BT520光密度计是意大利生产的自动化仪器，它能同时扫描16份标本，存储96个扫描图形．并具有删除、修改和校正功能。在这些功能中，白蛋白校正系数的选择最为重要，它关系到结果的准确性、重复性。由于仪器的F值可调范围很广（500～1500），如何正确选择F值，一直缺少可靠的指 The BT520 densitometer is an automated instrument produced in Italy. It can simultaneously scan 16 specimens and store 96 scan patterns. And has delete, modify and correct functions. Among these functions, the choice of albumin correction coefficient is the most important, which is related to the accuracy and repeatability of the results. Because the instrument’s F value can be adjusted to a wide range (500 to 1500), how to correctly select the F value has always been a lack of reliable fingers.