| 摘要 |
PURPOSE:To remove detection errors by connecting a pair of sampling tubes for sampling a sample on the upstream and downstream of a filter to a single concentration detector to perform a measuring with a switching. CONSTITUTION:Sampling tubes 5a and 5b are connected in branch to pipings on upstream and on downstream of a filter 1 to be measured in the filtration efficiency. A single concentration detector 10 is connected in common to the sampling tubes 5a and 5b. Then, passage changeover means 9a and 9b are provided at the connection thereof to change over the passage to connect one sampling tube selectively to the detector 10. Therefore, as measurement is done with the same detector 10, detection error can be eliminated as caused based on deviation in the detection property possible when a separate detector is provided. |
