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Lichtenheldt Produkte


Radiometer „Lightmill“

The Radiometer is an invention of the English physicist Crooks and show vividly the conversion of light into kinetic energy. The black surface of the solar wing – wheel (a circle of elements which are sensitive to light) absorbs much more light energy than the bright one. Because of the stronger heating of the air molecules on the black surfase a higher pressure arises there that leads to a rotary motion of the solar wings. This rotary motion is the result of the light incidence (radiometer is standing or hanging by the window) and as well as possible in the gleam of light-bulb inside a room (no cold neon light). The more intensive the light is the faster the solar wheel moves. As the rotary force on the solar wing-wheel must be higher than the resistance of the air molecules a partial vacuum is generated in the ball. This demonstration model of a physical process show how light is transformed into kinetic energy. Therefore the radiometer may be called a small solar power station.

The Goethe Barometer

The „Goethe Barometer“ is aclosed, bulbous glass jar with a long spunt, called a “break“. A functional wall decoration, it clearly shows how the weather will be during the few days. Setting up your „Goethe Barometer“ is easy! Just fill the jar about half-way with boiled or distilled water. This will prevent unnecessary calcification inside the barometer. The water in the jar and beak should be the same height. Optionally, you may dye the water with the accompanying color tablets to achieve additional decorative effects. Finally, keep in mind that it is important for the accuracy of your barometer to have a elativety constant temperature. It is not optimal to hang your barometer near or in direct sunlight. Once you´ve set up your barometer you will be able toread it and predict upcoming change in the weather. The varying weather conditions and resulting changes in air pressure will cleary show on the Goethe Barometer. For example, the high air pressure that accompanies pleasant weather results in the liquid level in the beak dropping. The barometer is a beautiful and effective tool.

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