Light intensity is measured by means of a light meter or illumination
meter. You might think that it’s easy to make this kind of meter by connecting a
milliammeter to a solar (photovoltaic) cell. And this is, in fact, a good way
to construct an inexpensive light meter (Fig.).
More sophisticated devices might
use dc amplifiers to enhance sensitivity and to allow for several different
ranges of readings. One problem with this design is that solar cells are not
sensitive to light at exactly the same wavelengths as human eyes. This can be
overcome by placing a colored filter in front of the solar cell, so that the
solar cell becomes sensitive to the same wavelengths, in the same proportions,
as human eyes. Another problem is calibrating the meter. This must usually be
done at the factory, in units such as lumens or candela. Its not
important that you know the precise definitions of these units in electricity
and electronics.
Light meters or illumination meter./Lux meter
Reviewed by Bibi Mohanan
on
June 19, 2016
Rating:
Reviewed by Bibi Mohanan
on
June 19, 2016
Rating:
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