DustDisc samples can be measured for ‘settlement’ AAC% and EAC% and dust mass. As with the directional samples this is reported as the total for the sampling interval and the daily rate.

The expression ‘nuisance dust’ typically relates to the visual impact of dust settlement, and is normally generated by dust in flux. The effect caused by dust nuisance is often measured as EAC% (Effective Area Coverage) and there are ‘custom and practice’ nuisance criteria for EAC and deposited dust mass.

The DustDisc enables dust settlement monitoring with the same criteria as for flux monitoring. The settlement data may be used in conjunction with the directional data – for example by considering different AAC (Absolute Area Coverage) to EAC ratios to assess the significance of dust from different directions.

Samples can also be assessed using Beaman and Kingsbury, (1981) criteria: (0.5% EAC/day is considered to lead to “possible complaints”; 2.0% EAC/day to lead to “probable complaints” and 5.0% EAC/day may lead to “serious complaints”).

New sticky pads have been developed to provide samples for gravimetric (mass) and other analyses. We are currently undertaking co-locational gauge testing trialing our DustDisc alongside a Frisbee-type monitor to compare their sampled deposition rates. Meanwhile, dust mass settlement rate can be calculated using the approximation method developed by Beaman and Kingsbury (1984).

The new sticky pads will also allow samples to be readily analysed for dust grading and mineralogy (as well as chemistry, which we already provide).