Abstract：Objective To introduce the calibration processes of XT-1800i automated hematology analyzer and analyze the variation of calibration coefficients retrospectively to master the instrument state. Methods According to Calibration Guide for Blood Cell Analysis, the variation of calibration coefficients of various parameters of XT-1800i automated hematology analyzer which were calibrated ten times from 2008 to 2013 was analyzed. Results During the first calibration process in 2013, platelets (Plt) deviation of the instrument was greater than 3.0%, which indicated that the calibration coefficient of platelets (Plt) need to be adjusted while the calibration coefficients of other items need not to be adjusted. Except for red blood cell (RBC), the calibration coefficients of other items had changed in five years. The biggest change was occurred in mean corpuscular volume (MCV). Conclusion The parameters of hematology analyzer which was used for a period of time would be drifted and need to be calibrated at regular intervals.
