The SunMate alerts the user a possible over-exposure to ultraviolet rays from sunlight. This handy device is easy to understand and you do not need a technical background. The LEDs indicate the UVI levels according to the chart below. As you may notice, the gaps between the ranges in the table above overlap to make the detection continuous.

1 LED (the Ultraviolet is minimal)

2 LED ((the Ultraviolet is low)

3 LED ((the Ultraviolet is moderate)

4 LED ((the Ultraviolet is high)