Aiming at improving the measurement accuracy and reliability of the trace ion concentration in power plant steam water system

the main source of uncertainty for detection of trace chlorides in the steam water systems by ion chromatography was analyzed and each uncertainty component was quantified on the basis of the uncertainty evaluation mathematic model.The analysis shows the uncertainty component caused by repeatability was the smallest while that by the recovery rate correction factor was the largest.Moreover

this model was applied in chloride ion detection in feedwater system of a power plant.The results show that

with confidence of 95%and coverage factor of 2

the expanded uncertainty of the measurement was 1.28 μg/L.So the chloride ion concentration in feedwater system of the power plant was(10.92±1.28)μg/L.