Envirotech initially introduced the APM 451 Respirable Dust Sampler based on CSIR/NEERI knowhow. Withmore than 1000 instruments of this model currently operating in the field, the APM 451 forms the backbone of the National Ambient Air Quality Monitoring Network and is in widespread use by Consultants and a wide spectrum of industries. Based on their feedback, the APM 451 system was upgraded to APM 460.
The APM 460 sampler uses an improved cyclone (with sharper cutoff) to separate the coarser particles (>10 microns) from the air stream before filtering it on the 0.5 micron pore-size filter allowing a measurement of bothTSP and Respirable fraction of Suspended Particulate Matter (SPM).

Flow Rate :	0.9 – 1.4 m3 /min free flow.
Particle Size :	Particles of 10 microns & below collected on Filter Paper holder. SPM bigger than 10 microns collected in a separate sampling bottle under the cyclone.
Sampling Time :	28 hours (maximum)
Sampling Time :	Record 0 to 9999.99 hrs. recorded on a Time Totalizer.
Automatic Sampling :	24 hrs programmable timer to automatically shut off the system after pre set time interval.
Power Requirement :	Nominal 220 V, Single Phase, 50Hz AC mains supply.
Size & Weight :	430 x 320 x 930mm., 45Kg