Definitions / Measurements - FAQ
Definitions / Measurements frequently asked questions.
- What is the definition of VOC?
- How does PM2.5 relate to PM species such as EC, OC, SO4, NO3, PMFINE, and DIESEL-PM25?
- What are the units of NEI emissions data?
- What does an annual emissions value in the NEI represent (one year or multiple years)?
- What does "NEC" stand for in the emissions sectors?
- How are Oxides of Nitrogen (NOx) defined in the NEI?