Apparatus and methods for creating deposits of uniformly spaced or uniformly overlapping droplets of selected chemicals where each droplet has an a priori known amount of the selected chemical or chemicals is taught (including biological and microbial materials). In some embodiments the deposits may be used as samples of different but known concentrations that may be used to calibrate spectroscopic inspection instruments to enable such instruments to not only provide identification in situ of unknown materials but also to provide calibrated and traceable surface concentrations of such materials. In some embodiments, such calibrated instruments may be used in enhanced processes for validating the cleanliness of manufacturing surfaces such as surfaces of equipment used in the preparation of pharmaceuticals, food, or semiconductor devices. Such instruments may be used to ensure adequate purity, or non-contamination, of surfaces of products themselves or packaging materials or of locations where such products will be used. Such calibrated instruments may also be useful in detecting cleanliness of non-manufacturing surfaces where contamination may be of concern, whether they be public or private spaces such as laboratories, restaurants, airports, satellites or other spacecraft. In some embodiments, such instruments may range from deep UV instruments to far infrared instruments or beyond.