The Sludge Judge from Nasco can be used to take accurate readings of settleable solids, 5 percent or less, in a variety of liquids to any depth. It is ideal for sewage treatment plants, chemical plants and food-processing facilities where accurate sample levels of settleable solids in non-caustic materials are needed. The unit holds approximately 3 ounces per foot. It comes in 5-foot sections of 3/4-inch plastic pipe with screw-type connectors. The top section includes a nylon rope for raising and lowering the sampler. Individual sections can be combined as required to achieve the length needed. Do not use in liquids over 165 degrees F. 800/558-9595; www.enasco.com.