Evaluation of Uncertainty for Determination of Nickel Content in Low Alloy Steel by FAAS

The nickel content in low alloy steel was determined by FAAS according to GB/T 223. 54-1987, the cause of uncertainty in measurement process is analyzed and the uncertainty of measurement results is evaluated. It is found that the measurement uncertainty is mainly derived from sample weighing, determination of volume and concentration of the sample solutions. The uncertainty for the determination of the concentration of the sample solutions in instruments is from the preparation of standard solution, fitting of calibration curve and the repeatability of measurement. Then the method to improve the measurement accuracy is proposed.