University of Bern, Switzerland

Institute of Applied Physics
ExWi Weather Station

References ExWi Weather Station

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> Latest Data Zimmerwald
> Latest Data Ceilom. (Zimm)
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> References for ExWi
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The weather station is situated on the roof of the Gebäude für Exakte Wissenschaften (ExWi), Sidlerstrasse 5, 3012 Bern, Bern, Switzerland. The coordinates are 46° 57' N, 7° 26' E, 575 m asl, this corresponds to 600 017 / 200 035 in the National Coordinate System.


The IAP Weather Station is a MILOS 500 model manufactured by Vaisala. Besides sensors for temperature, humidity, pressure, wind speed, wind direction, rain and solar irradiance, the weather station is equipped with a FD12P sensor to monitor visibility and present weather. The station is maintained by the research group "Radiometric Methods for Environmental Monitoring" of the Microwave Department, Institute of Applied Physics, University of Bern, Switzerland.


All sensors have an operating temperature range of at least -40...+60 °C.

Humidity and Temperature Probe: Vaisala HMP 45D

Consists of a HUMICAP® H-Sensor for relative humidity and a Pt 100 IEC 751 1/3 Class B sensor for temperature measurements.
Measuring range: -40...+60°C
Accuracy: ±0.8°C
Relative Humidity:
Measurement Range: 0.2...100%RH
Accuracy @ +20°C: ±2% (0...90%RH)
Accuracy @ +20°C: ±3% (90...100%RH)
Temperature dependence: ±0.05%RH/°C

Barometer: Vaisala PTB100

Consists of a BAROCAP® sensor.
Pressure range: 800...1060hPa
Total accuracy: ±1.5hPa

Anemometer: Vaisala WAA15A

Measuring range: 0.4...75m/s
Accuracy: ±0.17m/s

Wind Vane: Vaisala WAV15A

Measuring range: 0...360°
Resolution: 5.6°
Accuracy: ±3°

Rain Gauge: Vaisala RG 13H

Tipping-bucket type.
Area of aperture: 400cm²
Resolution: 0.2°

Pyranometer: Kipp & Zonen CM3

ISO 9060 second class pyranometer.
Spectral sensitivity: 0.3...2.8microns
Field of view: 180°
Non-linearity: ±2.5%
Temperature dependence: 0.12%/°C

Combined visibility and present weather sensor: Vaisala FD12P

The optical arm measures optical visibility with the forward scatter measurement principle. Additional sensors are used to determine precipitation and temperature. This allows for the calculation of the weather type according to the WMO code table 4680.

Martin Lainer, Institute of Applied Physics, University of Bern
Last update: 2009-04-22 15:36 CEST