Glow Products Charged under Sunlight
Sunlight contains a certain amount of UV Rays in them. Glow in the dark products react or get charged faster when exposed to UV Rays. With the latest range of Glow in the Dark Products which can glow for 15 hours or more, many have the thinking that they can leave glow products outdoors throughout the day and it should glow brightly throughout the night.
It does not work that way. To understand why, we have to look at the way glow products absorb and give out light energy.
When glow products are exposed to light (preferably those with UV rays as these charge faster), they absorb these light rays. But at the same time, they are also releasing this light energy in the form of a glow which can only be visible in the dark. Since it is under bright light, this release of light cannot be seen. The process of absorbing light when under a light source, is much faster than the release; a characteristic which enables glow products to reach its maximum charge when exposed to light for some time.
So now when we have a glow product left out in the sunlight throughout the day, it can reach its full charge in a matter of minutes and retain its full charge as long as the sun is bright. If you were to bring the glow products in a dark place, you can immediately see the brightness.
The problem with sunlight is that it does not set immediately but takes its time to become dark during the process called sunset. During this time, which can take about 2 hours until it finally becomes dark, the glow product has already started to release its light energy, so by the time the sun has set, the glow product has already given out more than 50% of its light energy. In theory, this meant that a product with a stated glowing time of 15 hours can only glow for about 5 hours if used in this manner. Also remember that glow in the dark products work best when the environment it totally dark.
To better understand the release process, take a look at the graph below:
Glow in the dark products are best suited in areas where there is a sudden loss of light. Instances of this could be like in a blackout or in a park or public area where the lights are switched off after a certain time.