Measuring emissions from stacks is challenging due to accessibility and safety concerns and requires techniques to address a broad range of conditions and measurement challenges. One way to facilitate such measurements is to build an instrument package and then use a crane to hold the package over the emissions source. Here we describe such an instrument package that is used to characterize both wet droplet and dried aerosol emissions from cooling tower spray drift. In this application, the instrument package characterizes the velocity, size distribution, and concentration of the wet droplet emissions and the mass concentration and elemental composition of the dried PM2.5 and PM10 emissions. Subsequent papers will present and analyze the wet and dried emissions from individual towers.