Fuel-flow calibration.

(a) Calibrate fuel-flow meters upon initial installation. Follow the instrument manufacturer's instructions and use good engineering judgment to repeat the calibration. (b) [Reserved] (c) You may remove system components for off-site calibration. When installing a flow meter with an off-site calibration, we recommend that you consider the effects of the tubing configuration upstream and downstream of the flow meter. We recommend specifying calibration reference quantities that are NIST-traceable within ±0.5% uncertainty. [70 FR 40516, July 13, 2005, as amended at 86 FR 34541, June 29, 2021; 88 FR 4674, Jan. 24. 2023]