Recent developments in instrumentaion for real-time monitoring of air emissions

A discussion covers developments in instrumentation for real-time monitoring of air emissions, e.g., CO, NO₂, and SO₂; advantages and challenges of continuous on-line monitoring over the conventional approach of sampling followed by laboratory analysis; examples of such devices, e.g., FTIR, non-dispersive IR (NDIR), or NDUV; the other approach, which is extractive devices where a sample is physically transported from the emission or process stream into an analyzer; analysis of trace concentrations at sub parts per million levels; the application of sorbent traps in air monitoring; the use of a micro-sorbent trap (referred to as a microtrap) as concentration cum injection device for continuous monitoring of VOC in gas stream; configuration of the microtrap with a gas-sampling valve; continuous nonmethane organic carbons analysis; and microtrap MS.