Ion 700 meter measures pH, mV, relative mV, ion concentration and temperature. Automatic temperature compensation (ATC) maintains reading accuracy even with fluctuating temperatures. Models feature five-point pH calibration with automatic buffer recognition for both USA (pH 1.68, 4.01, 7.00, 10.01, 12.45) and NIST (pH 1.68, 4.01, 6.86, 9.18, 12.45) pH buffers. Meters additionally feature ion concentration calibration of up to 5 points.