If using the reactor to calculate SOA yields or secondary-to-primary aerosol enhancement ratios, size-dependent particle transmission calibrations should be conducted to correct for any potential particle losses. This is especially important if the mean volume- or mass-weighted particle diameter is less than 100 nm.
- Generate appropriate size-selected surrogate aerosol (e.g. ammonium sulfate, dioctyl sebacate, soot, etc.)., send the aerosol flow through the bypass line, and measure the particle number concentration downstream with a CPC.
- Then, send the aerosol flow through the reactor and repeat the measurement.
- Normalize the particle concentration measured downstream of the reactor to the particle concentration measured through the bypass line. The ratio of these measured particle concentrations is the particle transmission at that size.
- Repeat over several particle sizes that span the range of aerosol size distributions measured in aerosol aging experiments.