PURPOSE OF STEVENSON SCREEN

• Stevenson screen is a wooden box specifically designed for housing four thermometers which record the surface air temperature in degree C.

• These four thermometers are maximum, minimum, dry and wet bulb thermometers

STEVENSON SCREEN OF EQUIPMENT

• A Stevenson screen is a rectangular wooden box of dimension length 56 cm, width 30 cm and height 40 cm.

• Double roof-side walls are louvered providing free movement of air to the thermometers bulb.

• The air space between the double roof and white painting prevent direct heating from the intensity of sunlight.

• Stevenson screen is painted white and is mounted on four wooden supports, the bottom of the screen being at 1.22 m (4 ft) above the ground.

• The screen is set up with its door facing north side (opening downward) so that minimum sunlight would enter while the observer is reading the instruments.

• The use of the screen is to protect the thermometers from direct heating from ground and neighbouring objects and from losing heat by radiation at night.

• Stevenson screen also protect instruments from rain and snow and allows free air circulation

FRANCHISEE REQUIRED PLACES