AS NZS 3580.9.3:2015 pdf free.Methods for sampling and analysis of ambient air Method 9.3: Determination of suspended particulate matter—Total suspended particulate matter (TSP)—High volume sampler gravimetric method.
4 PRINCIPLE
Ambient air is drawn at a constant flow rate through a prepared filter via a TSP inlet, which effectively acts as a hood to prevent precipitation and debris from falling onto the filter.
The TSP is collected on a prepared filter mounted in the high volume sampler filter holder and subsequently weighed (gravimetric method). The TSP concentration is determined by dividing the mass of collected particulate matter by the sample volume, which is calculated from the sample duration and either the average or totalized flow rate.
5 APPARATUS
5.1 High volume sampler
The high volume sampler shall consist of a filter holder, a motorized fan, a shelter, an air flow measuring device and an elapsed time meter that measures the actual sampling duration to within ±1% U95. Samplers shall have a programmable time clock capable of controlling operation of the sampler to within 2% of’ the selected time period.
NOTE: A seven-day time clock is useful for operating the sampler on pre-set days in unattended locations. A six-day time clock may he used when the sampler is required to operate on a six-day cycle (sampling 24 hours every sixth day). Battery backup for the programmable time clock is preferable to avoid incorrect sampling times, and/or the installation of an hour run meter to verify the sample duration.
Automatic flow controlled samplers shall be designed to maintain a fixed flow rate despite a build-up of particles on the filter by either—
(a) adjustable flow control and a method for automatic flow adjustment to maintain a constant flow rate; or
(b) be constructed in such a way that only a constant and known air flow rate can pass through the filter, irrespective of variations in power supply voltage, power supply frequency or filter resistance normally experienced on a routine basis.
NOTE: If the ambient air temperature or barometric pressure changes, a mass flow controlled high volume sampler changes the volumetric flow to achieve a constant mass flow rate, whereas the volumetric flow controlled sampler maintains a constant volumetric flow rate, independent of temperature changes.AS NZS 3580.9.3 pdf download.