Method and apparatus for acoustically monitoring the flow of suspended solid particulate matter

An acoustic apparatus for monitoring the flow of particulate matter in a flowable medium, the flowable medium being characterized in having an acoustic noise distribution over a broad frequency spectrum, comprising:

• a transducer coupled to said flowable medium to sense sound waves therein and to generate an electrical signal representative of the flow of the particulate matter in said flowable medium;
• a filter circuit, coupled to said transducer, and comprising a low frequency band pass filter to generate a first output signal, an intermediate frequency band pass filter to generate a second output signal, and a high frequency band pass filter to generate a third output signal;
• a first ratio circuit coupled to said low frequency band pass filter and said intermediate frequency band pass filter to generate a first ratio signal, said first ratio signal being a function of said first output signal divided by said second output signal and being representative of the relative concentration of the particulate matter in the flowable medium;
• and
• a second ratio circuit coupled to said low frequency band pass filter and said high frequency band pass filter to generate a second ratio signal, said second ratio signal being a function of said first output signal divided by said third output signal and being representative of the flow/no-flow condition of the particulate matter in the flowable medium.