Anemometer Thies First Class Advanced II

Classification acc. to IEC 61400-12-1 Edition 2.0 (2017-03)

Class A and B

  Class A* Class B**
Heating ON
or temperature range: 15 ... 40° C
1.8 2.0
Heating OFF 2.3 2.7

*Class A: simple terrain (-3 ... 3° tilt) (low turbulences) (0° ... 40°C)
**Class B: complex terrain (-15 ... +15° tilt) (high turbulences)  (-10° ... 40°C)
Source: Classification report Class A and B

Class S for different air temperatures

  -10°C -5°C 0°C 5°C 10°C 15°C 20°C 25°C 30°C
Class 'S' 2.8 2.6 2.3 2.1 1.9 1.8 1.8 1.8 1.8

The Class S is obtained using the same classification parameters as for Class A with the exception of the temperature.
Source: Classification report Class S temperature

Operational standard uncertainty acc. to IEC 1400-12-1

The operational standard uncertainty describes the maximum deviation of the wind speed measured by the anemometer compared with the real wind speed. The table indicates the operational standard uncertainty at 10 m/s:

  Class A* Class B**
Heating ON
or temperature range: 15 ... 40° C
0.10 m/s 0.12 m/s
Heating OFF 0.13 m/s 0.16 m/s


Optically-scanned cup anemometer

Thies First Class Advanced gives outstanding performance. The sensor has been classified acc. to IEC 61400-12-1 Edition 2.0. It gives optimal dynamic performance with the following characteristics:

  • High accuracy
  • Minimal deviation from cosine line
  • Excellent behaviour to turbulences
  • Minimum overspeeding    Small distance constant
  • Low start up value
  • Low power consumption
  • Digital output

The sensor is designed for measuring the horizontal wind velocity in the field of meteorology, climate research, site assessment, and the measurement of capacity characteristics of wind power systems (power curves). The patented design is the result of long testing in the wind tunnel. The sensor features dynamic behaviour also at high turbulence intensity, minimal overspeeding, and a low starting values. It requires only low maintenance thanks to its low-inertia and ball-bearing cup star. The anemometer is equipped with electronically regulated heating to guarantee smooth running of the ball bearings and prevent icing of shaft and slot during winter operation.


Physical functionality

Optically-scanned cup anemometer

Delivered signal

Frequency output (pulse)


0.3 ... 50 m/s      1% of meas. value or < 0.2 m/s


Correlation factor r between frequency f and wind speed y
y = 0.0462 × f + 0.21 typical
r > 0.999 99      (4 ... 20 m/s)

Starting velocity

< 0.3 m/s


0.05 m wind run

Distance constant

< 3 m (acc. to ASTM D 5096 - 96)     3 m acc. to ISO 17713-1
Turbulent flow Deviation Δv  turbulent compared with stationary horizontal flow
-0.5 % < Δv < +2 %
Frequency < 2 Hz
Inclined flow
- mean deviation from cosinus line
- Turbulence effect

< 0.1 % (in range of ±20°)
< 1 % (in the range up to 30% turbulence intensity)

Wind load

Approx. 100 N @ 75 m/s

Operating range

Measuring range

0.3 ... 75 m/s

Survival speed

80 m/s (mind. 30 min)

Permissible ambient conditions

-50 ... +80 °C, all occuring situations of relative humidity

Electrical data

Output signal

Form rectangle, 1082 Hz @ 50 m/s, supply voltage max. 15 V

Electrical supply for optoelec. scanning

Voltage: 3.3 ... 48 VDC (galvanic isolation from housing)
Current: 0.3 mA @ 3.3 V (w/o external load)
              < 0.5 mA @ 5 V (w/o external load)

Electrical supply for heating

Voltage:  24 V AC/DC (galvanic isolation from housing)
Idling voltage: max. 30 V AC, max. 48 VDC
Power consumption:   25 W



8-pole plug-connection for shielded cable in the shaft


on mast tube R1”


290 x 240 mm

Fixing boring

35 x 25 mm


approx. 0.5 kg

Material Housing

Cup star

Anodised aluminiun

Carbon-fibre-reinforced plastic

Type of bearings

Metallic ball bearings


IP 55 (DIN 40050)


EP 1 398 637
DE 103 27 632
EP 1 489 427


EN 61000-6-2:2001 (immunity)
EN 55022:2001, Class B (interfering transmission)





Plug Pin No.    


Ammonit Cable Wire Colour     Meteo-40     Supply Sensor
Wind speed Pulse output


white CNT  
Supply 3 red   9 ... 36 V*
Ground 2 black   Main Ground
Heating 7
orange, orange   24 V AC/DC
8 violet, violet  

* Supply voltage for usage with Meteo-40 data loggers.
Cable type without heating:      LiYCY 3 x 0.25 mm²
Cable type with heating wires: LiYCY 7 x 0.25 mm²

Connection recommendations for the cable shield

Sensor carrier Sensor Shielding / Ground
Metallic met mast, grounded Non-isolated mounting on the met mast (e.g. by using metallic brackets, holders, etc.) Connect cable shield only at the side of the data logger to ground.
Metallic met mast, grounded Isolated mounting at the met mast (e.g. by using non-metallic brackets, holder etc. or  metallic brackets, holders etc. with isolated plastic adapters) Connect cable shield at sensor plug and at the side of the data logger to ground.
Metallic met mast, non-grounded Non-isolated mounting on the met mast (e.g. by using metallic brackets, holders etc.)