This Standard specifies a gravimetric method for the determination of suspended particulatematter in ambient air. Generally, the particles collected are of equivalent aerodynamicdiameter (EAD) of less than 100 µm. The upper size limit of particles collected dependsupon sampling conditions, especially wind velocity and direction.The method provides a measure of mean concentration of TSP over the sampling periodemployed.NOTES:1 Sampling is normally of 24 h duration to average out the effect of the diurnal variations inparticle levels and to enable collection of sufficient mass of particulate matter. Provided thatthe mass of the filter is determined under carefully controlled laboratory conditions, meanconcentrations of 1 µg/m3 and greater may be determined using a 24 h sampling period.2 It is possible that some particulate matter, depending upon its hygroscopicity or volatility,may alter in mass from its initial as-sampled state because of the environmental conditionsand filter equilibration procedure referred to in Clauses 7.1 and 7.8. The degree of masschange is largely due to the nature of the sampled aerosol and may vary from day to day, siteto site and seasonally.

Originated in Australia as AS 2724.3—1984.Jointly revised and redesignated as AS/NZS 3580.9.3:2003.Second edition 2015. Originated in Australia as AS 2724.3-1984. Jointly revised and redesignated as AS/NZS 3580.9.3:2003. Second edition 2015.