frame supported a plastic intake nozzle and swung open to permit the plastic container to be removed. When the head was closed, the end of the nozzle extended slightly into the mouth of the container and the container sealed against a gasket. An adjustable rubber stop at the rear of the sampler held the container in place. The perforations in the container were 0.75 in diameter holes arranged in three partial rings of six holes each on the underside of the container at different lengths. In addition, there was a large opening in the side of the container just below its neck. During sampling, this opening was covered with a loose fitting plastic sleeve. For sampling, a collapsed, pre-shaped, flexible, plastic bag was placed inside the rigid container.The neck of the flexible bag was stretched over the neck of the rigid container, and the whole unit placed into the sampler. The sampler was of limited use at stream velocities above 3 ft/sec, was cumbersome to operate, and had an unsampled zone of approximately 18 inches.
Szalona (1982) conducted another investigation into the use of a bag sampler. His approach was to modify the U.S. D-77 sampler. The sampler was equipped with a 3-liter plastic bottle, nozzle cap and nozzle, and used a commercially available food storage bag. Holes were drilled in various locations of the bottle to enable quick flooding of the bottle. Various combinations of vents and deflectors were added to the U.S. D-77 sampler to facilitate isokinetic sampling. The sampler had limited use at