In order to choose for an appropriate design of a radiation shield for the automatic measurements of air temperature and humidity, an intercomparison of seven different screens was organized from 1989 to 1995. At the instruments test site at KNMI in De Bilt, the Netherlands, the air temperature is measured every 15 seconds during a contiguous period of seven years. These temperatures are measured synchronously inside 7 screens of very different designs (different materials, shapes, sizes and type of ventilation)

http://www.dwd.de/EUMETNET/Berichte/TECO98temp.pdf

 

Temperature measurements: some considerations for the intercomparison of radiation screens By Jitze P. van der Meulen, Royal Netherlands Meteorological Institute

http://www.dwd.de/EUMETNET/Berichte/TECO00_temp.pdf

 

ON THE MEASUREMENT OF AIR TEMPERATURE IN THE PRESENCE OF STRONG SOLAR RADIATION

Abstract

The energy balance of small temperature sensors was modeled to illustrate the effects of sensor characteristics, particularly size, on the accuracy of readings in the presence of strong radiant loads, either of short or long wavelengths. For all but extremely small sensors, radiant exchange may lead to unacceptable errors. The common practice of using passively ventilated instrument screens was evaluated experimentally, indicating that differences resulting from the use of different models of shields may be an order of magnitude greater than the error resulting from sensor calibration. In the absence of technological innovation capable of reducing the error due to radiant exchange to negligible proportions, it is suggested that a standard methodology for calibrating and labeling the error resulting from the characteristics of the screens be adopted. Key words: temperature measurement, radiant exchange, Stevenson screen

http://www.geo.uni.lodz.pl/~icuc5/text/P_6_5.pdf 

Norwegian National Thermometer Screen Intercomparison

Merete H. Larre and Kjell Hegg

The Norwegian Meteorological Institute

Introduction

During the period January 2000 to May 2002 several temperature radiation screens were studied at a test field at the Norwegian Meteorological Institute in Oslo. As reference screen the standard screen at Norwegian weather stations was chosen, a construction of 1946, known as the MI-46 type. Three types of sensor screens were compared to the reference. These were the Vaisala and Young screens and the Norwegian Meteorological Institute’s own construction, the MI-74. The MI-74 type was represented in the test by four individual screens.

http://www.dwd.de/EUMETNET/Berichte/P1.1(01)Larre.pdf

 

Field comparison of artificial ventilated thermohygrometer and natural ventilated temperature and humidity measurements

Kjell Hegg

The Norwegian Meteorological Institute

N. H. Abelsvei 40, P. O. Box 43, Blindern, N-0313 Oslo

Norway

 

Introduction

The Norwegian Meteorological Institute started a National Thermometer Screen Intercomparison in January 2000. In September 2001 an artificial ventilated thermohygrometer was included in the intercomparison. The artificial ventilated temperature measurements are compared with temperature measurements obtained from a Pt100 sensor mounted in a wooden double-louvered screen type MI-46 which are the standard screen used at manned stations in Norway. Humidity measurements from the dew point type termohygrometer are compared with relatively low cost polymer type humidity sensors mounted in small size cylindrical temperature screens.

http://www.dwd.de/EUMETNET/Berichte/1.1(02)Hegg1.pdf.

 

Comparison of Meterological Screens for Temperature Measurment

http://www.wmo.ch/web/www/IMOP/publications/IOM-75-TECO2002/Posters/P1.1(14)Sima.pdf