Stack monitoring often referred as air monitoring of emission point are typically performed on any air pollution control system such as boiler stacks, chimney, exhaust and fume hoods on a regular basis. The objective for the monitoring is to determine the accurate degree of pollutants present in the air emitted from the stack. The standard of gas emission sampling is Malaysian Standard MS 1569:2003 while the parameters of testing are mainly based on the Clean Air Regulation 2014.