Envirotech introduced the APM 451 Respirable Dust Sampler based on CSIR NEERI knowhow. The system was upgraded to APM 460 in 1997. The APM 460 sampler uses an improved cyclone with sharper cutoff (D50 at 10 microns) to separate the coarser particulates from the air stream before filtering it on the glass microfibre filter. By using the APM 460, measurement of Respirable Particulate Matter can be done accurately and TSPM can also be assessed by collection of dust retained in the cyclone cup.

Lockable casters for field convenience.

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.
Power requirement :	Nominal 220 V, Single Phase, 50Hz AC mains supply.
Size & Weight :	430 x 320 x 930mm., 45Kg