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J. Zhang et al.
not have the test conditions and capabilities. Only a few institutions in different countries have the ability of the AE sensor calibration. And, the primary calibrated sensor
is a necessary condition for secondary calibration. In China, the National Institute
of Metrology uses a laser vibrometer instead of the standard transducer to perform
primary calibration of the AE sensors. In western countries, since the National Institute of Standards and Technology (NIST, USA), the only neutral supplier of calibration services stopped offering primary calibration service to external customers,
no such primary calibrated sensor can be provided to other organizations for the
secondary calibration services of AE sensors. The AE sensor manufactures, such as
PAC and Vallen, use face-to-face method to get the sensor’s frequency response. It
was also suggested as a secondly calibration method [21]. Based on the research of
this method, Mr. Hartmut Vallen proposed an ISO standard draft and the project has
been established in ISO/TC135/SC9. The standard ISO/WD 24543 “Non-destructive
testing—Acoustic emission testing—Verification of the receiving sensitivity spectra
of piezoelectric acoustic emission sensors” now is in the working draft stage [22].
4.5 Conclusions
After more than 50 years of development of AE equipment, the performance of the
AE instruments and sensors has gradually improved. More and more types of AE
instruments and sensors have been developed, and the corresponding performance
testing methods and standards have also been continuously improved. A comprehensive understanding of the performance testing of AE instruments and sensors was
obtained by comparing and analyzing the performance testing status and standards,
and the following conclusions were obtained.
(1) For the performance test of AE instruments, the United States developed standards is the earliest. The standards developed in Europe are systematized, and the
number of standards developed in China is the largest. Most of the test devices
used by each standard are the same, and there are certain commonalities and
differences in the test parameters. In addition to the bandwidth and some other
parameters that are of common concern, there are also some specific parameters
that each standard focuses on.
(2) For the performance test of AE sensors, the United States, ISO and China all use
the standards of primary calibration and secondary calibration as the test basis.
In view of the inconvenience of the test devices and the lack of test suppliers,
ISO is developing a new standard and hoping to provide an alternative to AE
sensor calibration.
Acknowledgements This work is financially supported by the Science and Technology Plan Project
of State Administration for Market Regulation (No. 2020MK175), also the Internal Research Project
of China Special Equipment Inspection and Research Institute (No. 2020QingNian02).
J. Zhang et al.
not have the test conditions and capabilities. Only a few institutions in different countries have the ability of the AE sensor calibration. And, the primary calibrated sensor
is a necessary condition for secondary calibration. In China, the National Institute
of Metrology uses a laser vibrometer instead of the standard transducer to perform
primary calibration of the AE sensors. In western countries, since the National Institute of Standards and Technology (NIST, USA), the only neutral supplier of calibration services stopped offering primary calibration service to external customers,
no such primary calibrated sensor can be provided to other organizations for the
secondary calibration services of AE sensors. The AE sensor manufactures, such as
PAC and Vallen, use face-to-face method to get the sensor’s frequency response. It
was also suggested as a secondly calibration method [21]. Based on the research of
this method, Mr. Hartmut Vallen proposed an ISO standard draft and the project has
been established in ISO/TC135/SC9. The standard ISO/WD 24543 “Non-destructive
testing—Acoustic emission testing—Verification of the receiving sensitivity spectra
of piezoelectric acoustic emission sensors” now is in the working draft stage [22].
4.5 Conclusions
After more than 50 years of development of AE equipment, the performance of the
AE instruments and sensors has gradually improved. More and more types of AE
instruments and sensors have been developed, and the corresponding performance
testing methods and standards have also been continuously improved. A comprehensive understanding of the performance testing of AE instruments and sensors was
obtained by comparing and analyzing the performance testing status and standards,
and the following conclusions were obtained.
(1) For the performance test of AE instruments, the United States developed standards is the earliest. The standards developed in Europe are systematized, and the
number of standards developed in China is the largest. Most of the test devices
used by each standard are the same, and there are certain commonalities and
differences in the test parameters. In addition to the bandwidth and some other
parameters that are of common concern, there are also some specific parameters
that each standard focuses on.
(2) For the performance test of AE sensors, the United States, ISO and China all use
the standards of primary calibration and secondary calibration as the test basis.
In view of the inconvenience of the test devices and the lack of test suppliers,
ISO is developing a new standard and hoping to provide an alternative to AE
sensor calibration.
Acknowledgements This work is financially supported by the Science and Technology Plan Project
of State Administration for Market Regulation (No. 2020MK175), also the Internal Research Project
of China Special Equipment Inspection and Research Institute (No. 2020QingNian02).