Particle Loss Characterization #27 - 2020-09-21


Ammonium sulfate

scanning mobility particle sizer (#484)

Tran's big bag of air

Temperature (°C):

Relative humidity (%):

Particle composition:

  • Ammonium sulfate

Particle measurement size range:
14 - 670 nm

Particle generation method:
Atomization of 0.06 M ammonium sulfate solution

Date of characterization experiment:

Months since calibration:

Wall loss experiment description:
H2O2 and O3 were injected concurrent with ammonium sulfate atomization, to mimic the a-pinene ozonolysis experiments. After injections the chamber was briefly mixed with pulses of air and allowed to sit undisturbed for 6.5 hours.

Wall loss rates calculation method:
The loss of each particle size was binned in Matlab and an exponential fit was performed to extract the first order loss in per minute.

Frequency of particle loss experiments:
As needed for particle type and RH (doesn't change much)

Wall loss correction description:
SMPS data from SOA experiments select the particle loss file that closely match the particle type (pure organic, pure AS, mixed AS/org, or other) and then each size bin is corrected for the loss frequency. We check that the ~ 1 hour period that the particles equilibrate in the chamber prior to experiment start is corrected to zero loss (flat line) from the appropriate wall loss file.

Link to supplemental information:

Additional notes:

Characterization data file:

ID Name Start date Experiment Category Reaction Type Reactant(s) Oxidant Name Temperature Humidity Type of Seed RO2 Main Fate Data Sets (count) Actions