The Napp-Baldwin model 31, exhaust sampling system is a modular device which employs compatible elements to allow its adaptation to different methods, designed for the monitoring of industrial chimneys, in order to ensure their correct function and the evaluation of their emissions.

Designed and developed by engineers with ample experience in chimney sampling, model 31 is the most flexible, robust and easy to operate (at present, they can be found operating correctly in systems which were supplied 20 years ago.

Its modular design enables the configuration of the equipment for the sampling by all EPA methods (Methods 1-17). Through the use of optional compatible elements, all sampling needs can be covered to meet EPA standard Methods.