Carsten Thirstrup, Alan Snedden, and Hans D. Jensen. AbstractâThis paper reports a closed-flow-loop electrolytic conductivity measurement system enabling ...
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL. 66, NO. 10, OCTOBER 2017
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Bridging the Gap Between Ultrapure Water and Reference Materials in Electrolytic Conductivity Measurements Carsten Thirstrup, Alan Snedden, and Hans D. Jensen
Abstract— This paper reports a closed-flow-loop electrolytic conductivity measurement system enabling calibration of conductivity sensors from the conductivity level of ultrapure water (UPW) at 5.5 µS/m up till the range of 10 to 140 mS/m, where stable certified reference materials (CRMs) for conductivity are available. The system is traceable to the SI unit system. A comparison made with another electrolytic conductivity measurement system, which is based on Jones-type conductivity cells designed to be used primarily for conductivities larger than ∼10 mS/m, shows an agreement better than 0.1%. The most commonly used calibration method of conductivity sensors is based on CRMs and the extrapolation of the data to low conductivity values ( 10 000 μS/m, deviation is larger [see Fig. 4(a)] because the measured resistance is low (
