The principle of measuring pulverized coal concentration by using momentum method for exhaust gas transfering and directly injecting type pulverized coal boilers has been expounded from theoritical aspect. Based on momentum law

and regarding airsolid twophase flow as an entity

the internal complex movement in fluid involved in measuring pulverized coal concentration is converted into studying the interaction between fluid and outside medium. Field test shows that the accuracy of measuring pulverized coal concentration by using the said method can meet the requirements of engineering

reflecting rapidly and sensitively the variation of pulverized coal concentration

having certain feasibility and practicality

opening up a new way in engineering practice for measuring pulverized coal concentration for utility boilers.