Other examples of Particulate Monitoring for dusts and vapors
An overview of other forms of particulate monitoring  
Sources of pollution in the atmosphere
 Particulates in the air around us are just as much of a potential problem in the environment as they are in the workplace. Guidelines published by the Environmental Protection Agency (EPA) in the USA suggest two levels of interest in sampling air for suspended particulates with cutoff sizes at 10 and 2.5 microns respectively. These are referred to the PM10 and PM2.5 (Particulate Matter) fractions and can be achieved by using inline Polyurethane Foam (PUF) Filters before the collection filter itself. The primary causes of such particulate sizes of interest are from bi-products produced by the internal combustion engines, power plant emissions and such things as forest fires. The PM2.5 size particulates are particularly dangerous as the size is small enough to get right down into the breathing passages where they are difficult to dislodge. The Microdust pro monitor in the medium term environmental enclosure allows 24 hour measurements to be undertaken in conjunction with a suitable power supply and pump and filters.  Comprehensive remote operation is possible using a wide range of telemetry options.
 
example of typical source of environmental particulates
Benefits of a real time display
All current applications using personal sampling pumps for monitoring vapors and particulates produce an average concentration level over the whole of the duration of the measurement. As such there is no evidence of when the concentration levels were high and when they were low. It can be extremely useful to collect time history information about the temporal distribution of levels during a run in order to study the processes that caused certain significant high values and hence must be tackled first in any control scheme. Data logging particulate concentrations at regular time intervals and storing these values in memory allow the user to visually reproduce a trace of levels showing what happened and at what time. The Microdust pro monitors such levels and shows the changing concentration on the built in display as it occurs. This is invaluable for measurements of high concentrations that only last for short periods of time during the run. Such examples include pharmaceutical companies that may mix powders in open vats during a manufacturing process.
 
example of the real time screen on the Microdust pro monitor
Process control applications
Many industrial processes require a constant monitoring of concentration levels for such applications as toxicology laboratories investigating the affects of certain chemicals on animals. Legal requirements exist to test a wide variety of potentially toxic substances by exposing animals to higher than normal concentrations of products under closely controlled laboratory conditions. The Casella Microdust pro real time particulate monitor can be installed in a fixed wall mounted system with any vapor drawn through the optical chamber continuously to measure the concentration. An output is taken to a strip chart recorder to provide relevant authorities with a permanent report that can be correlated with the predicted vapor concentration produced by the mixing system. A built in purge pump is included to keep the optical parts of the transducer clean to maintain a good quality signal. The pump and Microdust pro monitor are powered from a mains supply through a suitable step down transformer for long term operation. Manufacturing of such products as cement powder or lead acid batteries can also produce high levels of polluting dusts that may escape into the atmosphere. The Casella Microdust pro Process control system is an ideal tool to monitor the manufacturing process and warn of high concentration levels in exhausts or filter systems.
 
continuous dust monitoring during the production of cement at a mill
Stack sampling
This technique refers to measuring the concentration levels in exhaust stacks such as chimneys on power stations or lead processing plants. If levels get too high then a breach of local pollution limits may occur. Adapters exist to place in the stack to pass a representative air sample through the real time monitor. The concentration level is continuously monitored and an output signal can be obtained to link to an alarm system so that the offending process can be temporarily paused or halted until the reason for the rise in level has been satisfactorily investigated and dealt with. The Casella Microdust pro is used with the stack sampling kit for this task to provide the real time output alarm signal.
example of emissions from a power station chimney stack

page last updated - Monday January 14, 2008