| 摘要 |
PURPOSE:To demonstrate that a total organic carbon meter has the sensitivity for measuring ultra low concentration by diluting external pure water with ultrapure water according to a ratio calculated at a sample injection control section thereby preparing a test liquid having ultra low carbon concentration. CONSTITUTION:A working curve representative of the relationship between the total carbon (TC) concentration and the output from a detector is determined for a standard liquid and held at a working curve section 30. A specified quantity of general pure water is injected to a TC oxidation reaction section and a value measured at a data processing section 13 is compared with the working curve held at the section 30 in order to calculate 31 the TC concentration of pure water. The pure water is then diluted with ultrapure water (condensate of steam produced at the reaction section) based on the TC concentration of pure water thus calculated and a ratio for diluting to a preset ultra low carbon concentration (about 50ppb or less) is calculated 32. Subsequently, the quantities of pure water and ultrapure water are calculated based on the dilution ratio and a desired ultra low concentration test liquid is prepared and injected to the TC oxidation reaction section thus demonstrating that ultra low TC concentration can be measured. |
