Impactor design standardized by IIT Kanpur for monitoring Sub micron particulates (size less than 1 micron)
Almost two decades ago it was realized that all SPM may not have health implications for humans though it may impact vegetation and cause soiling of surfaces and be a general nuisance. The characteristics, sources, and potential health effects of larger (above 10 microns in size) or "medium" fraction particles (from 2.5 to 10 micrometers in diameter) and the smaller or "fine" particles (smaller than 2.5 micrometers in diameter) are very different. Coarse and medium size particles come from sources such as windblown dust from the desert or agricultural fields, the dust kicked up on unpaved roads by vehicle traffic, crushing and grinding activities in industries and also from soot and smoke emissions.
Fine particles are generally emitted from activities such as industrial and residential combustion and from vehicle exhaust. Fine particles particularly sub-micron ultra-fine particles also called secondary particles are also formed in the atmosphere when gases such as sulfur dioxide, nitrogen oxides, and volatile organic compounds, emitted by combustion activities, are transformed by chemical reactions in the air.
Recent studies sponsored by US EPA have concluded that the sub-micron “ultra fine” particles, which penetrate deeply into the lungs, are more likely than coarse, medium or even fine particles above 1.0 micron in size to contribute to the health effects (e.g., premature mortality and hospital admissions) found in a number of recently published community epidemiological studies at concentrations that extend well below those allowed by the current PM10 or even PM2.5 standards.
To protect communities exposed to particulate matter, US EPA and other agencies in the developed world are now adopting new standards for monitoring the sub-micron or PM1 levels in addition to the PM10 or PM2.5 standards already in use. Envirotech’s APM 577 Particulate Sampler has been developed to fill this critical need.
The APM577 is a manual method for sampling very fine sub-micron particulates (PM1 fraction). This sampler is based on impactor design standardized by Indian Institute of Technology, Kanpur.
The air enters in the system through an omni-directional inlet designed to provide a clean, aerodynamic cut point for particles. The air sample & fine particulates exiting from the PM1 impactor are passed through a 47 mm diameter PTFE filter membrane that retains the sub-micron PM1 dust.
The sampling rate of the system is held constant at 10 LPM by a suitable critical orifice. A dry gas meter is incorporated to provide a direct measure of the total air volume sampled. Time totalizer provides information on actual run time of sampling. An electronic timer is also provided to start the sampling and shut off the sampler as per requirement of the sampling, thus eliminating the need of presence of man power at site.
A provision is available to attach a Gaseous Sampling Attachment, to collect sample for gaseous pollutants simultaneously.
The system is provided with a brushless, continuous rated induction motor driven suction pump which eliminates electromagnetic interference (EMI) in gadgets like TVs, which sometimes hinders operation of air samplers in residential areas and is immune to voltage fluctuations.
APM577 sampler is housed in a compact, light, robust & weather proof cabinet made of aluminum.
- Totally indigenous (designed, developed and made in India)
- Uses a maintenance-free brush-less pump with low noise.
- Lower sampling rate of 10 LPM reduces filter choking even in areas having high FPM levels.
- Provision for attachment to sample gaseous pollutants simultaneously.
- By locating impactor & filter holder assembly separate from all power dissipating components, the system ensures that the temperature of filter remains close to the ambient temperature and there is no chance of losing volatile fraction of PM1.
- Compact and portable for convenient field operation.
Omni-directional air inlet with PM1 separation through an impactor designed and perfected by IIT Kanpur
Constant sampling rate of 10 liter per minute, unaffected by voltage fluctuation maintained by critical orifice system
Filter holder designed to accept any standard 47 mm diameter Teflon membrane
Dry Gas meter records the total air volume sampled
Automatic sampling control
24 hour programmable timer is provided to automatically start and shut off sampler as per requirement
Single phase AC 220 volts, 50 Hertz supply. Sampler unaffected by +/- 10% fluctuation in supply voltage.
20 kg (approx.)
(W X D X H) in cm. with Impactor & Inlet: 35 X 26 X 87, without Impactor & Inlet: 35 X 26 X 58
Download PDF Below.