The Pharmacia LKB Optical Unit UV-1 is a fixed wavelength UV monitor with a control unit and an optical unit. A mercury lamp is the stable light source, a reference cell eliminates baseline drift. The output signal can be recorded in either AU or %T. Sensitivity range between 0.01 and 2 AUFS. The UV-1 offers a range of three detection wavelengths: 254, 280 and 405 nm.