Libra S21/22 are simple-to-use instruments with advanced performance, incorporating Xenon lamp technology for longer source lifetime and lower maintenance costs. A further benefit of this design is optical noise compensation to improve signal to background measurements. Instrument Performance Validation (IPV) is included as standard, and will benefit any laboratory that needs to prove the quality of their results; the GLP results can be viewed on the display or printed out. In addition to measuring absorbance, transmittance and concentration, they provide a standard curve routine for analyte determination. Wavelength scan (with zoom), absorbance changes with time, reaction rate determinations and standard curves can be displayed as graphics and printed out. User defined equations can be entered using multi-wavelength mode and up to 18 methods can be saved in separate operator folders. The instrument can be upgraded for more sophisticated applications, as well as data manipulation, with Acquire Software and a PC. With its large sample compartment and wide range of accessories, Libra S22 is a versatile and reliable instrument for use in any laboratory performing general-purpose measurements. The S21 covers the visible wavelngth range whilst the S22 covers the UV/Visible range.