---
kind: "section"
citation: "40 C.F.R. § 1065.790"
title: "40"
number: "1065.790"
heading: "Mass standards."
url: "https://uscodex.org/cfr/40/1065.790"
---

# §1065.790. Mass standards.

- (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.
- (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.

## Notes

### Amendments

[88 FR 4687, Jan. 24, 2023]

### Authority

Authority: 42 U.S.C. 7401-7671q.

### Source

Source: 70 FR 40516, July 13, 2005, unless otherwise noted.

### Amendments

[88 FR 4687, Jan. 24, 2023]