Arctic Climate Measurement SolutionsIce resistant meteorological sensors

Thies CLIMA: Arctic Climate Models

Ultraschall Anemometer, Ultrasonic 2D Compact

Laser Precipitation Monitor (LNM)

Ultraschall Anemometer, Ultrasonic 2D

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Ice-Free. Ready to Perform. Extremely Robust

Meteorological measurement technology for Arctic and high alpine locations must do more than just with stand low temperatures. In practice, the greatest challenges arise not only from the cold. but from the interaction of temperature, wind, humidity, and precipitation. It is this combination that leads to icing-and thus to measurement errors or functional failures.

Thies CLIMA there fore does not consider Arctic and cold climate applications in isolation based on temperature limits, but rather on real meteorological stress scenarios. On this basis, Thies has developed its own icing standard. which describes the conditions under which measuring dewces can be operated continuously and ice free. We carry out tests on selected devices to ensure they meet the icing standard, while the philosophy of ro bust construction and system consideration applies to all models.‎‎‎‎

Probability oficing situations occurring depending on wind speed and air temperature.

Arctic climate means more than just "low temperatures"

Many specifications for extreme climatic conditions refer exclusively tothe permissible operating temperature range ofa device. This view is too narrow. In real operating environments, the following factors all have an effect at the same time:

Very low air temperatures
High wind speeds [wind chill effect)
humidity, snow, freezing rain, or freezing precipitation

Under these conditions, itis notthe minimum operating temperature that determines whether a device remains ice free and delivers valid measurements, but ratherthe energy balance oft he overall system. The Thies CLIMA icing factory standard precisely reflects these relationships.

Thies CLIMA Factory Standard ICING

The Thies icing factory standard

The Thies icing factory standard describes the ic ing resistance of meteorological measuring in struments under realistic environmental conditions. lt takes into account not only temperature, but also:

‎Wind speed and convective heat loss
Available heating power
System influences such as powersupplv and line losses
Note: Humidity or precipitation types are not considered separately in the test, as the critical condition for icing is primarily determined by the temperature and heat balance of the sensor. At temperatures above freezing, no relevant ice formation occurs, while atvery low.

The aim is not to achieve a blanket "free of icing under all circumstances" guarantee, but rather to provide a physically reliable statement as to the combinations of temperature and wind at which reliable operation can be ensured. Typical limits are clearly stated. If these are exceeded, icing can no longer be guaranteed to be excluded.

‎Permissible comparisons &standard classification. What is comparable. MILSTD, IEC, ISO?

‎‎

Environmental and military standards such as MILSTD810 or IEC climate tests make valuable contributions to the evaluation of robustness, transportability, and material resistance.
However, they differ fundamentally from the Thies icing factory standard:

Focus on individual tests instead of combined weather effects
Evaluation of survivability, not measurement quality
Icing usually as an isolated test case

The Thies icing standard complements these as preaches by focusing on the realworld operation of meteorological measurement technology under icing conditions.
‎‎‎‎

Factory Standard Icing - Example Thies CLIMA Wind Transmitter

Technical design criteria relevant to the Arctic climate

Technical aspect	Implementation at Thies CLIMA	Advantage in Arctic climate applications
Measuring method	Ultrasound-based wind measurement without moving parts	No mechanical interference from ice or snow.
Basic function at low temperatures	Can also be measured unheated to below −40 °C	Heating serves as protection against icing, not just to ensure measurement capability.
Heating concept	Sensor arms, ultrasonic transducers, housing surfaces (depending on model)	Protection of all surfaces relevant to measurement.
Heating power (typical)	Heating power (device-dependent) Up to approx. 90 W / 250 W depending on device type	Heating power optimized for device type and area of application.
Supply voltage	24 V / optional 48 V, special connection cables	Best possible supply to the heating system close to rated power.
Energy balance	Consideration of wind speed, humidity, precipitation	Prevention of negative heat balance (wind chill effect), surface temperature >0°C in the specified range.
Construction design measures	Minimized ice accumulation surfaces, robust geometries	KoDesign measures to prevent ice formation.
Proof of icing resistance	Testing according to Thies icing standard (STD 012001 / 012002)	Possibility of precise specification of icing resilience, depending on wind/temperature.

Table: The evaluation is based on the model and configuration in accordance with the Thies CLIMA icing standard (STD 012001 /012002).

Suitable devices & applications for Arctic climate applications

Selected measuring devices are designed for use in Arctic and cold climate conditions. Their suitability is based not only on temperature limits. but also on a balanced energy balance between heating power and heat loss. Depending on the sensor type, heating concept, and system design, different icing scenarios can be reliably covered.

Meteorologische Messtechnik von Thies CLIMA für Arctic-Climate-Bedingungen

Ultrasonic anemometer, Ultrasonic 3D with heating elements on the shaft, arm, and sensor head.

PRODUCTS: Arctic climate wind measurement technology places particularly high demands on equipment:

In addition to low temperatures, high wind speeds also play a role here, significantly increasing heat loss (wind chill effect). The following ultrasonic anemometers are designed so that all external
surfaces relevant to icing are heated as required. The heating output is only activated when itis necessary to prevent ice buildup. Only special models from the ultrasonic anemometer series are specifically tested according to the Thies icing standard. The decisive factor is not the highest possible heating power, but a stable energy balance that prevents surface temperatures from falling below
freezing.

We recommend the following models (according to THIES icing standard 012002)
Ultraschall-Anemometer (2D / 3D)
US 2D, 4.382x.4x.xxx
US 2D, 4.3820.34.398
US 2D, 4.3875.6x.xxx
US 2D Compact, 4.3877.xx.xxx
US 2D Compact, 4.3875.8x.xxx
US 3D, 4.383x.4x.xxx

Heated mechanical wind sensor
Wind direction sensor with heating, 24 VAC/DC, max. 60W
4.3129.80.xxx
4.3129.80.000
Compact wind sensor with heating, za VAC/DC, max. 60 W
4.3519.40.xxx
4.3519.40.000
4.3619.40.000
4.3619.40.xxx

Precipitation measurement technology from Thies CLIMA: 3D disdrometer

PRODUCTS: Precipitation measurement & sensor combinations under Arctic Climate

When measuring precipitation. icing problems arise primarily due to moisture, snow, and freezing rain. This requires multi stage heating concepts that take into account not only individual sensor areas, but the entire measurement system. Thies precipitation measuring devices have separately controlled heating circuits that are activated depending on the ambient temperature. The heating functions can be monitored diagnostically and integrated in to the system.

Example devices for ice resistant precipitation measurement:
Laser-Precipitation-Monitor (5.4110.00.xxx, option with bracket heating)
Laser-Precipitation-Monitor (5.4110.10.xxx option with bracket heating)
3D Stereo Disdrometer (5.4120.xx.xxx)
Precipitation Analyzer (5.4107.xx.xxx)
CLIMA Sensor US (with heating, Option)
Rain Gauge (5.4032.45.008)

FAO Frequently asked questions

Why is a specification such as "-50 °C operating temperature" not suffident? Because icing is not caused by temperature alone. Wind, humidity,and precipitation have a significant impact on heat loss. The decisive factoris whether the heating capacity can compensate forthese losses.

What exactly does the Thies icing standarddescribe? It describes the combinations oftemperature and wind speed under which a device can be operated reliably without icing - based on real measurements and operating expedence.

Does a limit value mean that operation is not possible above it? No. It means that under these conditions, freedom from icing can no longer be guaranteed. This is a deliberate and technically correct distinction.

What role does the power supply play? A significant one. Line losses and available heating power directly influence icing resistance. That is why as 48V systems are recommended for extreme locations.

Are MIL-STD tested devices automatically suitable for Arctic conditions?‎ Not necessarily. MlLSTD tests evaluate robustness, not longterm measurement quality under icing conditions.‎

GLOSSARY Arctic Measurement

Icing: Formation of ice due to freezing moisture or precipitation on device surfaces.

Windchill effect: Increased heat loss due to wind, which intensifies the effective cooling ofa body.

Energy balance: Comparison ofheating output and heat loss due to environmental conditions.

Thies icing factory standard: Internal standard forevaluating the icing resistance ofmeteorological measurement technology under realistic climatic conditions.

Arctic/cold climate: Operating environments with extreme meteorological conditions, not defined exclusively by air temperature.‎

CONTACT - best in person.

Learn more about our Artcic Climate measurement technology and find the right devices for your projects.
Advice session "ARCTIC CLIMATE"