The HORIBA’s Ambient Air Pollution analyzers feature advanced technology, field-proven reliability with excellent sensitivity & precision at ppb levels, and hassle free maintenance. Each of these monitor, differs in their operation principle, measure single/multiple components in ambient air or diluted stack gases.
A number of these are MCERT's certified.

APHA-370 Ambient THC monitor

The APHA-370 continuously monitors atmospheric THC, NMHC, and CH4 concentrations...

APDA-371 Ambient Dust Monitor

The APDA-371 automatically measures and records airborne particulate concentration levels (in milligrams or micrograms per cubic meter) using the industry-proven principle of beta ray attenuation.