# Compressed natural gas as a motor-fuel · 2.0 · 3.37. Mass Flow Meters — How far off a US fuel pump, LPG meter or EV charger is allowed to be (NIST Handbook 44)

For Compressed natural gas as a motor-fuel · 2.0 · 3.37. Mass Flow Meters, device or commodity is Compressed natural gas as a motor-fuel; accuracy class is 2.0; acceptance tolerance (new or newly repaired device) is 1.5 %; maintenance tolerance (device already in service) is 2.0 %; special test tolerance is 2.0 %, verified against its source on 2026-08-20.

- **Device or commodity:** Compressed natural gas as a motor-fuel _(verified: appears in the quote below)_
- **Accuracy class:** 2.0 _(verified: appears in the quote below)_
- **Acceptance tolerance (new or newly repaired device):** 1.5 % _(verified: appears in the quote below)_
- **Maintenance tolerance (device already in service):** 2.0 % _(verified: appears in the quote below)_
- **Special test tolerance:** 2.0 % _(verified: appears in the quote below)_
- **Handbook 44 section:** 3.37. Mass Flow Meters _(verified: appears in the quote below)_
- **Edition:** 2026 _(verified: appears in the quote below)_

## What the source says

> 2.0 - Compressed natural gas as a motor-fuel 1.5 % 2.0 % 2.0 % - All other hydrocarbon gases and any other hydrocarbon gas/air mix applications not shown in the table

## Source

- https://www.nist.gov/document/2026-nist-handbook-44-section-337

Last verified: 2026-08-20. Review by: 2027-08-20.
Part of [How far off a US fuel pump, LPG meter or EV charger is allowed to be (NIST Handbook 44)](https://referencesource.org/motor-fuel-dispenser-measurement-tolerances-nist/).