FAAM CORE Particle Soot Absorption Photometer (Radiance Research)

 

The PSAP is used to measure in near real time the optical extinction coefficient for absorption which can in also be used to estimate concentrations of black carbon. The method is based on the same principle as the integrating plate, in which the change in optical transmission of a filter caused by a particles deposition is related to the optical absorption coefficient using Beer's Law. The instrument draws in air across a filter where particulate matter is deposited. The transmittence of a green (565 nm) LED light source through this medium is measured and compared to a reference cell, where the same light source is passed over the filter with no aerosol deposition. 

 

 

Below are the Radiance Research instrument manual, historic information (filter media, cable schedules etc) and TSSE. 

 

 

 

 

The data produced by FAAM in uncorrected, the document below discusses the correction techique from Bond et al (1999).  It should be noted by the user of this data that the instrument measures flow as mass flow, to correct properly volumetric flow should be used. Multiply the linear absorption parameter (PSAP_LIN) in the core data set by the calculated volumetric flow divided by the measured mass flow (3 SLPM), use this value to replace C_ss in the follwoing document. For further corrections see Tech Note 31 (166.5 kB).

 

This instrument is not currently operated on all flights, its operational status can be seen in the flight log status pages.

  

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