The HI5521 is an advanced research grade benchtop pH/mV/EC/TDS/Salinity/Resistivity meter that is completely customizable with a large color LCD, capacitive touch keys, and USB port for computer connectivity. The HI5521 is rich in features including data logging, alarm limits, comprehensive GLP, and many more while retaining simplicity in use with both dedicated key for routine operation and virtual keys that guide the user through setup options. The HI5521 ensures confidence in pH measurements with the exclusive Hanna Instruments CAL Check™ feature that alerts the user to potential problems during calibration including if the buffer is contaminated or the probe needs to be cleaned.