702LT/D-V22-FF, FT702LT/D-V22-PM, FT702LT/D50-V22-FF, FT702LT/D50-V22-PM, FT702LT/D60-V22-FF, FT702LT/D60-V22-PM, FT702LT/D70-V22-FF, FT702LT/D70-V22-PM

Interface: 4-20mA, galvanically isolated from power supply lines and case

Format: One 4-20mA current loop for wind speed (different scaling factors are available). One 4-20mA current loop for wind direction (datum value configurable as 4mA or 12mA). Both analogue channels are updated 5 times per second.

4-20mA configuration port: This port is for the user to change the internal settings of analogue sensors and to perform diagnostic testing. This interface is not intended for permanent connection to the turbine controller, data logger or other device.

Heating System

The sensor is fitted with a thermostatically controlled ‘all-body’ heating system. The sensor maintains its temperature at a user specified heater set point of between 0⁰C and 55⁰C. Three software controlled heaters are used to distribute heat intelligently over the entire sensor.

In standard format the heaters draw a maximum of 99W. For extreme environments the current limit can be adjusted (power supply and cabling permitting) from 0.1 to 6 Amps. The sensor’s small size means that the power is used very effectively ensuring that the sensor can stay ice-free. The heaters can also be switched off and then current draw falls to 25mA.


The FT702 ultrasonic sensor has passed over 28 certification tests, making it ideal for use in extreme climates. Theses tests include:

  • Hail EN 61215
  • Corrosion ISO 9227 (2006)
  • Neutral Salt Spray IEC 12944 C5-M
  • High Sinusoidal and Random Vibration EN 60068-2-6 and EN 60068-2-64
  • Drop EN 60068-2-31
  • Sand & Dust, Fog & Rain DEF STAN 00-35 CL25, CL26, CL27
  • Ingress Protection IP67
  • Ice MIL-STD-810G, Method 521.3 Icing/Freezing Rain, Procedure – Ice Accretion.

For full details see Product Certification.

Download Environmental Safety Sheet for the FT702

In addition the FT702LT-V22 sensor is a Recognized Component by Intertek to the UL safety standard 61010-1 and CAN/CSAC22.2 No. 61010-1-04.

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