The Stevenson Screen

The Stevenson screen was invented by Thomas Stevenson (the father of the famous author of Kidnapped). Its main purpose is to allow the cold and warmth of the temperature to penetrate whilst preventing direct sunshine, wind or rain. This is done by having angled slats around the sides, and a double roof.

Security

It is better to compromise the quality of the weather data collected than risking the damage of equipment by unwelcome visitors. One of the best places in schools is in a courtyard within the school buildings. This affords some protection from outsiders.

Location

The ideal location is one where the distance from any object is 2.5 x the height of the nearest tree or building. This means that the trees or buildings will not act as a shield, making the measurements unrepresentative. This is applicable to the Stevenson screen and the rain gauge. Bearing in mind other factors (see above) some compromise may have to be achieved.

The Stevenson Screen

The door of the screen should face north so that when it is opened the sun does not shine on the instruments. (This relates to weather stations in the northern hemisphere.)

When weather monitors want to look at the instruments they should gently open and lower the door. Rough handling can cause the instruments to give false readings.

Maintenance

The water reservoir on the wet and dry thermometers needs to be kept topped up. The indicating liquid in the thermometers needs to be monitored, in case it becomes separated. The rain gauge needs to be kept clean. The Stevenson screen itself needs to be wiped occasionally to remove soot and pollution.

General Notes

A system needs to be set in place whereby only teachers and pupils under supervision are allowed access to the weather station. This is to prevent interference in the form of emptying or filling rain gauges, resetting maximum and minimum thermometers and general damage.
All health and safety concerns should be addressed.