Extech PH90 Waterproof PH Meter, Green

Rugged replaceable flat surface PH electrode for quick on-the-spot PH measurements Simultaneous display of PH and temperature 2 or 3 point calibration automatically recognizes buffer solutions (order PH buffers separately) Pts (percent of slope) tells you when it's time to replace your electrode (below 70% or above 130%) Automatic temperature compensation