AS/NZS 3580.9.13:2022 pdf – Methods for sampling and analysis of ambient air Method 9.13: Determination of suspended particulate matter- PM2.s continuous direct mass method using a tapered element oscillating microbalance monitor
AS/NZS 3580.9.13:2022 pdf – Methods for sampling and analysis of ambient air Method 9.13: Determination of suspended particulate matter- PM2.s continuous direct mass method using a tapered element oscillating microbalance monitor.
5.11 Zero noise check particle filter
A filter fitted to the instrument sample inlet during zero noise checks. The filter media shall have a minimum collection efficiency of 99.95 % for particles of 0.3 pm EAD and above and have negligible pressure drop at the operating flow rate.
The sampling site shall be selected in accordance with AS/NZS 3580.1.1. Where the sampling site does not conform to a requirement of AS/NZS 3580.1.1, this shall be clearly stated in the test report.
Installation of the TEOM and FDMS unit shall be performed in accordance with the manufacturer’s instructions. When installing the TEOM and FDMS unit, the following factors should be taken into account:
(a) The TEOM with FDMS unit is designed to be bench mounted due to the height of the FDMS tower. Placing the instrument Ofl a vibration isolated bench may be beneficial to reduce influences from other instruments.
Ensure there is adequate clearance on the shelter roof to accommodate the tripod supporting the PM10 size selective inlet and PM2.5 particle size separation device.
(c) Ensure the sample tubing from the size selective inlet to the top of the FDMS inlet forms a straight vertical line to avoid transverse stress on the sample tube connectors which could cause leaks.
(d) For the isokinetic flow splitter to correctly partition the incoming flow into the main and bypass flows, position the top of the inner sample tube (carrying the PM2.5 fraction flow) 150 mm ± 10 mm from the top of the flow splitter.
(e) Ensure adequate clearance around the TEOM to allow maintenance, repairs and filter changes.
(f) Provide sufficient clearance between the top of the FDMS unit and the ceiling of the monitoring shelter to allow for FDMS dryer and valve servicing. Inserting a short section of flexible conductive rubber tubing in the sample line between the top of the FDMS unit and the ceiling will permit removal of the dryer without having to remove the rooftop inlet assembly. If flexible tubing is used, the gap in the rigid tubing should be no larger than 35 mm to prevent the flexible tubing collapsing during leak checks.
NOTE Inclusion of a flexible section in the sample line will also provide harmonic isolation of the TEOM during strong winds and during monitoring station maintenance activities which require operators to work on the roof.
Insulate all exposed tubing inside the monitoring shelter and direct air conditioning vents away from sample lines and the TEOM to avoid condensation in the sample tubing under high humidity conditions, or loss of volatile particulate matter components due to inadvertent heating of sample lines above the FDMS tower.
Ensure the sample inlet tube is properly grounded to avoid static charge build-up that could lead to measurement errors. The difference in potential between the bottom of the inlet tube and the TEOM chassis should be checked to confirm that the electrical resistance is less than 5 Li
(i) If the vacuum pump is to be located further than 5 m from the TEOM, the tubing provided should be replaced with larger diameter tubing to minimize vacuum losses.
Consideration shall be given to equipment protection against excessively high or low temperatures. High temperatures may permanently damage sensitive electronic equipment while low temperatures may cause condensation to form in sample lines, which can be drawn into the monitor resulting in permanent damage.
TEOMs shall be housed in an air-conditioned monitoring station or other appropriate shelter maintained at a constant temperature within the range 20 °C to 30 °C, not deviating from the set point by more than ±3 °C.