Different applications require different levels of water purity. As an example, the electrical conductivity of drinking water will usually be less than 1 mS/cm, while a semiconductor plant or pharmaceutical plant requiring very pure water would aim for the electrical conductivity of water to be less than 1 µS/cm.
This 15 minute webinar recording explains how produce wash water is monitored to ensure that fruits and vegetables are kept safe and clean.
Any style of electrochemical sensor requires calibration in order to provide accurate measurements. The process of pH sensor calibration is very straightforward, but many users are not aware of the considerations and reasoning behind this requirement.