The Extech DO700 is a 9-in-1 portable dissolved oxygen meter that measures DO concentration/saturation, pH, mV, temperature, conductivity, TDS, salinity and resistivity. This has automatic salinity compensation and manual barometric pressure compensation for DO measurements. It also features automatic one-button calibration for 4, 7 and 10 pH with a choice for three-point calibration for better accuracy and automatic temperature compensation. The scope of delivery includes a DO probe, pH/mV/temperature electrode, polymer conductivity cell, pH and conductivity calibration solutions, batteries and hard case.