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NEED

Monitoring of stack and vent emissions is now becoming an essential requirement not only for large but even the medium and small industrial units. There has also been a growing realisation that gaseous pollutants, chemical fumes and fine mists are much more hazardous than mere particulate, ash and dust. In many industrial units e.g. Sulphuric Acid plants, Caustic Chlorine Units etc., accurate and isokinetic sampling for total suspended particulate matter is not as critical as frequent and reliable monitoring of hazardous chemicals present in the emissions as gases / fumes. Handy stack sampler APM 620 has been developed to provide a simple, sturdy, reliable and cheap sampler for such situations. It is manufactured in accordance with the specifications of Central Pollution Control Board and other international regulatory agencies.

REQUIREMENTS

The measurement of gas borne contaminants in a duct or stack / chimney can be done either by insitu measurement of the total gas stream, most often by light scattering or absorption techniques or by extractive sampling method where by a small stream of representative sample is drawn to determine contaminant concentration. The most common and widely used world over method is extractive sample method or grab sampling technique. Grab sampling technique is also often treated as the reference standard method. Another advantage of a grab sampling technique is that it is not restricted to a specific pollutant. The same system with different reagents may be used for a variety of pollutants and over different ranges of concentration.

Envirotech APM 620 is one such grab sampler which can monitor Suspended Particulate Matter (SPM)  and any water soluble gaseous pollutants like SO₂, NO_x, H₂S, CS₂, HF etc.

PORTABILITY FOR ROUTINE SAMPLING

Only repeat and frequent monitoring can give a true insight into the emission characteristics and therefore the Pollution Control Boards, all over the country, are now laying emphasis on emission data collected more frequently rather than one or two very precise grab values. It is thus more important to have a simpler and handy device, which can be used often with ease and convenience, rather than a bulky and cumbersome system. Envirotech APM 620 is an extension of our APM 610 series of stack sampling systems. The operating principle is simple, it entraps and absorbs various gaseous pollutants like SO₂, NO_x, HF, Cl₂ , H₂S, CS₂, NH₃ etc in suitable reagents, which are analysed subsequently by simple wet chemistry methods to determine the concentrations of specific pollutants. The SPM is collected as usual over a filtration thimble.

ACCESSORIES

Many useful accessories have been developed with this system to allow users to monitor emissions in various conditions like a HEATED PROBE which allows sampling of flue gas containing high moisture, CYCLONE for high dust content concentration to avoid choking of thimbles as in cement plants, FLUORINE KIT for monitoring gases containing Fluorine / Fluorides etc., CARBON MONOXIDE BOTTLE to collect CO samples in high CO conditions as in Carbon-black plants and DG sets, EXTENSION VACUUM HOSES for sampling ports located at a distance, DIFFERENTIAL DENSITY MANOMETER for monitoring velocities in low velocity conditions as in natural draft boilers, etc., making the APM 620 a versatile instrument.