Sunburn is caused by UV radiation, either from the sun or from artificial sources, such as tanning lamps, welding arcs, or ultraviolet germicidal irradiation. It is a reaction of the body to direct DNA damage from UVB light. This damage is mainly the formation of a thymine dimer.xcessive UV radiation is the leading cause of primarily non-malignant skin tumors. Sunscreen is widely agreed to prevent sunburn and some types of skin cancer. Clothing, including hats, is considered the preferred skin protection method.
A protractor is used to measure angles. When surveying a theodolite is used. There are a number of tools on the market that perform angle measurement. A <b>protractor</b> is used to measure angles.<br />When surveying a <b>theodolite</b> is used.<br />There are a number of tools on the market that perform angle measurement. Minor edit?
The main surveying instruments in use around the world are the theodolite, measuring tape, total station, 3D scanners, GPS/GNSS, level and rod. Most instruments screw onto a tripod when in use. Tape measures are often used for measurement of smaller distances. 3D scanners and various forms of aerial imagery are also used.