ID:
27

Name:
Ammonium sulfate

Instrument:
scanning mobility particle sizer (#484)

Chamber:
Tran's big bag of air

Temperature (°C):
22

Relative humidity (%):
5

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:
2020-09-21

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:
Wall_loss_200921_AS_dry.csv