A rugged data-logging meter that reads electrical conductivity, total dissolved solids, and salinity in water, storing results on an onboard-expandable SD card at sampling intervals from one second up to several hours. It covers conductivity from 200 uS/cm to 200 mS/cm and TDS from 200 to 200,000 ppm, with automatic temperature compensation and a backlit dual LCD showing hold and min/max readings. Supplied as the meter with its conductivity/TDS/salt probe in a hard carrying case, running on 6 AA batteries or an optional AC adapter.