... the functions of integral holding, peak height and area, auto zero adjusting, deuterium lamp and background, multi-linear and nonlinear curves ... As, Se, Sb, Bi, Pb, Sn, Te, Ge, In, Tl, Cd and Zn lower than ppb level with cold atomic mercury ... I/O port AAS Highly Integrated Micro Digital Circuit Auto Zero Adjusting Spectrophotometer For Elementary Analysis Analyzer