... concentration of As, Se, Sb, Bi, Pb, Sn, Te, Ge, In, Model GD320N Atomic Absorption SpectrophotometerCharacteristics A Build-in computer ... 008mg/mlBackground calibration ability: Greater than 30 times.Standby Interface: RS 232 Instrument power supply: 220V, 3A, 50HzAccessoryMain accessories supplied with ... concentration of As, Se, Sb, Bi, Pb, Sn, Te, Ge, In, Tl, Cd and Zn lower than ppb level with ...