Patent ID: 9488611
Filing Date: 2016-11-08
CPC Classification: G01N

Claim Text:
1. A method of measuring conductivity at or below 100 μS/cm of a liquid sample using a contacting-type conductivity sensor, the method comprising: applying a first excitation current using an analyzer, through a first pair of leads, to the contacting-type conductivity sensor at a first drive frequency, wherein the first pair of leads are placed in contact with the liquid sample having a source impedance that generates an error in conductivity measurement and wherein the excitation current at least partially extends through the liquid sample; determining a first voltage response through a second pair of leads of the contacting-type conductivity sensor to the first excitation current using the analyzer; applying a second excitation current using the analyzer, through the first pair of leads, to the contacting-type conductivity sensor at a second drive frequency different than the first drive frequency; determining a second voltage response through the second pair of leads of the contacting-type conductivity sensor to the second excitation current using the analyzer; providing a corrected conductivity output based, at least in part, on the first and second voltage responses wherein the corrected conductivity output is a function of the first and second voltage responses, and comprises a reduced error with respect to the source impedance; and wherein the second drive frequency is higher than the first drive frequency.