Значение и использование
Reference blocks fabricated in accordance with this practice will exhibit specific area-amplitude and distance-amplitude relationships only with an immersion test at 5 MHz using the search unit, test instrument and test parameters described in this practice. Comparison test at other frequencies or with uncalibrated instruments will not necessarily give the same relationships shown in this practice. See Reference (1) for area-amplitude limitations at other frequencies and transducer diameters. Also see Reference (2) for cautions regarding use of standard blocks for test standardizations.
1.1 This practice covers a procedure for fabrication and controlof metal alloy reference blocks used in ultrasonic examination thathave a flat-surface sound entry, are cylindrical in shape, andcontain flat-bottom holes (FBH) which may be used for checking theperformance of ultrasonic examination instrumentation and searchunits and for standardization and control of ultrasonic examinationof metal alloy products. The reference blocks described aresuitable for use with either the direct-contact method or immersionpulse-echo ultrasonic methods.
1.2 While this procedure is basically designed for thefabrication and control of carbon and alloy steel blocks to be usedin conjunction with the examination of these materials, thefabrication and control procedures may also be suitable for thepreparation of blocks for other types of materials such asnickel-base alloys, certain types of aluminum alloys, and so forth.Additional procedures and controls may be required when fabricatingreference blocks from other than carbon or alloy steel material.This practice shall in no way preclude the specification oraddition of any supplemented requirements as deemed necessary forthe specific application. This practice, however, must not beconfused with, nor does it supersede Practice E127, specificallygoverning the fabrication and evaluation of 7075-T6 aluminum alloyultrasonic standard reference blocks.
Note 1--Practice E127 and Guide E1158 also describe proceduresfor selecting material, fabricating blocks, and checking response.Unlike this practice, Practice E127 has requirements for evaluationrelative to a specified standard target.
1.3 The values stated in inch-pound units are to be regarded asthe standard.
1.4This standard does not purport to address all of thesafety problems, if any, associated with its use. It is theresponsibility of the user of this standard to establishappropriate safety and health practices and determine theapplicability of regulatory limitations prior to use.