Most standard lab spectrophotometers require one light source, most commonly a tungsten halogen bulb, which produces one beam for operation. A UV spectrophotometer has two separate bulbs, one that is the same as the light source found in a lab spectrophotometer and one that is unique, a deuterium lamp. Although the UV spectrophotometer only uses one light source to create the information, both bulbs are used to create the range of light needed. Models of UV spectrophotometers will also have several different scanning speeds to allow testing of different types of materials in the samples. These speeds range from low to medium to high with a maximum speed of 1000nm per minute. The machines do use a similar found position cell holder as a standard cell holder but typically much smaller samples can be used in a UV spectrophotometer than in a standard lab spectrophotometer.