Ice arrives when the data matters
Wind measurement in freezing weather depends on preventing ice from interrupting the sensor’s measurement. Gill offers heated ultrasonic anemometers designed for cold and exposed environments, including WindObserver, WindSonic M and WindUltra models. Heating helps maintain measurement, but increases power demand, so sensor selection must account for icing severity, site conditions and available power.
How do you keep a wind sensor working in icing conditions?
A wind sensor keeps working in icing conditions when heating keeps its critical surfaces clear. Ice can stop a cup anemometer’s rotor or block an ultrasonic sensor’s acoustic path, and removing moving parts does not make a sensor immune to icing. How much heating is needed depends on how severe the icing is, the temperature and the power available.
Freezing fog, rime and freezing rain can affect wind sensors at airports, wind turbines, coastal masts and other exposed sites. Ice changes the shape of the sensor and can interfere with the measurement itself. On a conventional cup anemometer, ice can prevent the rotor from turning. On an ultrasonic sensor, ice can obstruct the acoustic path between transducers.
Ultrasonic technology removes moving parts, but it does not make a sensor immune to icing. Heating helps keep critical surfaces clear so that wind measurement can continue in freezing conditions.
The appropriate solution depends on the type and severity of icing, ambient temperature, wind exposure and the power available to operate the heater.
Requirements for wind measurement in icing conditions
Ice protection
Ice on the sensor head or transducers can interrupt ultrasonic measurement. Heated models are designed to reduce this risk, although severe conditions can still cause interruptions.
Heater power consumption
Heating can consume substantially more power than the sensor itself. This is particularly important for remote installations powered by solar panels or batteries.
For example, WindObserver 70 heating can draw up to 7 A at 24 V. The actual requirement depends on the model and configuration.
Type of heating
Heating arrangements differ across the range. Some models use heating designed to protect the sensor head, while MaxiMet uses transducer-only heating of approximately 7 W. Transducer-only heating may suit mild frost but should not be treated as equivalent to full heating for severe icing.
Unheated models
Some Gill instruments are not heated, including WindSonic 60, WindSonic 75, MetConnect One and WindObserver IS. Their suitability depends on the expected icing conditions and the consequences of losing measurement.
Comparing heated wind sensors
Heating options vary by model. The selection should balance the expected icing severity, operating temperature, wind exposure and available power.
| Consideration |  WindObserver 65, 70, 75, 90 and II |  WindSonic M |  WindUltra |  MaxiMet with heating |
|---|---|---|---|---|
| Heating | Heated anti-icing options | Heated | Integral heating | Transducer-only heating |
| Operating temperature | −55 to +70°C with heating | −40 to +70°C | −40 to +70°C | See datasheet |
| Icing information | Tested to MIL-STD-810F | See datasheet | See datasheet | Not intended for severe icing |
| Typical consideration | Severe cold and exposed sites | Cold sites needing a heated two-axis sensor | Compact or mobile platforms | Mild frost on compact weather stations |
| Power requirement | Model-specific; can be substantial | See datasheet | See datasheet | Approximately 7 W for transducer heating |
Heating helps maintain measurement in icing conditions, but does not guarantee uninterrupted operation in every environment. Confirm the exact model specification and heating arrangement before making a selection.
System specification
Icing severity and site exposure
Consider whether the site experiences freezing fog, rime, freezing rain or a combination of conditions. Temperature alone is not enough to establish the required heating. Wind exposure and the rate at which ice can accumulate also matter.
Heating current and power supply
Check the heater’s current demand at the intended supply voltage, rather than using the sensor’s basic power consumption as the system requirement. Allow for the heater’s demand when sizing a solar, battery or other remote power system.
These figures illustrate why model-level checks matter: WindObserver 65 heating is specified at 3 A at 24 V, while WindObserver 70 can draw up to 7 A at 24 V. Confirm the requirements for the exact model and configuration.
Operating temperature
Check the specified operating range with heating, where applicable. WindObserver models have an operating range of −55 to +70°C with heating, while WindSonic M and WindUltra are specified from −40 to +70°C.
Installation and maintenance
The sensor’s mounting position, exposure, accessibility and power arrangements should be considered together. For hazardous-area installations, note that WindObserver IS is unheated, so icing risk must be assessed as part of the site specification.
Gill heated wind sensors
The appropriate sensor depends on the required wind measurement, icing conditions, installation constraints and power budget.
WindObserver
Heated stainless-steel ultrasonic anemometer
WindObserver heated models include WindObserver 65, 70, 75, 90 and II. The range is icing tested to MIL-STD-810F and operates from −55 to +70°C with heating.
Heater requirements vary by model, so confirm the correct figures before sizing the power supply.
WindSonic M
Heated two-axis ultrasonic anemometer
WindSonic M is the heated version of the WindSonic sensor, with a hard-anodised aluminium construction for cold and demanding sites.
Confirm the heating power and interface requirements against the current datasheet.
WindUltra
Compact ultrasonic anemometer with integral heating
WindUltra has integral heating and a compact design suited to mobile and exposed platforms.
Confirm the power demand and environmental suitability for the intended installation.
MaxiMet with heating
Compact weather station with transducer heating
The heated MaxiMet option uses transducer-only heating of approximately 7 W. This may be suitable where mild frost is the main concern, but it is not recommended for severe icing.
Check the specific MaxiMet model’s operating range and heating specification before selecting it for a cold-weather installation.
insight
Heater sizing
Ice forms when supercooled droplets freeze on contact with exposed surfaces or when freezing rain coats the sensor. The rate of ice accumulation depends on factors including temperature, droplet size, wind speed and exposure.
Heating helps keep critical sensor surfaces clear, but the heater must supply enough energy to counter heat loss to the surrounding environment. An exposed site can place greater demands on the heating system than a sheltered installation.
The practical approach is to assess the worst expected combination of temperature, wind and icing, then select a sensor and power supply that meet the requirements. The heater’s current demand should be checked against the available supply, especially for remote sites using batteries or solar power.
Heating reduces the risk of ice disrupting measurement; it does not guarantee that a sensor will remain ice-free in every condition.
The full explanation is in What is the best wind sensor for harsh environments?
Related applications and resources
ApplicationDe-icing and winter operations
Wind data for airport operations in cold and freezing conditions.
ApplicationWind turbine control
Wind measurement for turbines operating in cold and exposed locations.
NewsHeated WindObserver
Read about the heated two-axis WindObserver developed for extreme weather applications.
NewsHeated MaxiMet for low temperatures
Learn about the heated option available for MaxiMet compact weather stations.
Speak to our team
Tell us what you need to measure, where and under what conditions. We’ll help you work out the appropriate approach.
Frequently asked questions: wind measurement in icing conditions
Ultrasonic anemometers can operate in icing conditions when designed with suitable heating, but no anemometer is immune to ice. Ice can obstruct the acoustic path between transducers and interrupt measurement. Heated Gill models help reduce this risk, with suitability depending on icing severity, exposure and the sensor specification.
Gill’s heated wind sensor options include WindObserver 65, 70, 75, 90 and II, WindSonic M and WindUltra. MaxiMet is available with transducer-only heating for less severe conditions. Check the individual model datasheet to confirm the heating arrangement and suitability for the intended site.
Power demand depends on the sensor model and heating configuration. WindObserver 65 heating is specified at 3 A at 24 V and WindObserver 70 at up to 7 A at 24 V. MaxiMet transducer-only heating is approximately 7 W. Confirm the exact heater demand before sizing the supply, particularly for solar- or battery-powered installations.
MaxiMet’s transducer-only heating, at approximately 7 W, is suitable for mild frost rather than severe icing. Where freezing rain, rime or sustained severe icing is expected, assess a sensor with a heating arrangement appropriate to those conditions and check the model specifications.
Heated WindObserver models operate from −55 to +70°C with heating, while WindSonic M and WindUltra are specified from −40 to +70°C. These ranges are model-specific. Check the current datasheet for the exact configuration and any additional environmental requirements.
Potentially, but the system must be designed around the sensor’s heater demand as well as the power needed for normal measurement and associated equipment. Heating can draw substantially more power than the sensor itself. For a solar-powered site, calculate the demand under expected cold-weather conditions and check that the panel, battery and power management system can sustain it.
No. Heating reduces the risk of ice accumulating on critical sensor surfaces, but severe icing can still interrupt measurement. The outcome depends on the type and severity of icing, wind exposure, temperature, heating capability and available power. Sensor selection should be based on the expected site conditions rather than temperature rating alone.