Leak locating microphone, method and system for locating fluid leaks in pipes

• US 5,349,568 A
• Filed: 09/27/1993
• Issued: 09/20/1994
• Est. Priority Date: 09/27/1993
• Status: Expired due to Fees

• Current Assignee: University of Chicago
• Original Assignee: University of Chicago
• Inventors: Kupperman, David S., Spevak, Lev
• Primary Examiner(s): Pihulic, Daniel T.
• Application Number:
  US08/127,742
• Time in Patent Office: 358 Days
• Field of Search: 367/125, 367/167, 367/172, 367/163, 367/174, 367/159, 367/188, 367/155, 367/180, 73/40.5 A, 73/592
• US Class Current: 367/125
• CPC Class Codes: G01M 3/243 for pipes
• CPC Class Codes: G01S 3/8034 wherein the signals are derived simultaneously

Abstract

A leak detecting microphone inserted directly into fluid within a pipe includes a housing having a first end being inserted within the pipe and a second opposed end extending outside the pipe. A diaphragm is mounted within the first housing end and an acoustic transducer is coupled to the diaphragm for converting acoustical signals to electrical signals. A plurality of apertures are provided in the housing first end, the apertures located both above and below the diaphragm, whereby to equalize fluid pressure on either side of the diaphragm. A leak locating system and method are provided for locating fluid leaks within a pipe. A first microphone is installed within fluid in the pipe at a first selected location and sound is detected at the first location. A second microphone is installed within fluid in the pipe at a second selected location and sound is detected at the second location. A cross-correlation is identified between the detected sound at the first and second locations for identifying a leak location.

Claims

1. A leak detecting microphone for insertion directly into fluid within a pipe comprising:

a housing having a first end being inserted within the pipe and a second opposed end extending outside the pipe;

a diaphragm mounted within said first housing end;

an acoustic transducer coupled to said diaphragm for converting acoustical signals to electrical signals; and

a plurality of apertures provided in said housing first end, said apertures located both above and below said diaphragm, whereby to equalize fluid pressure on either side of the diaphragm.

2. A leak detecting microphone as recited in claim 1 wherein said housing is a generally cylindrical member formed of corrosion resistant material.

3. A leak detecting microphone as recited in claim 1 wherein said diaphragm is a member formed of corrosion resistant material.

4. A leak detecting microphone as recited in claim 1 wherein said diaphragm is formed of stainless steel.

5. A leak detecting microphone as recited in claim 1 wherein said acoustic transducer is a piezoelectric crystal.

6. A leak detecting microphone as recited in claim 1 wherein said acoustic transducer is a leadmetanioate crystal.

7. A leak detecting microphone as recited in claim 1 wherein said acoustic transducer is a piezoelectric transducer.

8. A leak locating system for locating fluid leaks within a pipe comprising:

first microphone means disposed within the pipe for detecting sound at a first selected location;

second microphone means disposed within the pipe for detecting a sound at a second selected location;

cross-correlator means responsive to said first microphone means and said second microphone means for identifying a leak location; and

wherein each of said first microphone means and said second microphone means include;

a housing having a first end being inserted within the pipe and a second opposed end extending outside the pipe;

a diaphragm mounted within said first housing end;

an acoustic transducer coupled to said diaphragm for converting acoustical signals to electrical signals; and

a plurality of apertures provides in said housing first end, said apertures located both above and below said diaphragm, whereby to equalize fluid pressure on either side of the diaphragm.