{"data":{"id":"us/40-cfr-1065.790","jurisdiction":"us","citation":"40 CFR 1065.790","heading":"Mass standards.","body":"(a) PM balance calibration weights. Use PM balance calibration weights that are certified as NIST-traceable within ±0.1% uncertainty. Make sure your highest calibration weight has no more than ten times the mass of an unused PM-sample medium.\n(b) Dynamometer, fuel mass scale, and DEF mass scale calibration weights. Use dynamometer and mass scale calibration weights that are certified as NIST-traceable within ±0.1% uncertainty.","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER U—AIR POLLUTION CONTROLS","PART 1065—ENGINE-TESTING PROCEDURES","Subpart H—Engine Fluids, Test Fuels, Analytical Gases and Other Calibration Standards"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-40.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:04Z","sha256":"96ecc277a18e26494462e775d2c0afe36da70a84ab78954a00d60f370afff2dd","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-1065.750","next":"us/40-cfr-1065.801"},"notice":"GroundRules: Original legal text. Not legal advice."}