subpart_subject: "Engine Fluids, Test Fuels, Analytical Gases and Other Calibration Standards"
section_number: "1065.790"
section_subject: "Mass standards."
cfr_reference: "40 CFR 1065.790"
title_name: "Title 40"
title_subject: "Protection of Environment"
parts_covered: "Part 1060 to End"
revised_date: "Revised as of July 1, 2019"
publication_date: "As of July 1, 2019"
contains_description: "Containing a codification of documents of general applicability and future effect"
publication_info: "Published by the Office of the Federal Register National Archives and Records Administration as a Special Edition of the Federal Register"
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(a)PM balance calibration weights. Use PM balance calibration weights that are certified as NIST-traceable within 0.1% uncertainty. Calibration weights may be certified by any calibration lab that maintains NIST-traceability. Make sure your highest calibration weight has no greater than ten times the mass of an unused PM-sample medium.