Weather Measurers By Benjamin Holmes

Rain Gauge One way of measuring rain is with a rain gauge. Rain gauges are a tin with a funnel running into a measuring cylinder. They are positioned off the ground, so rain does not bounce back in. They measure the depth of rain over a given area.

Max and Min Thermometer Max and min thermometers measure the maximum temperature and the minimum temperature. They work because they push two markers. One is maximum and one is minimum. One side goes up as the other goes down. You tap them to reset and the marker falls back to the mercuary.

Anemometer An anemometer is used for measuring wind speed. It does this by spinning when blown. It has a number of cups which capture the wind. The rate of spinning is used to calculate the wind speed.

Wind Vane Wind vanes tell you the direction of the wind. They do this by being a shape that gets blown by the wind until it is pointing in the direction the wind is coming from.

Cloud coverage Clouds coverage is measured in oktas. This is done by getting a piece of something and cutting 8 squares in it and checking how many are covered in cloud.

Sunshine Hours of sun are measured by putting a piece of paper under a glass ball, then as the light is focussed through it burns the paper. The burnt parts are then measured.

Thermometers Thermometers measure temperature. There are two major types of thermometer wet and dry. Dry measures air temperature and wet measures the temperature of liquids. The liquid is usually mercury or alcohol.

BAROMETER Air Pressure is measured using a barometer. Pressure is measured in millibars. When this happens a coiled chamber inside the device expands or contracts. This moves a needle showing the pressure.

HYGROMETER Hygrometers measure humidity in the air. They do this by having a hair that expands and contracts changing where the needle is pointing.

Weather Station Weather stations are where all the measuring equipment is held. Some of them are on the out side, e.g. the rain gauge some on the inside e.g. the thermometer.

Stevenson Screen Stevenson screens are used to keep the sun off the thermometers in a weather station because it would give an inaccurate temperature reading.