GB/T 18694-2002
Non-destructivetesting--Ultrasonic inspection--Characterization of search unit and sound field (English Version)

Standard No.

GB/T 18694-2002

Language

Chinese, Available in English version

Release Date

2002

Published By

General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China

Latest

GB/T 18694-2002

Scope

This standard specifies certain properties of ultrasonic probes and test methods for the sound field of the probe. The purpose of this standard is to establish a unified test method to form an evaluation basis to evaluate the measurement results in different laboratories and in different periods. This standard does not specify the acceptance criteria for the probe, but it lays the technical foundation for the parties adopting this standard to specify the acceptance criteria. This standard applies to straight and angled probes with a nominal frequency of 0.5 to 15 MHz, but does not include surface wave probes. This standard gives the technical parameters of the sound field of the probe and its measurement method in liquid. This standard does not address the measurement of sound fields in contact testing. This standard gives the measurement procedures for evaluating the performance of ultrasonic probes and the test methods for the technical parameters of the sound field of the probes used in the field and laboratory using electric pulse excitation. The performance parameters discussed in this standard include the following: high and low end frequencies, center frequency, wavelength, bandwidth, time and frequency domain responses, near-field length, half-diffusion angle and echo of probes of various shapes in a free sound field Amplitude measurement, beam cross section sound pressure distribution, impedance and relative sensitivity etc. The expressions for the specified performance of flat probes and focused probes are given. To give baseline information for the probe and to check for possible performance degradation, the electrical performance of the probe was also measured independent of the ultrasound instrument. Electrical impedance and sensitivity are measured at the specified frequency of each probe under test. Electrical impedance refers to the input complex impedance of the probe, while probe sensitivity is a measure of the electroacoustic conversion efficiency of the probe. The test procedures for these two items are described in 4.6 and 4.7, respectively.

GB/T 18694-2002 history

• 2002 GB/T 18694-2002 Non-destructivetesting--Ultrasonic inspection--Characterization of search unit and sound field