YSI EcoSense EC30A

Accurate, economical pen-style measurement of conductivity, TDS and temperature. Features include an IP-67 waterproof housing; automatic temperature compensation; user-replaceable electrodes; 1- or 2-point calibration; clear, easy-to-read display; selectable units of measure for conductivity, TDS and temperature; selectable or auto-ranging for conductivity or TDS; HOLD feature locks readings on display; and >200 hour battery life with low battery indicator.