| abstract |
(57) [Abstract] [Purpose] To detect the deterioration of the filter used for the calibration of the color and turbidity measurement sensor. [Structure] In addition to the existing filter, a second filter is additionally installed, and the color and turbidity of the water passing through the second filter is measured, and the measured values of the color and turbidity of the water passing through these two filters are compared. By doing so, since the second filter has not deteriorated when the existing filter starts to deteriorate, it is possible to determine the deterioration of the existing filter. |