A small gadget to measure exposure to ultraviolet radiation, called the UV Dosimeted, invented by Canterbury University computer engineer, Martin Allen could one day be made available to the public as a method to prevent skin cancer.

The sun-sensor device can be worn as a wristwatch or pinned to different parts of the body. The device which is battery-powered measures the wearer's true exposure to UV radiation as they move.

The meters are being worn in a joint study presently conducted in Niwa, Otago University and Auckland University.

Richard McKenzie, principal scientist of Niwa said that there could be enough UV to give a person about 30 separate sunburns on a summer's day.

On a summer's day, it takes about 10 to 15 minutes for skin damage to occur.

Mr Allen said, interests in the device have been coming in from Australia, Europe and the United States.

The scientists are working to develop a program using the device for schools to teach children about UV radiation - for instance, how it is blocked by clothing and clouds - and to reinforce the importance of sunscreen and protection from the sun.

Dr Allen said the device, however would not be sold to the public with an alarm to act as a cook-o-meter.

The danger is ... if someone wears it and they get burnt. That's completely the wrong message. The Cancer Society would disown us.

Extended exposure to solar UV radiation may trigger acute or chronic health effects on the skin, eyes and immune system.

A significant sign of UV overexposure is getting sunburns.

Skin cancer and cataracts can develop in the most severe cases.

However, small amounts of UV are beneficial for people and vital for the production of vitamin D. Under clinical supervision, UV radiation is used to treat rickets, psoriasis, eczema and jaundice.