In the United States this service is an important mission of the National Bureau of Standards. 在美国，这种服务是国家标准局的一个重要职责。
For some research purposes and possibly for referee work, analyzed primary standards may be obtained from the U.S. Bureau of Standards. 对于某些研究工作和仲裁工作，可以从美国标准局获得经过分析的一级标准物。
