The National Institute of Standards and Technology Handbook 155-2011, Weights and Measures Programs Requirements, is a Handbook for the Weights and Measures Administrator. When a weights and measures administrator makes decisions within a specific jurisdiction, it is beneficial to understand the scope of the entire system and to reflect upon methods and practices that have been tested over the years. This handbook was developed for the weights and measures administrator to be used as a reference tool. It is designed to read in sections as needed for a specific situation or to learn piece by piece about the weights and measures system as a whole.