Two wet/dry atmospheric deposition sampler types were compared for 1 yr. The resistance required to open each of ten collectors was determined. Additionally, the opening and closing history of each sampler was recorded using a microdatalogger with a resolution of 1 min. The frequency distribution of amount of time that a collector was open was used to evaluate the comparability of opening and closing of each collector. Weekly amounts of rainfall for each of the collectors was used to determine the efficiency of collection as compared to a Belfort 5–780 weighing rain gauge. The performance of a collector as determined by the efficiency of collection and also by the distribution of frequencies of times that a sampler was exposed to precipitation were statistically different for the different sampler configurations. Disclaimer. Publication, does not signify that the contents necessarily reflect the views and policies of Department of the Army and the US Military Academy, nor does mention of trade names or commerical products constitute endorsement or recommendation for use. Not subject to copyright restrictions, work of US Government.