Mahabal enviro engineers [meepl] is an iso-9001:2000 certified company for environmental services and structural steel fabrication/erection, etc. Ambient air quality monitoring is done to measure the common air that human beings breathe anywhere or at workroom environment. Depending on the location chosen, the standards of national ambient air quality [naaqs] or work area [factory/industrial battery limits] environment standards [such as osha/stel/twa] are applicable. The respirable dust sampler [rds] is modified high volume sampler [hvs] with capability to separate the below 2.5 or 10 micron dust respectively. The design of the rds has to be developed and certified by the recognised institute. The duration of sampling has to match with the one specified in the standard being used for comparison. Depending on the concentration of various pollutants, the sampling duration may have to be reduced to shorter interval. As such the monitoring may be continued for 24 hours, by changing the absorbing solutions after every 8 hours. The average daily results can be calculated for comparison. Gaseous pollutants are analysed by standard methods in the laboratory. Sampling rate for respirable particulate matter [rpm]/suspended particulate matter [spm] has to be minimum of 1000 ltr/min and periodic adjustment may have to be done or the filter paper has to be changed at shorter interval. The sampling rate may fall below minimum due to heavy pollution load and therefore clogging of filter paper. The machine requires 230 v supply and the motor is dc type. It is not of flameproof type and hence precautions are to be taken while sampling in prohibited area. During operation, the noise level is around 65 db 2 m away from the rds/hvs sampler.
