Personal UV monitor

17 Jun 2002

A solar sensor wristwatch based on a gallium nitride (GaN) detector could help fight the rising tide of skin cancer - one of the most virulent forms of the disease.

GaN is particularly sensitive to ultraviolet radiation, and the sensor in the watch monitors the sun's UV intensity throughout the day, telling the wearer when he or she has spent long enough in the sun.

Wearers enter their particular skin type and the protection factor of the sunscreen they are using. The UV sensor then tracks the accumulative sun exposure and beeps when the "safe" period has expired.

Because of GaN's sensitivity to UV radiation, the sensor continuously recalculates the safe exposure time as the sun's intensity rises and falls through the day, or if it is hidden by clouds at any point in time.

Suppliers sp3 plus warn, however, that the watch only provides a guide for customers, and does not offer any protection from UV radiation in itself.

The water- and shock-resistant personal UV meters are made by APA Optics of the US, and are available through supplier sp3 plus. MH

Story courtesy of Opto and Laser Europe magazine