HBsAg] 311.0的计量单位？

http://www.rdbio.com/xueshuTips/309.html

https://www.hepb.org/prevention-and-diagnosis/diagnosis/hbv-blood-tests/#:~:text=HBsAg%20(Hepatitis%20B%20surface%20antigen,antigen%E2%80%9D)%20in%20your%20blood.