An exhaust gas analyser or exhaust carbon monoxide analyser is an instrument for the measurement of carbon monoxide among other gases in the exhaust, caused by an incorrect combustion, the Lambda coefficient measurement is the most common.

A residual gas analyzer is a small and usually rugged mass spectrometer, typically designed for process control and contamination monitoring in vacuum systems.

An infrared gas analyzer measures trace gases by determining the absorption of an emitted infrared light source through a certain air sample.