21-3428 Serial number SBE 21 Baseline **From SBE 21 Manual:** The SBE 21 SeaCAT Thermosalinograph is an externally powered, high-accuracy, conductivity and temperature recorder, designed for shipboard determination of sea surface (pumped-water) conductivity and temperature. Seabird Electronics Organizational Temperature 3428 -5 to +35 0.001 (°C) Conductivity 3428 0 to 7 0.0001 (S/m)