MAO/CPC/S1 - Environmental, Instrument
A suspected obstruction in the capillary of the cpcu (TSI 3776) caused an error in the capillary pressure drop measurement. This type of problem causes the instrument to report flow rates (and therefore particle number concentrations) higher than are measured with a flow meter. This reduced flow rate and the associated error in counting causes the instrument to report values lower than that actual atmospheric particle number concentration.
Compare against cpcf and total SMPS data for this time period.