The working principle and measuring method of particle size determination for liquiddroplets carried in gas flow by using impact diaphragm method have been presented

and the operation steps for applying magnesium oxide film or vaseline film on the carrier glass being given. The said method has low cost

being easy to operate

and suitable for measuring liquiddroplets or fogdroplets in outlet or inlet of mistremover in flue gas cooling facility and wet desulphurization system of boilers.