Ecotech HiVol background
High volume air samplers are used to collect samples of air-borne matter for subsequent analysis. Generally, high volume air sampling is a technique that employs a gravimetric method for the determination of suspended particulate matter in the atmosphere. The term ‘gravimetric’ implies a weight measurement.
The technique of high volume air sampling developed in the United States during the 1940's. Early “HiVols” (generic term for High Volume Air Samplers) were comprised of modified household vacuum cleaners with 100 mm diameter filters.
During the 1950's the design of high volume air samplers was altered to incorporate the use of 200 x 250 mm filters to permit continuous 24 hour sampling.
Until the 1980's the high volume air sampler was used solely to collect data on total suspended particulate matter (TSP). With the introduction of primary health-based particle standards during the 1980's many High volume air samplers were retro-fitted with PM10 Size Selective Inlets (SSI) to capture particulate matter less than 10 µm (micro-metre or micron) in diameter. The technique is known as High Volume Size Selective Inlet PM10 sampling, and monitoring is aimed at providing information on particles capable of penetrating to the thoracic region of the human body. More recently, PM2.5 concentration has been linked to adverse health effects. A PM2.5 Size Selective Inlet (SSI) is used to capture particulate matter less than 2.5 µm in diameter.
Ecotech High Volume Air Sampler
Ecotech has been designing and manufacturing High Volume Air Samplers for twenty years. Our original HiVol 2000 series can still be found in use today, which is a testiment to its reliability and low maintenance. Ecotech was one of the first manufacturers to use an inductive brushless motor, previous to its introduction the blower motor of High Volume Air Samplers needed to have its brushes replaced after only a couple of hundred hours of operation, the carbon brushes also were a source of contamination during sampling.
Ecotech's HiVol 3000 high volume air sampler was first introduced in 2002 and was the first high volume air sampler to provide true volumetric flow control and incorporate an internal datalogger capable of recording total flow, ambient pressure, temperature and wind speed and direction when fitted with an optional anemometer. It was also the first sampler to provide remote communication and data downloading capabilities.
Ecotech's HiVol 3000 high volume air sampler obtained U.S. EPA FRM approval in July 2006, Manual Reference Method: RFPS-0706-162
The Ecotech HiVol may be fitted with a TSP inlet, PM10 or PM2.5 SSI hoods. The inlets are easily interchanged if required. The inlet hoods can be easily identified - the TSP inlet is shaped like a pyramid and the SSI type is cylindrical in shape.
The airborne suspended particles that pass through the inlet are collected on a pre-weighed filter, during a pre-determined sampling period that is programmed into the HiVol by the operator. The filter collects the airborne particles for subsequent analysis. The HiVol controls the flow-rate and records the sampling duration and volume of air that has been sampled.
After the sampling period is complete, the filter is removed and re-weighed to determine the concentration and/or composition of suspended particulate matter. Concentration results are typically expressed in micrograms per cubic metre (µg/m3) of air sampled at Standard Temperature and Pressure (STP) conditions.
Acceptable levels have been established to govern the amount of airborne particulate of a particular size and composition that may pose a health hazard to humans.