Wind sensors: Anemometer

Anemometers

Anemometers measure the horizontal wind speed (velocity). This parameter is crucial for any wind site assessment. Cup anemometers are the general standard type of anemometer. They are robust and resistant to turbulence and skew winds caused by masts and traverses. Each anemometer should be individually calibrated and equipped with a certified calibration report according to international standards (e.g. MEASNET). The number of anemometers applied at one mast can vary from a minimum of 2 up to 6 sensors (using Ammonit data logger Meteo-32X). Most anemometers can be equipped with electronically regulated heating.

Studies regarding anemometer behaviour

In order to analyse the accuracy of anemometer and define criterias for anemometer which are suitable for wind measurement the EU has financed three comprehensive studies in which well-known institutes like Risø and DEWI took part. The studies SITEPARIDEN, CLASSCUP and ACCUWIND indicate that the following criterias are crutial for anemometers used in wind measurement:

Angular response: anemometer behaviour according to variable flow angle
Turbulence behaviour: anemometer reaction on changing velocity
Bearing friction: influence of temperature on bearing friction

SITEPARIDEN (2001)

The SITEPARIDEN study describes that different cup anemometer types deliver measurement values that deviate up to 4%. Even calibrated anemometers had huge deviations.
Download SITEPARIDEN study

CLASSCUP (2003)

The CLASSCUP study analysed the reasons for the deviations in measurement values in the SITEPARIDEN study. The results are: Angular response, turbulence behaviour and bearing friction. The results of the study lead to a classification systeme which decribes the deviations of cup anemometers. Today the classification systeme is known as standard IEC 61400-12-1.
Download CLASSCUP study

ACCUWIND (2006)

The ACCUWIND study assessed the accuracy of anemometers on the market. The study indicates that cup anemometer Thies First Class Advance is the the best anemometer worldwide (see table 4-4).
Download ACCUWIND Study "Methods (1555)"
Download ACCUWIND Study "5 Anemometers (1556)"
Download ACCUWIND Study "Final Summary (1563)"
Siehe auch: Ammonit Presentation on ACCUWIND Thies First Class Advanced

Table 4-4 Classification of five cup anemometers according to IEC61400-12-1 using TRTC modem with DEWI tilt data and with influence of friction

Cup Anemometer	Class A*	Class B**
NRG max 40	2.4	7.7
Risø P2546	1.9	8.0
Thies First Class	1.5	2.9
Vaisala WAA151	1.7	11.1
Vector L100	1.8	4.5
Thies First Class Advanced	0.9	3.0

*Class A: reasonably flat sites
**Class B: complex terrain

Thies anemometer First Class Advanced

Thies First Class Advanced

Manufacturer: Thies

Order-No: S11100 / S11100H (P6101/P6101H)

Classified according to: IEC 61400-12-1 (2005-12),
MEASNET, CLASSCUP, ISO 17713-1

According to the ACCUWIND study (testreport1) it is the best sensor on the market!

Highly accurate anemometer, class: S 0.5 / A 0.9 / B 3.0
Outstanding performance
Optimum linearity: r > 0.999 99 (4 … 20 m/s)
High turbulence intensity
Excellent price-value ratio
Measuring range: 0.3 ... 75 m/s
Resolution: 0.05 m wind run
Temperature range: -50 ... 80°C
Low start up value
High survival speed
Minimum overspeeding
Very robust and weatherproof (seawater-proof)
Heatable

Downloads

Datasheet(M40)
Datasheet(M32)
ClassificationReport IEC61400-12-1

Thies anemometer Compact

Thies Compact

Manufacturer: Thies

Order-No: S12100H (P6140H)

Opto-electronic wind senor
with low power frequency output signal

Measuring range: 0.5 ... 50 m/s
Resolution: < 0.1 m/s
Temperature range: -30 ... 70 °C
Heatable
Not suitable for wind site assessment according to IEC 61400-12-1

Downloads

Datasheet(M40)
Datasheet(M32)

Thies anemometer Classic

Thies Classic

Manufacturer: Thies

Order-No: P6121H

Not accredited according to MEASNET and IEC
Often applied at offshore-projects

Class: 1 / A 1.9 / B 8.0
Measuring range: 0.5 ... 50 m/s
Resolution: < 0.05 m/s
Temperature range: -35 ... 80 °C
Heatable

Downloads

Datasheet(M32)

Vector L100 First Class

Manufacturer: Vector Instrucments UK

Order-No: S14100 / S14100H (P6171.03)

Classified according to IEC Standards
Optoelectronic wind speed sensor

Class: 1 / A 1.8 / B 4.5
Measuring range: 0.2 ... 75 m/s
Temperature range: -30 ... 70°C
Resolution: 0.05 m/s
Weight: approx. 0.5 kg
Low energy consumption
Robust and weatherproof (seawaterproof)
Non heatable

Downloads

Datasheet(M40)
Datasheet(M32)

WindSensor (RISØ) P2546

Anemometer RISO

Manufacturer: WindSensor (Risø)

Order-No: P6181

Classified according to CLASSCUP.
Very reliable anemometer

Class: 1 / A 1.9 / B 8.0
Measuring range: 0 ... 70 m/s
Negligible overspeeding
Temperature range: -35 ... 60°C
Starting speed: < 0.4 m/s
Non heatable

Downloads

Datasheet(M40)
Datasheet(M32)
Classification IEC61400-121CDV

Vaisala anemometer WAA 252

Vaisala WAA 252

Manufacturer: Vaisala

Order-No: S15100H (P6150H)

Non-freezing all weather sensor
Heatable cups!
Opto-electronic transducer

Class: 1 / A 1.7 / B 11.1
Measuring range: 0.4 ... 75 m/s
Temperature range: -55 ... 55 °C
Starting speed: < 0.5 m/s
Good effects in cold (arctic) climatic conditions
Heatable (cups included)

Downloads

Datasheet(M40)
Datasheet(M32)

Gill Propeller Anemometer MODEL 27106T

Young Propeller Anemometer MODEL 27106T

Manufacturer: Young

Order-No: S17100 (P6161)

Measuring of horizontal and vertical wind speed
Not classified according to MEASNET and IEC

Measuring range: axial flow 0 ... 40 m/s (90 mph)
Measuring range: all angles 0 ... 35 m/s (80 mph)
Temperature range: -50 ... 50°C
Distance constant: 2.1 m
Output signal: 1800 rpm (± 500 mV) = 9.0 m/s (20.1 mph)

Downloads

Datasheet(M40)
Datasheet(M32)

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