ID:
37

Name:
Ammonium sulfate RH 67 with ozone

Instrument:
scanning mobility particle sizer (#484)

Chamber:
Tran's big bag of air

Temperature (°C):
22

Relative humidity (%):
67

Particle composition:

• Ammonium sulfate

Particle measurement size range:
15-700 nm

Particle generation method:
atomization of a 0.3 M ammonium sulfate solution in water using N2

Date of characterization experiment:
2022-07-25

Months since calibration:

Wall loss experiment description:
The chamber was humidified to the desired RH. Ozone (150 ppb) and H2O2 (4 ppb) were injected to match ozonolysis experiments in the "terpene nighttime chemistry" set. Particles were injected, and briefly mixed with pulsed air. Then the SMPS monitored the loss rate over the course of several 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:
220725_betas.csv