ID:
32

Name:
General Jimenez Chambers Particle Wall Loss Characterization

Instrument:
TSI Scanning Mobility Particle Sizer (#376)

Chamber:
1-White (1W)

Temperature (°C):
20

Relative humidity (%):
0

Particle composition:

• Experiment-dependent seed, otherwise typically DOS or Ammonium Sulfate.

Particle measurement size range:
10-600 nm

Particle generation method:
- TSI Collison Nebulizers (TSI 3076), dried with Nafion Drier and charge neutralizer (TSI 3077A) - Or for organic liquids, a custom-built evaporation/condenser generator modeled after "Sinclair, D.; La Mer, V. K. Light Scattering as a Measure of Particle Size in Aerosols. The Production of Monodisperse Aerosols. Chem. Rev. 1949, 44 (2), 245−267."

Date of characterization experiment:
2021-11-04

Months since calibration:
0

Wall loss experiment description:
Particles are generated (see generation methods) and dried and neutralized if needed (for aqueous solutions Collision-type atomizer). Chamber is placed in "batch mode" meaning no flow in or out. Particle concentrations are monitored with an SMPS with 2-min scans for 45-60 minutes. Care is taken to not touch or rub the Teflon bag to avoid inducing static charges during experiments, which could change the particle loss rates.

Wall loss rates calculation method:
Integrated particle volume is calculated as a time series in custom IGOR Pro software. A first order exponential decay coefficient is fit to the data with Igor Pro.

Frequency of particle loss experiments:
Typically whenever seeding an experiment. Otherwise at least once for a series of experiments without seeds.

Wall loss correction description:
First-order integrated particle volume correction. Integrated volume particle loss coefficient applied to integrated mass or volume time series to correct for chamber partile losses. SOA experiments corrections assume the seed plus condensed SOA decay at the same rate through the experiment.

Link to supplemental information:

Additional notes:
Typical wall loss coefficients are 5e−5 s−1, which corresponds to ~15% volume concentration loss in 1 h. See description and application here: https://www.nature.com/articles/s42004-019-0200-x

Characterization data file:
Jimenez_CUBoulder_GeneralParticleWallLoss_CharacterizationCorrection.csv