Digital ultrasonic monitoring system and method

• US 6,247,353 B1
• Filed: 12/10/1999
• Issued: 06/19/2001
• Est. Priority Date: 05/04/1998
• Status: Active Grant

• Current Assignee: Computational Systems Incorporated (Emerson Electric Company)
• Original Assignee: CSI Technology Incorporated (Emerson Electric Company)
• Inventors: Carpenter, Terry G., Vanvoorhis, James B., Puterbaugh, Kenneth C., Robinson, James C., Johnson, William S., Piety, Kenneth R., Battenberg, Rexford A.
• Primary Examiner(s): CHAPMAN JR, JOHN E
• Application Number:
  US09/458,293
• Time in Patent Office: 557 Days
• Field of Search: 73/405.A, 735/84, 735/92, 736/32, 736/58, 736/60, 73/18.2, 736/46, 702/51, 702/54
• US Class Current: 73/40.50A
• CPC Class Codes: G01H 1/003 of rotating machines G01H1/10 takes precedence
• CPC Class Codes: G01H 3/00 Measuring characteristics of vibrations by using a detector in a fluid G01H7/00, G01H9/00, G01H11/00 take precedence
• CPC Class Codes: G01M 3/24 using infrasonic, sonic, or ultrasonic vibrations
• CPC Class Codes: G01M 3/243 for pipes
• CPC Class Codes: G01N 29/14 using acoustic emission techniques echo of particles G01N29/046; measuring mechanical vibrations or acoustic waves in solids in general G01H1/00
• CPC Class Codes: G01N 29/36 Detecting the response signal , e.g. electronic circuits specially adapted therefor
• CPC Class Codes: G01N 29/44 Processing the detected response signal , e.g. electronic circuits specially adapted therefor digital signal processing per se G06F17/00
• CPC Class Codes: G01N 29/4454 Signal recognition, e.g. specific values or portions, signal events, signatures

Abstract

A portable digital ultrasonic monitoring system and method for use by an operator in detecting the ultrasonic waves and temperature variations produced by sources such as leaks in pipes, arcing, electrical corona and machinery defects is provided. The digital ultrasonic monitoring system includes a microprocessor based system in a hand held elongate housing that digitally analyzes and stores information received from its sensors. The digital ultrasonic monitoring system provides a referenced decibel output reading of the signal strength of the received ultrasonic signals. In addition, a heterodyned type audio signal that is related to the sensed ultrasonic signals is provided to the operator through a pair of headphones. The portable device has user input keys that allow the operator to select from a variety of different operating modes. A display displays a variety of different readings depending upon the operating mode of the device.

Claims

1. A portable digital ultrasonic sound detection and analysis device for measuring and detecting ultrasonic sounds, the digital ultrasonic device comprising:

an elongate housing for enclosing the digital ultrasonic device wherein the elongate housing further comprises a grip that is designed to provide a handle that allows a user to carry and point the digital ultrasonic device and a trigger which is used to control the functioning of the digital ultrasonic device;

a set of sensors including at least a temperature sensor and an ultrasonic sensor;

a sensor socket located in the elongate housing of the ultrasonic device that is designed to interchangeably receive a sensor from the set of sensors wherein the sensor socket comprises;

a cavity having walls and a bottom portion for receiving the sensor from the set of sensors;

a set of pins located in the bottom portion of the sensor socket for providing electrical contacts between a plurality of electrical contacts on the sensor installed in the sensor socket and the digital ultrasonic device; and

at least one groove located in the walls of the cavity wherein the at least one groove has an open receiving portion that begins at the rim of the cavity and extends a distance down the cavity walls to an ending position and a leg portion that extends substantially perpendicularly from the ending position of the open receiving portion;

at least one protrusion fixedly attached to the sides of each of the sensors in the set of sensors wherein the protrusion is shaped and positioned to be received in the at least one groove in a manner that removably secures the sensor in the sensor socket;

installation guide means which prevent a sensor from the set of sensors from being improperly installed in the sensor socket;

an identification circuit located on each sensor in the set of sensors that contains identification and configuration information concerning the sensor;

a power supply located in the grip of the elongate housing that provides a power supply voltage and a ground voltage to the digital ultrasonic device;

a received signal strength indicator for receiving ultrasonic electrical signals from a sensor installed in the sensor socket that correspond to ultrasonic sounds detected by the sensor and producing a signal indicative of the strength of the ultrasonic sounds;

a variable frequency sine wave oscillator for producing local oscillator frequency signals;

a mixer for receiving the ultrasonic electrical signals from a sensor installed in sensor socket and the local oscillator frequency signals from the variable frequency sine wave oscillator and heterodyning the ultrasonic electrical signals to produce audible frequency range signals that correspond to the ultrasonic electrical signals but are in the audible frequency range of a human being;

a pair of headphones that receive the audible frequency range signals and broadcast the audible frequency range signals so that they can be heard by a user of the digital ultrasonic device;

a temperature sense circuit for sending a constant current to an installed temperature sensor and creating a temperature signal corresponding to the temperature sensed by the installed sensor;

a set of input keys located on the elongate housing that allow the user to control the functioning of the digital ultrasonic device;

a display for displaying properties of the sensed ultrasonic electrical and temperature signals;

a microprocessor for controlling the functioning of the digital ultrasonic sound detection and analysis device;

a memory for selectably storing information concerning the ultrasonic electrical signals and configuration parameters for the set of sensors;

a communications port located on the elongate housing that allows the microprocessor in the digital ultrasonic device to communicate with a host computer;

a signal output for providing the signal indicative of the strength of the ultrasonic electrical signals received from the received signal strength indicator to an external machine analyzer for time domain and frequency analysis; and

an ultrasonic tone generator for introducing an ultrasonic tone into a vessel, pipe or container that is being checked for holes or leaks.

2. A portable passive device for detecting and analyzing ultrasonic sound waves or vibrations, said portable device comprising:

an ultrasonic sensor for sensing ultrasonic sound or vibrations wherein said ultrasonic sensor produces ultrasonic electrical signals that correspond to the sensed ultrasonic sound or vibrations;

a sensor socket wherein said ultrasonic sensor may be interchangeably received in said sensor socket such that said ultrasonic sensor can be removed from said sensor socket and replaced by a second ultrasonic sensor wherein said second ultrasonic sensor senses different ultrasonic properties than said removed ultrasonic sensor;

digital processing means for receiving and digitally analyzing the ultrasonic electrical signals to produce a peak hold value of said ultrasonic electrical signals;

a memory for digitally storing results of said digital analysis; and

output means for communicating the results of said digital analysis to a central computer.

3. The device of claim 2 wherein said ultrasonic sensor senses airborne ultrasonic sound and said second ultrasonic sensor senses ultrasonic vibrations by being placed into contact with an object producing ultrasonic vibrations.

4. The device of claim 3 wherein said output means further comprise an infrared communications port for sending and receiving data.

5. The device of claim 4 wherein the output means further comprise a display for visually displaying results of the digital analysis of the ultrasonic electrical signals and information concerning the functioning and configuration of the device.

6. The device of claim 5 further comprising a split signal path for providing said ultrasonic electrical signals to a received signal strength indicator circuit that produces a signal representative of the strength of the ultrasonic electrical signals and a frequency conversion means that produces audible frequency range signals that correspond to the ultrasonic electrical signals but are in the audible frequency range of a human being.

7. The device of claim 6 wherein the frequency conversion means is a heterodyne circuit.

8. The device of claim 7 wherein the digital processing means can be reprogrammed in the field to incorporate firmware updates.

9. The device of claim 8 wherein the device is powered by a rechargeable power supply.

10. The apparatus of claim 7 further comprising an ultrasonic sound wave generator that can be placed inside of an object so that ultrasonic sound waves will escape from any openings in the walls of the object.

11. The apparatus of claim 6 further comprising alarm means for indicating when the sensed ultrasonic electrical signals exceed a user selected threshold value.

12. The apparatus of claim 4 wherein either said first or said second ultrasonic sensor has an integral temperature sensor.

13. The apparatus of claim 4 wherein said received ultrasonic sensor is electrically connected to both a received signal strength indicator circuit and a heterodyning audio circuit by a split signal path when received in said sensor socket.

14. The device of claim 2 further comprising means for providing a referenced decibel value of the ultrasonic sound waves or ultrasonic vibrations to the output means.

15. The device of claim 14 further comprising an envelope detector for producing a demodulation envelope wherein a DC voltage value of an instantaneous point on said demodulation envelope corresponds to said referenced decibel value.

16. A passive apparatus for detecting and analyzing ultrasonic sound or vibrations wherein said apparatus is adapted to be portable, said apparatus comprising:

a first ultrasonic sensor for sensing ambient ultrasonic sound or vibrations and producing ultrasonic electrical signals that correspond to the ultrasonic sound or vibrations;

a second ultrasonic sensor for sensing ambient ultrasonic sound or vibrations and producing ultrasonic electrical signals that correspond to the ultrasonic sound or vibrations wherein said second ultrasonic sensor has sensing properties that are different from said first ultrasonic sensor; and

a sensor socket for removably receiving either said first ultrasonic sensor or said second ultrasonic sensor and coupling said received ultrasonic sensor to a microprocessor wherein said microprocessor digitally analyzes said ultrasonic electrical signals by performing time domain analysis on said ultrasonic electrical signals.

17. An apparatus for detecting and analyzing ultrasonic sound or vibration, said apparatus comprising:

a pistol shaped housing for containing the apparatus wherein said pistol shaped housing is adapted to be portably held in the hand of a user;

a trigger mounted on said pistol shaped housing for controlling said apparatus;

a sensor socket on said pistol shaped housing for interchangeably receiving a sensing module from a set of sensing modules wherein said received sensing module senses ultrasonic sound or vibrations and produces electrical signals corresponding to said sensed ultrasonic sound or vibrations;

a microprocessor for receiving and analyzing said electrical signals and producing data including a peak hold value and a referenced decibel value;

an audio output circuit for producing a heterodyned audio output signal based on said electrical signals;

a memory for storing selected portions of said produced data;

an RS 232 data output port for outputting selected portions of said produced data such that said data can be trended;

a display for displaying said referenced decibel output; and

a headphone output on said pistol shaped housing for receiving said heterodyned audio output signal and providing an audio output to a pair of headphones.

18. A portable passive device for detecting and analyzing ultrasonic sound waves or vibrations, said portable device comprising:

a sensor socket for interchangeably receiving an ultrasonic sensor from a set of ultrasonic sensors wherein said set of sensors includes a first ultrasonic sensor that senses airborne ultrasonic sound and a second ultrasonic sensor that senses ultrasonic vibrations by being placed into contact with an object producing ultrasonic vibrations;

digital processing means for receiving and digitally analyzing the ultrasonic electrical signals to produce a peak factor value, a peak hold value, an average signal level value or an instantaneous peak signal value of said ultrasonic electrical signals;

a memory for digitally storing results of said digital analysis; and

output means for communicating the results of said digital analysis to a central computer.