Particle Soot Absorption Photometer (PSAP)
Purpose of Participation
- In-situ ground-based continuous measurements of aerosol absorbing properties
Instrument description
The instrument is based on integrating plate techniques where change in optical transmission of a filter caused by particle deposition on filter is related to the optical absorption coefficient using Beer's law and a calibration transfer coefficient. Green light diode at 550 nm is used as a light source.
| Species | Aerosols |
| Method | Aerosol light absorption |
| Quantity primary | Optical extinction coefficient for absorption |
| Quantity secondary | Particle soot concentration |
| Measurement range | > few nanograms of soot per m -3 of air |
| Altitude range | NA |
| Vertical resolution | NA |
| Temporal resolution | In principle real time, integration normally performed for hour averages |
| Operation | continous |
| Precision | Depends on averaging time |
| Preliminary data | in principle next day (man power dependent) |
| Final data | one year |
Specific remarks
- Ambient p and T from POLAR 4 basic instrumentation are required to derive ambient concentrations
- Custom made instrument
References
Liousse, C., H. Cachier, and S.G. Jennings, Optical and thermal measurements of black carbon aerosol content in different environments: variation of the specific attenuation cross-section, sigma, Atmospheric Environment, Part A, 27A (8), 1203-1211, 1993.