# Cryogenic liquid meters · 2.5 · 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 Cryogenic liquid meters · 2.5 · 3.37. Mass Flow Meters, device or commodity is Cryogenic liquid meters; accuracy class is 2.5; acceptance tolerance (new or newly repaired device) is 1.5 %; maintenance tolerance (device already in service) is 2.5 %; special test tolerance is 2.5 %, verified against its source on 2026-08-20. - **Device or commodity:** Cryogenic liquid meters _(verified: appears in the quote below)_ - **Accuracy class:** 2.5 _(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):** 2.5 % _(verified: appears in the quote below)_ - **Special test tolerance:** 2.5 % _(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 > 2.5 - Cryogenic liquid meters 1.5 % 2.5 % 2.5 % - Liquefied compressed gases other than LP Gas ## 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/).