Digital Conductivity meter is precise and rugged instrument designed for most accurate measurement of conductance. Generally the measurement of conductance is not any harder than measuring resistance in fact conductance is the inverse of the resistance. However, most ohm meters operate from direct voltage and current if were used in a liquid it would invariably give raise some sort of electrolysis that would distort the measurement. To counter the electrolysis the meter must operate with on AC voltage or current of sufficient high frequency.