Abstract: The invention provides a method of, and apparatus for detecting and analyzing moving particles using an impact responsive transducer which generates a detection signal having an amplitude related to force of particle impact. The transducer output signal is monitored and when it exceeds a given threshold, any local maximum values are noted. Those values are compared to determine which has the overall maximum amplitude. A final signal is then generated in order to provide a representation of the maximum value, and hence the momentum and time occurrence of a particle impact.