US4039767A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic emission transducer calibration
Assignee: Westinghouse Electric Corp
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Filing: 1975-07-14
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Granted: 1977-08-02
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Expires: 1995-07-14
Abstract
Abstract A method of calibrating acoustic emission transducers. The sensitivity of a standard transducer is first determined utilizing a reciprocity calibration technique, and the standard transducer and the acoustic emission transducer are then connected to a bounded acoustic medium. Random acoustic white noise is transmitted into the acoustic medium thereby establishing a multi-mode reverberant sound field, and the output responses from the standard transducer and the acoustic emission transducer to the reverberant sound field are obtained and compared to determine the sensitivity of the acoustic emission transducer.
Inventors
- 👤 Walter C. Leschek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:11
CPC Classifications
G; G01; G01V; G01V13/00; G01D; G01D18/00; G01N; G01N29/00; G01N29/22; G01N29/30; G01N2291/00; G01N2291/26; G01N2291/269; G01N2291/2695
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
190 words
A method of calibrating an acoustic emission transducer to operate within a predetermined range of frequencies in a given application comprising: determining the absolute receiving sensitivity of a standard transducer at selected frequencies within said range of frequencies; placing said standard transducer and said acoustic emission transducer in acoustical communication with a surface of a bounded acoustic medium presenting a substantially equivalent acoustic loading to the medium on which the acoustic emission transducer is to be used in its given application, said bounded acoustic medium comprising a block, each dimension of said block being at least approximately equal to a thickness of said acoustic medium on which said acoustic emission transducer is to be used in its given application; transmitting acoustic random white noise into said acoustic medium to establish a reverberant, diffuse sound field; obtaining the output response of said primary transducer and said acoustic emission transducer to the reverberant, diffuse sound field at selected frequencies within said range of frequencies; and comparing said acoustic emission transducer output response with said standard transducer output response at said selected frequencies to determine the receiving sensitivity of said acoustic emission transducer.
Claim 2
Independent Claim
190 words
A method of calibrating an acoustic emission transducer to operate within a predetermined range of frequencies in a given application comprising: determining the absolute receiving sensitivity of a standard transducer at selected frequencies within said range of frequencies; placing said standard transducer and said acoustic emission transducer in acoustical communication with a surface of a bounded acoustic medium presenting a substantially equivalent acoustic loading to the medium on which the acoustic emission transducer is to be used in its given application, said bounded acoustic medium comprising a block, each dimension of said block being at least approximately equal to a thickness of said acoustic medium on which said acoustic emission transducer is to be used in its given application; transmitting acoustic random white noise into said acoustic medium to establish a reverberant, diffuse sound field; obtaining the output response of said primary transducer and said acoustic emission transducer to the reverberant, diffuse sound field at selected frequencies within said range of frequencies; and comparing said acoustic emission transducer output response with said standard transducer output response at said selected frequencies to determine the receiving sensitivity of said acoustic emission transducer.
Claim 3
Dependent Claim
45 words
A method according to claim 1 wherein comparing said acoustic emission transducer output response with said standard transducer output response comprises: equating said standard transducer output response with said standard transducer sensitivity; and comparing said acoustic emission transducer output response with said standard transducer sensitivity.
Claim 4
Dependent Claim
20 words
The method according to claim 1 including utilizing a reciprocity calibration technique for determining the sensitivity of said standard transducer.
Claim 5
Dependent Claim
12 words
The method according to claim 1 including constructing said block of steel.
Claim 6
Dependent Claim
38 words
The method according to claim 1 including filtering said standard transducer output response and said acoustic emission transducer output response through a spectrum analyzer to obtain said responses within a predetermined bandwidth of frequencies at said selected frequencies.
Claim 7
Dependent Claim
23 words
The method according to claim 5 including transmitting said standard transducer output response and said acoustic emission transducer output response to a recorder.
Claim 8
Independent Claim
178 words
A method of calibrating an acoustic emission transducer to operate within a predetermined range of frequencies in a given application comprising: determining the absolute receiving sensitivity of a standard transducer at selected frequencies within said range of frequencies; placing said standard transducer and said acoustic emission transducer in acoustical communication with a surface of a bounded acoustic medium presenting a substantially equivalent acoustic loading to the medium on which the acoustic emission transducer is to be used in its given application, said bounded acoustic medium comprising a rectangular block dimensioned according to the proportion one to the cube root of two to the cube root of four; transmitting acoustic random white noise into said acoustic medium to establish a reverberant, diffuse sound field; obtaining the output response of said primary transducer and said acoustic emission transducer to the reverberant, diffuse sound field at selected frequencies within said range of frequencies; and comparing said acoustic emission transducer output response with said standard transducer output response at said selected frequencies to determine the receiving sensitivity of said acoustic emission transducer.
Claim 9
Independent Claim
178 words
A method of calibrating an acoustic emission transducer to operate within a predetermined range of frequencies in a given application comprising: determining the absolute receiving sensitivity of a standard transducer at selected frequencies within said range of frequencies; placing said standard transducer and said acoustic emission transducer in acoustical communication with a surface of a bounded acoustic medium presenting a substantially equivalent acoustic loading to the medium on which the acoustic emission transducer is to be used in its given application, said bounded acoustic medium comprising a rectangular block dimensioned according to the proportion one to the cube root of two to the cube root of four; transmitting acoustic random white noise into said acoustic medium to establish a reverberant, diffuse sound field; obtaining the output response of said primary transducer and said acoustic emission transducer to the reverberant, diffuse sound field at selected frequencies within said range of frequencies; and comparing said acoustic emission transducer output response with said standard transducer output response at said selected frequencies to determine the receiving sensitivity of said acoustic emission transducer.
References Cited (Backward Citations)
DE1066622B
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-01 | 1981-01-31 | 1981-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-01 | 1985-01-31 | 1985-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-01 | 1989-01-31 | 1989-08-02 | $7700.00 | Window Closed / Lapsed |