ASTM E127-98

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: E 127 – 98
Standard Practice for
Fabricating and Checking Aluminum Alloy Ultrasonic
Standard Reference Blocks
This standard is issued under the fixed designation E 127; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This specification has been approved for use by agencies of the Department of Defense.
1. Scope E 1158 Guide for Material Selection and Fabrication of
Reference Blocks for the Pulsed Longitudinal Wave Ultra-
1.1 This practice covers a procedure for fabricating alumi-
sonic Examination of Metal and Metal Alloy Production
num alloy ultrasonic standard reference blocks that can be used
Material
for checking performance of ultrasonic testing equipment and
E 1316 Terminology for Nondestructive Examinations
for standardization and control of ultrasonic tests of aluminum
E 1324 Guide for Measuring Some Electronic Characteris-
alloy products using pulsed longitudinal waves introduced into
tics of Ultrasonic Examination Instruments
test material either by the direct-contact method or by the
immersion method. A recommended procedure for checking
3. Terminology
blocks is described and calibration data for a number of
3.1 Definitions—For definitions of terms not specific to this
reference blocks are tabulated. Statements concerning proce-
practice, refer to Terminology E 1316.
dures are provided without a discussion of the technical
3.2 Definitions of Terms Specific to This Standard:
background for the preference. The necessary technical back-
2 3.2.1 angular error—the condition observed in ultrasonic
ground can be found in Refs. (1-14).
tests of reference blocks when the response from the hole
NOTE 1—Practice E 428 and Guide E 1158 also describe procedures for
bottom is not maximum while the search unit is positioned to
selecting material, fabricating blocks, and checking response. Unlike this
obtain either a maximum number of back reflections from a
practice, there is no requirement for evaluation relative to a specified
reference block or a maximum indication from its entry
standard target.
surface. Angular error results when the entry surface, hole
1.2 This standard does not purport to address all of the
bottom, and back surface are not parallel to each other.
safety concerns, if any, associated with its use. It is the
3.2.2 area-amplitude response curve—a curve showing the
responsibility of the user of this standard to establish appro-
relationship between different areas of reflecting targets located
priate safety and health practices and determine the applica-
at a constant distance in an ultrasonic transmitting medium and
bility of regulatory limitations prior to use.
their respective amplitudes of ultrasonic response.
3.2.3 back reflection—the indication, observed on the dis-
2. Referenced Documents
play screen of a test instrument, that represents the ultrasonic
2.1 ASTM Standards:
energy reflected from the back surface of a reference block.
E 317 Practice for Evaluating Performance Characteristics
3.2.4 back surface—the end of a reference block that is
of Ultrasonic Pulse-Echo Testing Systems Without the Use
opposite the entry surface.
of Electronic Measurement Instruments
3.2.5 entry surface—the end of a reference block through
E 428 Practice for Fabrication and Control of Steel Refer-
which ultrasonic energy must pass when reflections from the
ence Blocks Used in Ultrasonic Inspection
hole bottom are obtained.
3.2.6 hole bottom—the flat reflecting surface in a reference
block that is obtained by making the entire end of a drilled hole
This practice is under the jurisdiction of ASTM Committee E-7 on Nonde-
smooth and flat using best machining practices. The hole
structive Testing and is the direct responsibility of Subcommittee E07.06 on
bottom is parallel to the entry surface of the block.
Ultrasonic Method.
Current edition approved Dec. 10, 1998. Published February 1999. Originally
3.2.7 hole size—the diameter of the hole in a reference
published as E 127 – 58 T. Last previous edition E 127 – 95.
block that determines the area of the hole bottom.
The boldface numbers in parentheses refer to the list of references at the end of
3.2.8 metal distance—the distance in a reference block from
this practice.
Annual Book of ASTM Standards, Vol 03.03. its entry surface to the hole bottom.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E127–98
3.2.9 reference block—an aluminum block, containing as an pulse-echo ultrasonic test system. Establishment of distance-
artificial discontinuity a flat-bottom drilled hole of known size. amplitude and area-amplitude characteristics is necessary for
3.2.10 ultrasonic response—the height of the indication, each application.
observed on a display screen of a test instrument, that repre-
6. Description of Various Recommended Sets
sents the amount of ultrasonic energy initially reflected from
the hole bottom in a reference block. Units usually used in
6.1 In ultrasonic testing of aluminum alloy products, a
measuring height of indication are inches, trace-to-peak, or
standard reference usually is necessary to establish a specified
percent of upper linearity limit. test sensitivity. A standard ultrasonic reference also is required
frequently to determine the effect of variations in metal
4. Summary of Practice distance upon the ultrasonic response from detected disconti-
nuities. Test sensitivity standardizations and corrections for
4.1 Aluminum alloy stock is ultrasonically evaluated to
metal distance are most reliable when made under the same
ensure freedom from significant discontinuities and is then
conditions employed for the actual tests. For these purposes,
precisely fabricated into cylindrical blocks of prescribed
aluminum alloy reference blocks containing various combina-
lengths. A single, flat-bottom hole of specific diameter is drilled
tions of hole size and metal distance are necessary.
to a constant depth into the end of each block at its center, and
6.2 The following combinations or sets of blocks are rec-
the blocks are grouped into sets according to hole size and
ommended:
block length, or metal distance.
6.2.1 Basic Set——The basic set consisting of ten reference
4.2 Each block is checked ultrasonically using a calibrated
blocks is listed in Table 1. Area-amplitude relations are
ultrasonic test system at a prescribed test frequency. Dis-
obtained by intercomparison of blocks containing the 3-in.
tanceamplitude and area-amplitude characteristics are estab-
(76.2-mm) metal distance and 3/64-in., 5/64-in., and 8/64- in.
lished for sets of fabricated blocks using specific reflectors to
(Note 3) diameter holes, respectively. Distance-amplitude re-
provide a standard response. Curves are plotted to establish the
lations are obtained by intercomparison of the blocks of
interrelationship between the various blocks in the sets.
various lengths which contain 5/64-in. diameter holes.
4.3 To permit the use of instrumentation similar to that
originally used in developing this practice, or types more
NOTE 3—Direct conversion from inches to millimetres (1 in. = 25.4
recently manufactured, two alternative test system calibration
mm) gives hole size dimensions for which there are no standard metric
drills; however, Table 2 gives the nearest standard metric drill size.
procedures are described. The first method (ball-to-block)
which utilizes steel balls as reference standards, is covered in
6.2.2 Area-Amplitude Set—The area-amplitude set consist-
11.8.2. The second method (block-to-block), which requires as
ing of eight ultrasonic standard reference blocks is listed in
reference standards, blocks which have been calibrated by the
Table 3. Area-amplitude relationships at one metal distance are
National Institute of Standards and Technology (NIST), is
obtained by intercomparison of blocks in this set.
described in Annex A1.
6.2.3 Distance-Amplitude Set—A distance-amplitude set
may include any convenient number of the reference blocks
5. Significance and Use
shown in Table 4 and does not necessarily include all blocks
5.1 Reference blocks fabricated to this practice will exhibit
listed. A recommended distance-amplitude set contains at least
specific area-amplitude and distance-amplitude relationships 12 blocks, and each set contains only one of the three hole sizes
only with an immersion test at 5 MHz using the search unit,
shown in Table 4. Blocks comprising the 19 block distance-
test instrument, and test parameters described in this practice. amplitude sets, which are customarily supplied commercially,
Comparison tests at other frequencies or with uncalibrated test
are indicated in Table 4. Increments of metal distance in each
systems will not necessarily give the same relationships shown of the three groups of blocks in the recommended set should be
in this practice.
identical. Distance-amplitude relationships are obtained by
intercomparison of all blocks containing the same size hole.
NOTE 2—The 1964 and prior issues of this practice required a test
frequency of 15 MHz. Blocks conforming to earlier issues of this practice
may not produce ultrasonic responses that conform to this issue. See
TABLE 1 Dimensions and Identification of Reference Blocks in
Section 13 regarding provision for recertification or correction curves and
the Basic Set (see Fig. 1)
tables.
Hole Metal Overall
Block
Diameter Distance Length
5.2 Although the primary ultrasonic evaluation of blocks is
Identi-
(A) (B) (C)
performed at a specified frequency, the blocks may be used to
fication
⁄64 ths
Number
standardize ultrasonic tests at any frequency and with any
in. mm in. mm
in.
3-0300 3 3.000 76.2 3.750 95.2
5-0012 5 0.125 3.2 0.875 22.2
5-0025 5 0.250 6.4 1.000 25.4
Measurement services to determine the ultrasonic response of reference blocks
5-0050 5 0.500 12.7 1.250 31.8
intended to meet the requirements of this practice are available from the National
5-0075 5 0.750 19.0 1.500 38.1
Institute of Standards and Technology (formerly NBS), Office of Measurement
5-0150 5 1.500 38.1 2.250 57.2
Services, Gaithersburg, MD 20899. Unless otherwise requested, the calibration
5-0300 5 3.000 76.2 3.750 95.2
procedure used by NIST is that based on Publication NIST IR 5430. This has small
5-0600 5 6.000 152.4 6.750 171.4
but significant differences from that in this practice; however the NIST data base
8-0300 8 3.000 76.2 3.750 95.2
indicates that the NIST procedure is in consonance with the requirements of the 8-0600 8 6.000 152.4 6.750 171.4
practice.
E127–98
TABLE 2 Diameter of Flat-Bottom Holes in Inch-Pound Units and TABLE 4 Dimensions and Identification of Reference Blocks in
the Nearest Metric Drill Hole Diameter Distance-Amplitude Sets (see Fig. 1 and refer to 6.2.3)
Block Identifica-
Metal Distance (B) Overall Length (C)
NOTE 1—Ratio of the area of the nearest metric drill size to the area of
tion Number, 3-,
the inch-pound drill size is 1.016 throughout.
A
in. mm in. mm
5-, and 8-
Hole Diameter in Inch- Nearest Metric Drill
B
−0006 0.0625 1.6 0.812 20.6
Pound Units, in. Size, mm
B
−0012 0.125 3.2 0.875 22.2
B
−0025 0.250 6.4 1.000 25.4
1/64 0.40
B
2/64 0.80 −0038 0.375 9.5 1.125 28.6
B
3/64 1.20 −0050 0.500 12.7 1.250 31.8
B
4/64 1.60 −0062 0.625 15.9 1.375 34.9
B
5/64 2.00 −0075 0.750 19.1 1.500 38.1
B
−0088 0.875 22.2 1.625 41.3
6/64 2.40
B
7/64 2.80 −0100 1.000 25.4 1.750 44.5
B
−0125 1.250 31.8 2.000 50.8
8/64 3.20
−0150 1.500 38.1 2.250 57.2
B
−0175 1.750 44.5 2.500 63.5
−0200 2.000 50.8 2.750 69.9
B
TABLE 3 Dimensions and Identification of Reference Blocks in
−0225 2.250 57.2 3.000 76.2
the Area-Amplitude Set (see Fig. 1)
−0250 2.500 63.5 3.250 82.6
B
−0275 2.750 69.9 3.500 88.9
Hole Metal Overall
−0300 3.000 76.2 3.750 95.3
Block
Diameter Distance Length
B
−0325 3.250 82.6 4.000 101.6
Identi-
(A) (B) (C)
−0350 3.500 88.9 4.250 108.0
fication
1 B
⁄64 ths
−0375 3.750 95.3 4.500 114.3
Number
in. mm in. mm
in.
−0400 4.000 101.6 4.750 120.7
B
−0425 4.250 108.0 5.000 127.0
1-0300 1 3.000 76.2 3.750 95.3
−0450 4.500 114.3 5.250 133.4
2-0300 2 3.000 76.2 3.750 95.3
B
−0475 4.750 120.7 5.500 139.7
3-0300 3 3.000 76.2 3.750 95.3
−0500 5.000 127.0 5.750 146.1
4-0300 4 3.000 76.2 3.750 95.3
B
−0525 5.250 133.4 6.000 152.4
5-0300 5 3.000 76.2 3.750 95.3
−0550 5.500 139.7 6.250 158.8
6-0300 6 3.000 76.2 3.750 95.3
B
−0575 5.750 146.1 6.500 165.1
7-0300 7 3.000 76.2 3.750 95.3
−0600 6.000 152.4 6.750 171.5
8-0300 8 3.000 76.2 3.750 95.3
−0625 6.250 158.8 7.000 177.8
−0650 6.500 165.1 7.250 184.2
A
3 5 8
Hole diameters (A) ⁄64 , ⁄64 , and ⁄64 in.
B
Area-amplitude relationships are obtained by intercomparison Blocks customarily included in commercial 19 block distance-amplitude sets.
of any three or more blocks containing the same metal
6 5°C) for a period of 1 h 6 5 min, quenching immediately by immersing
distance.
vertically into water at room temperature, aging in air at room temperature
6.3 If the blocks are to be used for immersion testing, they
for 4 days 61 h, followed by air aging at 250 6 10°F (120 6 5°C) for 24
should be suitably anodized or otherwise protected to enhance
6 1 h. To minimize distortion during vertical quenching, it is recom-
resistance to corrosion. Blocks with coated surfaces may be
mended that stock be re-heat treated in lengths of approximately 20 in.
used with search units requiring external ground provided
(508 mm).
suitable arrangements are made for adequate electrical contact.
7.2 The stock shall not be less than 2.00 in. (50.8 mm) nor
Uncoated blocks shall be designated as Type 1; coated blocks
more than 2.25 in. (57.2 mm) in diameter and up to 7.25 in.
shall be designated as Type 2. The ultrasonic characteristics of
(184 mm) in length for the blocks covered by this practice.
both types shall be checked by the immersion method as
8. Quality of Material
prescribed in Section 11. However, care must be exercised to
dry the Type 1 blocks subsequent to immersion in water. The
8.1 The quality of material to be used for reference blocks
protective coating used on the Type 2 blocks shall not change
should be checked by the procedure outlined in 8.2 to 8.9
their ultrasonic characteristics.
inclusive. Only material passing the requirements given in 8.9
6.4 A number of important variables that affect the response
should be used for blocks.
from reference blocks can be controlled during fabrication by
8.2 Evaluation Procedure—The general evaluation proce-
accurate machining practices. The roughness o
...