Table 1.

Sensor Data Adjustment Parameters: Defendable and Questionable

defendable parameters

questionable parameters

• relative humidity, for which measurement artifact has been established • temperature, for which measurement artifact has been established • other gases for which cross-sensitivity has been established • elapsed time since manufactured or deployed, if aging has been demonstrated to cause change in sensor response • accessory measurements indicating aerosol refractive index, for pm sensors • autozero data, if equipped to self-zero • monitors in close proximity, if established to have comparable data under specific conditionsa

• wind speed or direction • gases for which no cross-sensitivity is indicated • data from neighboring monitors (reference-grade or sensor) that are not proven as suitable reference pointa • local emission information or surrogates for emissions (e.g., traffic patterns, population density) • temporal factors other than elapsed time of use (e.g., time of day, day of week) • atmospheric mixing height • location relative to sources (e.g., proximity to a road)

^aThis is a subject of needed research and likely location-specific, as well as pollutant-specific.