Comparison of Three Different Real Time Particle Measuring Instruments
The Hunter Valley in New South Wales is an area highly impacted by the effects of open-cut coal extraction. There is widespread interest in quantifying the contribution which mining and associated activities makes to particulate concentrations in the local airshed. A year long study in the Hunter at two near-mine rural sites and at two rural town sites has examined possible sources for measured particulate emissions. Critical to source identification is the determination of particulate concentrations over shorter term time intervals to establish whether changes can be related to prevailing meteorology and mining activities.
Four instruments (TEOM, OSIRIS, GRIMM, DustTrak) capable of determining fine particle concentration were deployed during the current program. The study focused on the PM10 and PM2.5 size ranges. Of these instruments the TEOM is the only instrument that provides a direct mass measurement. The other instruments use optical methods to infer particle mass and concentration. However, each of the instruments presents challenges related to the method of sampling and measurement. The TEOM, OSIRIS and GRIMM were all operated with heated inlets.
The paper presents the results of the study and comments on the potential use of each instrument to provide information of value, particularly with regard to the current regulatory environment for PM2.5. Also presented are examples where the data from the relatively rapid response instruments (1hour averaging time) have been used to investigate the sources of the particle concentrations.