The Filter Judge is a tool that allows a surface water treatment plant operator to quickly and accurately take a core sample of the filter media without having to take the filter cell out of service. The operator simply inserts the tool into the filter cell at the beginning of a mild backwash cycle. The fluidized media is captured in the tool and withdrawn for inspection. The depth of each layer of sand and anthracite can be easily determined. The amount of interface between layers can also be determined, as well as the presence of mudballs in the media.
The handy ruler attached to the side of the outer tube allows quick visual inspection of the media depths. The media can then be returned to the filter or can be dropped into a sample bag so that the operator can send it to a lab for analysis of uniformity coefficient and effective size.
An operator can take a dozen or more samples with the Filter Judge in the same amount of time that it would take to drain the filter and dig a single hole in the conventional way of testing media.