With liquid crystal thermal sensors, these cards are unique, simple, inexpensive tools for advertisement.
A simple, reusable device that indicates the ultraviolet light intensity. Excessive levels of UV light can cause sunburn, premature aging of the skin, and skin cancer. The UV Card measures the strength of UV light (in about 20 seconds), to help you determine the optimum level of sunscreen SPF to use.
Hold the card so that its face is exposed to the light. Count to twenty. Look at the Ultra Violet sensor strip on the side of the card and compare it to the color chart. You'll be surprised at how much UV light exposure you receive even on cloudy days, or through windows. Enjoy the sun with our UV indicator testing cards.