Which of these is NOT a piece of sampling equipment that needs proper cleaning?

The selection of paper towels as not being a piece of sampling equipment that requires proper cleaning is accurate because paper towels are generally considered disposable items. Unlike automatic samplers, graduated cylinders, and buckets, which are utilized in the collection and measurement of fluid samples and require thorough cleaning to prevent contamination of future samples, paper towels are intended for single-use. Their purpose is primarily for drying or wiping surfaces, and they do not serve as equipment that is involved in the sampling process itself. Consequently, they do not necessitate the same level of cleaning protocols that apply to reusable sampling tools.