Testing and Measuring Emissions
National Vehicle and Fuel Emissions Laboratory (NVFEL) Emissions Analysis
Please Note: The Code of Federal Regulations is the official source of vehicle/engine certification test procedures.
Emissions Sampling and Analysis
- This graphic shows dilution of vehicle exhaust and the flow of emission samples through analytical instrumentation. Vehicle Emissions Sampling and Analysis (JPG, 163K)
- Natural Gas Fuel Analysis
- This worksheet follows ASTM procedures for the derivation of heating value and specific gravity from a report of the mole constituents of natural gas. EPA 40 CFR Parts 86 and 600 required values are also derived. Natural Gas Fuel Properties Derivation (XLS, 121K)
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- Sample Emission and Fuel Economy Calculations
- Natural Gas FTP Emissions Derivation (PDF) (12 pp, 137K)
- Natural Gas Highway Emissions Derivation (PDF) (6 pp, 55K)
- Natural Gas Fuel Economy Derivation (PDF) (2 pp, 30K)
- NOx Humidity Correction Factor
- Humidity and NOx Humidity Correction Factor Derivation (PDF) (11 pp, 161K)
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