Aurora 2000 PM2.5 Nephelometer — manual correction factor configuration
In applications where the aerosol chemistry is stable, a correction factor can be manually entered which then provides excellent results with minimal maintenance and a high degree of correlation.
Aurora 2000 automatic correlating PM nephelometer configuration
In applications where aerosol chemistry is subject to change, a correction factor derived from manual sampling may be unreliable. In this case the Aurora 2000 may be connected directly to a PM2.5 compliance monitor, either the Acoem Spirant BAM or the Met One BAM 1020, in order to monitor and log PM hourly averages generated by the BAM (PMBAM). These hourly averages are compared to the Aurora’s hourly average scattering coefficient (σscat) and a scattering to PM coefficient factor (σscat/PM) is calculated.
This factor is then applied to the next hour of 1 minute scattering coefficients measured in order to determine a 1 minute average for PM concentrations (PMaurora).
The derived correction factor can also be used to determine changes in aerosol sources through deviations in light scattering from the expected values.
This configuration of the Aurora 2000 nephelometer provides the following parameters:
- US EPA compliance data for PM2.5 measurement
- Scattering coefficient (σscat)
- BAMPM averages – 1 hour average only
- Corrected real time 1 minute PM concentrations PMaurora
- Sample temperature, relative humidity & barometric pressure.