Wind Sensoren: Anemometer

风速计

风速计测量水平方向的风速（速度）。这个参数对任何风点评估来说都是关键的。杯型风速计 是一种普通标准类型的风速计。它们结实而且能抵抗测风塔（杆）和横 木引起的湍流和斜风。根据国际标准（即MEASNET）每个风速计都应该经过单独校验并且备有通过验证的测量报告。一个测风塔上的风速计的数量从2个传感 器到6个不等。绝大多数风速计都可以装备电控加热装置。

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

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

Thies anemometer First Class Advanced

Vector anemometer L100 First Class

Thies anemometer Compact

Windsensor (RISØ) anemometer P2546A

Vaisala Anemometer WAA 252

Propeller Anemometer MODEL 27106T