UVI lamps (doped, straight, low pressure lamps)
UVC lamps designated UVI emit light mainly of the wavelength 253.7 nm. They are doped with a special amalgam which reduces the pressure of the mercury vapour. The amalgam means the lamp will give twice the power per unit of length produced by a normal low pressure light. Three different types of quartz are used in these lamps according to the intended application. Very compact, high-performance equipment can be construct- ed with this type of lamp. The fact that they can be used in water at quite high temperatures makes them very popular.