Abstract:Ultrasupercritical requires high quality water vapor.SiO2 contains is very low. The tolerance of existing spectrophotometry method to measure SiO2 content is very big. So that, it is difficult to monitor the varying of SiO2 content. Take a 1050MW ultracritical onethrough unit as example, this paper examined the tolerance causes from drug, method, environment and instrument. Test operation and procedure was improved. SiO2 mass concentration accuracy was significantly increased.

关键词：二氧化硅, 分光光度法, 准确度