AWS Procedure - Rev 2.pdf
Transcript of AWS Procedure - Rev 2.pdf
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Forward
While it is recognized that phased array technology is becoming more widespread and
popular within various industries, it has not yet been specifically addressed by the
AWS. The following document was written to satisfy customer requests. Its purpose is
to serve as a guideline to align the Phasor XS with the current methodology prescribed
in Clause 6, Part F, of the AWS D1.1, 2008 Code.
This is achievable due to the well-established fact that an array transducer with the
same physical properties of size, shape, and frequency, as a conventional monolithic
transducer, will have identical acoustic properties.
This document has been produced in typical procedure format, for the sake of
familiarity. As such, it is intended as a guideline only.
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Table of contents
SECTION PAGE
1. Scope 3
2. References 3
3. Personnel 4
4. Equipment 4
5. Calibration 6
6. Examination 13
7. Indication evaluation and reporting 18
Annex A: dB Accuracy Procedure 23
Annex B: Horizontal Linearity Procedure 29
Annex C: Search Unit Check 33
Annex D: Drawings 37
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1. Scope
1.1.This procedure describes the use of the Phasor XS utilizing the sectorial and
A-scan views. For the detection and interpretation of discontinuities in groovetype welds and the associated heat affected zones (HAZ). Applicable part
thickness range is from 5/16 to 8 inclusive of material thickness as prescribed
byPart F of the AWS D1.12008 code. (herein referenced as the code)
1.2.Limitations
1.2.1. This procedure is not intended for the inspection of tube-to-tube (tubular)
T, Y, K connections
1.2.2. This procedure is not intended for the inspection of base material.
However, discontinuities discovered in the adjacent base material shall be
reported to the Owner / Engineer for disposition.
1.2.3. As a supplement to the method(s) described herein, RT is recommended
for the detection of piping porosity in ESW, and EGW weldament.
1.2.4. For discrepancies between this procedure, and the code, the code shall
hold precedence.
2. References
2.1.American Welding SocietyAWS D1.1 Structural Welding Code Steel
2.2.American Society for Nondestructive Testing (ASNT) - SNT-TC-1A Personnel
Qualifications
2.3.GE Inspection Technologies (GEIT) - Phasor Owner Manual.
(www.geinspectiontechnologies.com)
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3. Personnel
3.1. Personnel shall be certified in accordance with the ASNT SNT-TC-1A, or be
certified in accordance with the employers written practice. Provided that the
employers written practice contains, as a minimum, the requirements of SNT-
TC-1A.
3.2.Personnel performing exams shall be a certified level I, II, or a level III who has
taken, and passed a Level II Practical certification test.
3.2.1. Level I personnel shall only perform exams under the direct supervision
of a level II, or III, and shall not independently (1) conduct exams, (2)
interpret exam results, or (3) write a report of exam results.
3.3.All personnel conducting exams in accordance with this procedure shall
demonstrate proficiency by successfully passing a general, specific and
practical exam administered by a level III, or a Level II so designated by a level
III, and applying the methodology of this procedure and the rules of AWS D1.1.
4. Equipment
4.1.The ultrasonic instrument shall be the Phasor XS.
4.1.1. For compliance with Sec. 6.22 of the AWS code, reference the Phasor
Owners Manual for the technical specifications.
4.2.The search unit shall be comprised of transducer model # 115-000-866,
coupled to wedge # 118-350-037 for straight beam, or the standard 60 AWS
wedge for angle beam. The use of other search units by engineer approval is
not addressed within this document.
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4.3.The International Institute of Welding (IIW) Type 1 or Type 2 ultrasonic
reference block(s) shall be used for distance and sensitivity calibration, a
drawing of which can be found in Annex D, Drawing 2. Other approved
reference blocks (DSC, DS, and SC) may also be used, provided that the
reference sensitivity of the instrument/search unit combination is adjusted to
achieve equivalent results as that of the IIW block. Drawings for these blocks
can be found in Annex D, Drawing 4.
4.4.Any suitable couplant material of glycerin type, or a cellulose gum and water
mixture shall be used between the search unit and base material. A wetting
agent may be added to improve consistency. Light machine oil or equivalent
may be used for coupling on calibration blocks.
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5. Calibration
5.1. General
5.1.1. Reference Annex A and B for equipment qualification requirements.
5.1.2. A transducer element, cable, and coupling check shall be made prior to
an exam or series of exams, and again at the completion of an exam or
series of exams, but not to exceed intervals of 8 hours, and at any time of
suspected system irregularity. Reference Annex C for equipment
programming, and guidance.
5.1.3. The primary testing angle used for calibration shall be selected from
table 5.1
5.1.4. Calibration shall be performed with the Phasor set up in accordance with
table(s) 5.2, or 5.3.
5.1.5. Calibration intervals for sensitivity and horizontal sweep shall be made
by the operator at the location of each weld being tested, and at intervals
not to exceed 30 minutes as testing proceeds.
5.1.6. Recalibration shall be made after:
a) Change of personnel.
b) Time intervals not to exceed a maximum of 2 hours.
c) Any change to the search unit, or changing of the search unit.
d) Any disruption of the electronic circuitry. (i.e. battery swap, powerfailure)
e) Any instance of system irregularity.
5.1.7. The use of corner reflectors shall be prohibited for calibration.
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5.2. Straight beam calibration
5.2.1. With the Phasor programmed in accordance with Table 5.2, place the
search unit on face A and adjust the leg function such that 2 plate
thicknesses are displayed on the screen.
5.2.2. For sensitivity, place the search unit at a location on the base material
that is free of discontinuities. Adjust the gain control to display the first back
reflection at 50% to 75% of amplitude. (A%A reading in the results
window).
5.3. Angle beam calibration
5.3.1. A linear screen range shall be achieved to represent the actual sound
path in metal. The following method describes the use of the IIW2
reference block. However any suitable block described in 4.3 may be used.
5.3.2. Using the primary testing angle, and with the Phasor programmed in
accordance with Table 5.3, adjust the instrument to achieve a linear screen
range as follows:
5.3.2.1. Place the search unit at position D as depicted in Annex D
Drawing 1.
5.3.2.2. Adjust the leg function to display the 2 and 4 radius on the
screen, maximizing the signal(s) amplitude. (NOTE: For this
process, the Material Thickness function may also be adjusted.
However, prior to examinations, the Material Thickness function
shall be returned to the actual component thickness as prescribedin Table 5.3.)
5.3.2.3. Place the beam cursor on the primary testing angle to ensure the
readings in the Results windows are for this angle.
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5.3.2.4. In the CAL submenu (HOME > PART > CAL) adjust the gates to
surround where the beam cursor intersects the reflection from the
4 radius. (NOTE: the gates may also need to be narrowed.)
Maximize the signal response from the 4 radii by adjusting the
probe position. Adjust the gain such that the amplitude response
reads less than 100% in the A%A results window. Adjust the
VELOCITY S until the SA reading in the results window reads 4.
5.3.2.5. In the same manner as described in 5.3.2.4, adjust the PROBE
DELAY such that the SA result reads 2 for the response from the
2 radii reflector.
(NOTE: Alternately, the method described in the Phasor Owners
Manual may be used to achieve a linear screen prescribed in 5.3.2.)
5.3.3. With the Phasor programmed in accordance with table 5.3, adjust the
DbD gain control such that the response from the 0.060hole, when the
search unit is placed at position A from Annex D Drawing 1, is maximized
with the primary testing angle from Table 5.1, to display a resulting
amplitude in the A%A between 40% to 60%. The resulting DbD setting is
the zero reference level and shall be recorded on the Ultrasonic Test
Report Table 7.1 under Reference level (b).
(NOTE: The reference level may also be achieved by using only one side
of the gain in the Phasor. DbA or DbD. In this case toggle the steps key
to display the gain being used in the home screen. To activate the Level
above reference function, press and hold the orange key next to the gain
sub-menu box. In either case it is important to note the sum of all gain
applied above reference.
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Table 5.1
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Table 5.1 (cont.)
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Table 5.2
PROBE MENU
(Sub-menu) (Tab) (Value)
PRB DAT Dialog Probe Load Def
PRB GEO
Frequency 2.3 MHz
Number of Elements 16
Pitch 0.040
Elevation 0.650
WDGE DAT Element 1 Position Low end
WDGE GEO
Velocity .1086 in/s
Wedge Front 0.000
Offset Z 1.00 (Annex C)
Angle 0.0 deg
OFFSET Origin Offset 0.000
PART MENU
(Sub-menu) (Tab) (Value)
PLAN Material Thickness Enter material thickness
CAL as described in section 5.2
SCAN MENU
(Sub-menu) (Tab) (Value)
ELECTRNC
Type Linear
Focal Point Unfocused
Wave Type Longitudinal
SCN PATT
Angle Start 0.0 deg
Angle Stop 0.0 deg
Angle Step 1.0 deg
APERTURE
Number of Steps 1
First Element 1
Aperture Size 16
Aperture Step 1
DISPLAY MENU
(Sub-menu) (Tab) (Value)
VIEW
View Mode Frame
Angle corrected OnData Source Amp A
BACKGRND Color Leg On
RESULTS1
Reading 1 Beam
Readings may bedisplayed in any order
Reading 2 A%A
Reading 3 SA
Reading 4 PA
UT MENU
(Sub-menu) (Tab) (Value)
BaseDisplay Start Material
Display Delay 0.000 in
Leg 2.3
Pulser
Voltage 150V
Width 220ns
PRF Value set to maximum
ReceiverFrequency 2MHz
Ascan Rectify Fullwave
GATEMODE
Gate select Gate A
Logic Positive
Gate Display On
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Table 5.3
PROBE MENU
(Sub-menu) (Tab) (Value)
PRB DAT Dialog Probe Load Def
PRB GEO
Frequency 2.3 MHz
Number of Elements 16
Pitch 0.040
Elevation 0.650
WDGE DAT Element 1 Position Low end
WDGE GEO
Velocity .1086 in/s
Wedge Front 0.711
Offset Z 0.435 (Annex C)
Angle 47.5 deg
OFFSET Origin Offset 0.000
PART MENU
(Sub-menu) (Tab) (Value)
PLAN Material Thickness Enter material thickness
CAL as described in section 5.3
SCAN MENU
(Sub-menu) (Tab) (Value)
ELECTRNC
Type Sector
Focal Point Unfocused
Wave Type Shear
SCN PATT
Angle Start 35.0 degminimum
Angle Stop 70.0 deg
Angle Step 1.0 deg
APERTURE
Number of Steps 1
First Element 1
Aperture Size 16
Aperture Step 1
DISPLAY MENU
(Sub-menu) (Tab) (Value)
VIEW
View Mode Frame
Angle corrected OnData Source Amp A
BACKGRND Color Leg On
RESULTS1
Reading 1 Beam
Readings may be
displayed in any order
Reading 2 A%A
Reading 3 SA
Reading 4 PA
UT MENU
(Sub-menu) (Tab) (Value)
BaseDisplay Start Material
Display Delay 0.000 in
Leg 2.3
Pulser
Voltage 150V
Width 220ns
PRF Value set to maximum
ReceiverFrequency 2MHz
Ascan Rectify Fullwave
GATEMODE
Gate select Gate A
Logic Positive
Gate Display On
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6. Examination
6.1.General
6.1.1. An X line for flaw location shall be marked on the test face of the
weldament in a direction parallel to the weld axis. The location distance
perpendicular to the weld axis is based on the dimensional figures on the
detail drawing and usually falls on the centerline of the butt welds, and
always falls on the near face of the connecting member of T and corner
welds, the face opposite Face C. (see Table 5.1 for Face descriptions.)
6.1.2. A Y accompanied with a weld identification number shall be clearlymarked on the base metal adjacent to the weld being examined at the left
end on Face A (see Table 5.1 for Face descriptions.) This identification
number serves as:
a) Weld identification,
b) Identification of Face A,
c) Distance measurements and direction (+ or -) from the X line,
d) Location measurements from weld ends or edges.
6.1.3. A couplant described in 4.4 shall be used between the search unit and
scanning surface.
6.1.4. All surfaces to which the search unit(s) is applied shall be free of weld
spatter, dirt, grease, oil, paint, loose scale, or any material/condition which
would prevent the transmission of ultrasound, and shall have a contour
allowing intimate coupling.
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6.2.Base metal examination
6.2.1. The entire volume of base metal through which ultrasound must travel to
examine the weld shall be examined for laminar reflectors utilizing the
straight beam search unit calibrated in section 5.2. If any area of base
material exhibits a total loss of back wall reflection or displays an indication
equal to, or greater than the original back wall reflection height, and is
located such that its presence will interfere with the transmission of the
ultrasound for the weld inspection, its size, location, and depth from the A
Face shall be determined and reported on the ultrasonic test report, and an
alternate weld scanning procedure shall be used.
6.2.1.1. When the indication is larger than the search unit a full loss of theback wall reflection will usually occur. By sliding the search unit off
the indication until a 50% drop in amplitude from the indication is
realized, and then by measuring to the centerline of the search
unit, is generally reliable for determining the edges of the
indication.
6.2.1.2. The size evaluation of an indication which is smaller than the
search unit must be made by sliding the search unit toward theindication until a signal begins to form. At this point, the leading
edge of the search unit is indicative of the edge of the indication.
6.2.2. If all or part of the weld is deemed inaccessible due to laminar
indications, and cannot be examined in accordance with the
requirements of table 5.1, the examination shall be conducted using one
or more of the following alternate procedures, as necessary, to attain full
weld coverage.
a) Weld surfaces shall be ground flush in accordance with the
applicable paragraph(s) of the code,
b) Test from Faces A and B,
c) Utilize alternate search angles.
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6.3. Weld examination
6.3.1. Welds shall be tested with the search unit described in Section 4.2, and
calibrated in Section 5.3. Following calibration, and during testing, the
only instrument adjustment permitted is the sensitivity level (gain)
setting.
6.3.1.1. Sensitivity shall be increased from the reference level to scanning
level in accordance with scanning levels described in Table 7.5A,
or 7.5B as applicable.
6.4. Scan patterns (see Figure 6.4)
6.4.1. It is intended as a minimum that all welds are to be examined by passingsound through the entire volume of the weld and HAZ in two crossing
directions, wherever practical.
6.4.2. All butt welds shall be examined from each side of the weld axis. Corner
and T welds shall be primarily tested from one side of the weld axis only.
All Welds shall be examined using the applicable scanning pattern, or
patterns as shown in Figure 6.4, as necessary to detect both longitudinal
and transverse discontinuities.
6.4.3. To detect longitudinal defects, the following movements may be
combined from figure 6.4
6.4.3.1. Scanning Movement A, Rotation angle a = +/-10deg.
6.4.3.2. Scanning Movement B, Scanning Distance b shall be such that
the full section of the weld is being examined with the primary
angle from Section 5.3.
6.4.3.3. Scanning Movement C, Progression Distance c shall be
approximately one half the array width.
6.4.4. To detect transverse defects, cover the full weld section with one of the
following movements from Figure 6.4
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6.4.4.1. Scanning pattern D, when weld reinforcement is ground flush.
6.4.4.2. Scanning Pattern E, when weld reinforcement is not ground
flush. Scanning Angle e = 15deg. maximum.
6.4.5. For electroslag or electrogas welds, use Scanning Pattern E, with the
search unit rotation angle e between 45deg. to 60deg.
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Table 6.4
Scanning Patterns
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7. Indication Evaluation and Reporting
7.1. When a discontinuity indication appears on the screen, the maximum
attainable reflection from the indication shall be adjusted to produceamplitude equivalent to the horizontal reference level (set in Sec. 5.3.3.).
The instrument reading in dB shall be used as the Indication Level, a, for
calculating the Indication Rating, d, as shown in the ultrasonic test report
Fig 7.1.
7.2. The Attenuation Factor, c, in the ultrasonic test report shall be attained by
subtracting 1 inch of sound path (SA in the results window) from the
distance to the indication and multiplying the remainder by 2, and rounded to
the nearest dB value.
7.3. The Indication Rating, d, in the ultrasonic test report represents the
algebraic difference in decibels between the indication level with correction
for attenuation as indicated by the following expression:
Gain in dB: ac =d
(Use: abc = d if the method noted under 5.3.3. is being used)
NOTE: Traditionally the indication level a is the sum of all gain applied. For
the purpose of this document the indication level is expressed as the amount of
gain OVER the reference gain. Therefore the equation will be a c = d, and
NOT a bc = d
7.4. Lengths of indications with ratings more severe than Class D shall be
determined by measuring the distance between the transducer centerline
locations where the indication drops 50% in amplitude (6dB) below the
rating for the applicable flaw classification. The length shall be recorded as
discontinuity length on the ultrasonic test report.
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7.5. Each weld discontinuity shall be accepted or rejected on the basis of its
indication rating, and its length in conformance with the applicable Table
7.5A or 7.5B. Only those indications that are found to be unacceptable need
be recorded on the test report. The exception being those welds identified in
the contractual documents as being fracture critical. Fracture critical welds,
which are within 6dB inclusive of the minimal unacceptable rating, shall be
included on the test report.
7.6. Each unacceptable discontinuity shall be indicated on the weld by a mark
directly over the discontinuity for its entire length. The depth from the
surface and indication rating shall be clearly noted on the adjacent basemetal.
7.7. Retesting of welds that have been repaired shall be documented on a new
line in the ultrasonic report, if the original is used, and shall be designated by
an R prefix in the indication number. If additional report forms are used, the
R designation shall prefix the report number, and / or the weld number, or
any such manner that clearly identifies the weld as being previously
repaired.
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Table 7.1
Ultrasonic Report Form
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Table 7.5A
AWS D1.1 STRUCTURAL WELDING CODE STEEL
UT ACCEPTANCE-REJECTION CRITERIA (Statically Loaded Nontubular Connections)
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Table 7.5B
AWS D1.1 STRUCTURAL WELDING CODE STEEL
UT ACCEPTANCE-REJECTION CRITERIA (Cyclically Loaded Nontubular Connections)
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Annex A
dB accuracy procedure
1.dB Accuracy Procedure.
Note: In order to attain the required accuracy (+ 1%) in reading the indicationheight, the Display must be graduated vertically at 2% intervals at horizontalmidscreen. These graduations shall be placed on the Display between 60%and 100% of screen height. This may be done with use of a graduatedtransparent screen overlay. If this overlay is applied as a permanent part ofthe ultrasonic unit, care should be taken that the overlay does not obscurenormal testing displays.
(1) Program the Phasor in accordance with Table 5.2. Thencouple the straight beam search unit to the block shown inDrawing D.1 and position "T".
(2) Adjust the distance calibration so that the first 2 inch backreflection indication (hereafter called "the indication") is athorizontal mid-screen.
(3) Adjust the calibrated gain or attenuation control so that the
indication is exactly at or slightly above 40% screen height.(NOTE: the pulser voltage may be turned down if the gainvalue will not go low enough to establish a 40% value.)
(4) Move the search unit toward position U, until the indicationis at exactly 40% screen height.
(5) Increase the sound amplitude 6dB with the calibrated gainor attenuation control. The indication level theoreticallyshould be exactly 80% screen height.
(6) Record the dB reading under "a" and actual % screenheight under "b" from step 5 on Line 1 of the "UltrasonicUnit Calibration Report", Form A.1 of this annex.
(7) Move the search unit further toward position U, until theindication is exactly 40% screen height.
(8) Repeat step 5.
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(9) Repeat step 6. Except, information should be applied tothe next consecutive line on the "Ultrasonic Unit CalibrationReport", Form A.1.
(10) Repeat steps 7, 8 and 9 consecutively until the full range of
the gain control or attenuator is reached (60 dB minimum).
(11) Apply the information from Rows "a" and "b" to the belowreferenced equation (Section 2. Annex A) or thenomograph (Form A.2) to calculate the corrected dB.
(12) Apply corrected dB from step 11 to Row "c".
(13) Subtract Row "c" value from Row "a" value and apply thedifference in Row "d", dB error. These values may beeither positive or negative and should be noted with a plus
sign "+" or a minus sign "-".
(14) Information shall be tabulated on a form, includingminimum equivalent information as displayed on the"Ultrasonic Unit Calibration Report" (Form A.1) and the unitevaluated in accordance with instructions shown on thatform.
(15) Form A.2 provides a relatively simple means of evaluatingdata from item (14). Instructions for this are given in (16)through (18) below.
(16) Apply the dB information from Row "e" (Form A.1) verticallyand dB reading from Row "a" (Form A.1) horizontally as Xand Y coordinates for plotting a dB curve on Form A.2.
(17) The longest horizontal length, as represented by the dBreading difference, which can be inscribed in a rectanglerepresenting 2 dB in height, denotes the dB range in whichthe equipment meets the Code requirements. Theminimum allowable range is 60 dB.
(18) Equipment that does not meet this minimum requirementmay be used, provided correction factors are developedand used for discontinuity evaluation outside the instrumentacceptability linearity range, or the weld testing and thediscontinuity evaluation is kept within the acceptablevertical linearity range of the equipment.
Note: The dB error figures (Row d) may be used ascorrection factor figures.
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2. Decibel Equation.The following equation shall be used to calculate decibels:
dB1 = Row a
dB2 = Row c
%1 = Row b
%2 = Is the average of Row b disregarding the first andlast three tabulations
dB+%
%x20=dB 1
1
2
2
log
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Form A.1
Ultrasonic Unit Calibration Report Form
Ultrasonic Unit Model: Serial No.:
Search Unit - Size: Type: Frequency: MHZ
Calibration - Date: Interval: 2 Months Method:
Block Serial No.: Data: As Found As Adjusted
Supplemental Instructions:
Start with the lowest dB level that you can obtain a 40 percent display height indication from. Add 6 dB's andrecord this dB reading in Row A and display height Row B as the starting points on the tabulation chart.
After recording these values in Rows A and B, slide the transducer to obtain a new 40 percent display
height. Without moving the transducer add 6 dBs and record the new dB reading and the new display height inRows A and B. Repeat this step as many times as the unit allows.
Find the average % screen values from Row B by disregarding the first 3 and the last 3 tabulations. Usethis as %2in calculating the corrected reading.
The following equation is used to calculate rowc:
%1 is Row B
%2 is the average of Row B disregarding thefirst and last three tabulations.
dB1is Row A
dB2is Row C
The dB Error "Row D" is established by subtracting Row C" from Row A": (A - C = D).
The Collective dB Error "Row E" is established by starting with the dB Error "Row D" nearest to 0.0,collectively add the dB Error Row D values horizontally, placing the sub-totals in Row E".
Moving horizontally, left and right from the Average % line, find the span in which the largest and smallestCollective dB Error figures remain at or below 2 dB. Count the number of horizontal spaces of movement,subtract one, and multiply the remainder by six. This dB value is the acceptable range of the unit.
In order to establish the acceptable range graphically, Form D-9 from AWS D1.1 may be used as follows:
(1) Apply the collective dB Error Row E values vertically on the horizontal offset coinciding with the dB readingvalues from "Row A".
(2) Establish a curve line passing through this series of points.
(3) Apply a 2 dB high horizontal window over this curve positioned vertically so that the longest section iscompletely encompassed within the 2 dB Error height.
(4) This window length represents the acceptable dB range of the unit.
dB+%
%x20=dB 1
1
2
2
log
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Ultrasonic Unit Calibration Report Form A.1 (cont.)
NUMBER 1 2 3 4 5 6 7 8 9 10 11 12 13
Row A dB READING
Row B DISPLAY HEIGHT
Row C CORRECTED READING
Row D dB ERROR
Row E COLLECTIVE dB ERROR
Accuracy Required: Minimum allowable Range is 60 dB. %2(Average) %
Equipment is: Acceptable for Use Not Acceptable for Use Recalibration Due Date:
Total qualified range dB to dB = dB Total error dB (From the Chart above)
Total qualified range dB to dB = dB Total error dB (From AWS Form D-9)
Calibrated by: Level: Location:
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Form A.2
dB Accuracy Evaluation Report Form
Ultrasonic Unit Model: Serial No.:
Search Unit - Size: Type: Frequency: MHZ.
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Annex B
Horizontal Linearity, Internal Reflectors, and Resolution
1. Horizontal Linearity Procedure.1.1 This qualification procedure is performed with the straight beam
search unit, which produces longitudinal wave with a sound velocityof almost double that of shear wave. It is necessary to double theshear wave distance ranges to be used in applying this procedure.Example:
The use of a 10 in. [250 mm] screen calibration in shear wave wouldrequire a 20 in. [500 mm] screen calibration for this qualification procedure.
The following procedure shall be used for instrument certification:
(1) Couple a straight beam search unit meeting the requirementsof paragraph 4.2 to the DS block (Drawing D.1 in Position U).
(2) To attain a 20 in. [500 mm] screen calibration, adjust the firstand fifth back reflections to their proper locations with use ofthe distance calibration and zero delay adjustments.
(3) Each indication shall be adjusted to reference level with thegain or attenuation control for horizontal location examination.
(4) Each intermediate trace deflection location shall be correctwith +2% of the screen width. With the display width at 20 in.[500 mm] the +2% would be equivalent to +.400 in. [10 mm].
2. Internal Reflections Procedure.(1) Calibrate the equipment in accordance with 5.3
(2) Remove the search unit from the calibration block withoutchanging any other equipment adjustments.
(3) Increase the calibrated gain or attenuation 20 dB more
sensitive than reference level.
(4) The screen area beyond 1/2 in. [12 mm] sound path andabove reference level height shall be free of any indication.
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3. Resolution Requirements.3.1 The combination of search unit and instrument shall resolve three holes
in the RC resolution reference test block shown in Drawing D.1, or D.3.The search unit position(s) from Drawing D.1 are as follows:
(1) The 45 degree shall be placed at position S.
(2) The 60 degree shall be placed at position R.
(3) The 70 degree shall be placed at position Q.
3.2 The resolution shall be evaluated with the instrument controls set atnormal test settings and with indications from the holes brought tomidscreen height. Resolution shall be sufficient to distinguish at least
the peaks of indications from the three holes. Use of the RC resolutionreference block for calibration shall be prohibited. Each combination ofinstrument search unit (shoe and transducer) shall be checked prior toits initial use. This equipment verification shall be done initially witheach search unit and UT unit combination. The verification need not bedone again provided documentation is maintained that records thefollowing items:
(1) UT machines make, model and serial number.
(2) Search units manufacturer, type, size, angle, and serial
number.
(3) Date of verification and technicians name.
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Form B.1
Ultrasonic Unit Calibration Report Form B.1
Ultrasonic Unit Model: Serial No:
Search Unit - Size: Type: Frequency: MHZ
DS Block Serial No: Calibration Interval: 40 hours use
Horizontal linearity :
INDICATION
NUMBER
LOCATION ACCEPTABLE
RANGE
ACTUAL
LOCATION
1 4.0" 3.6 to 4.4
2 8.0" 7.6 to 8.4
3 12.0" 11.6 to 12.4
4 16.0" 15.6 to 16.4
5 20.0" 19.6 to 20.4
Internal Reflections:
IIW Block SN: Reference Level: dB
Remove search unit from block without changing any equipment settings
Increase the calibrated gain 20 dB more sensitive than reference level
Is the CRT screen area beyond 1/2" sound path and above reference level height free of
any indications? Yes: No:___
Equipment Status:
As Found As Adjusted
Not Acceptable for Use Acceptable for Use
Calibrated By: Level: Date:_____________
Reviewed By: Location:____________________
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Form B.2
Ultrasonic Unit Resolution Report Form B.2
Ultrasonic Unit Model: Serial No:___________________________
IIW Block Serial No: Resolution Block Serial No:_____________
RESOLUTION REQUIREMENTS:
Longitudinal Mode - Transducer and instrument shall resolve all 3 distances
Shear Wave Mode - Transducer and instrument shall resolve the 3 test holes
TRANSDUCERS:
Serial No. Size Type Frequency Angle(s)
Equipment is: Acceptable for Use Not Acceptable for Use_________
Performed By: Level: __ Date:_________
Reviewed By: Location:_____________________
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Annex C
Search unit check
1. This annex is written as a supplemental document to support this procedure anddescribes the method(s) to perform the following:
1) Transducer element, cable, and coupling check.2) Calculate the Z offset.
2. Due to the proximity of each element in relation to the face of the wedge (e.g. the1stelement is closer to the bottom of the wedge than the last due to the slope of the
angle.) each individual element will have a different delay in succession fromlowest to highest. To display this, program the Phasor according to the table in thisannex.2.1. Elements that do not produce a response are dead elements.
2.1.1. The number of dead elements shall not exceed more than 3 total in thearray, and no more than 2 adjacent for the array to be consideredacceptable.
2.1.2. Poor coupling will display a decrease, or lack of sound transmissionthrough all or part of the wedge. In this case remove the wedge, andre-couple the probe.
2.2. Elements that do produce a response, but appear out of sequence, or
otherwise not in line with the rest of the slope, are wired incorrectly and notfiring in the proper sequential order.
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PROBE MENU
(Sub-menu) (tab) (value)
Probe GeometryNumber of elements 16
Pitch 0.040Wedge Dat Elem 1 Pos Low End
Wedge GeometryOffset Z 0
Angle 0
Offset Probe Delay 0.000s
PART MENU
(Sub-menu) (tab) (value)
Part Velocity L .1080 in/us
SCAN MENU
(Sub-menu) (tab) (value)
Electronic
Type Linear
Focal Point Unfocused
Wave Type Longitudinal
Scan Pattern Angle Start 0.0 deg
Aperture
Number of Steps 16
First Element 1
Aperture Size 1
Aperture Step 1
DISPLAY MENU
(Sub-menu) (tab) (value)
View Angle Corrected On
Results1
Reading 1 P%A
Reading 2 PSA
Reading 3 Beam
Reading 4 SA
UT MENU
(Sub-menu) (tab) (value)
Base Display Delay 0.0
Pulser
Voltage 150V
Width 220ns
Receiver Frequency 2MHz
Gate mode TOF mode Flank
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Results for a 1D probe
The pattern created is the result of firing each individual element in sequence,and the step like slope that is created is due to the different thickness inwedge material, or delay, beneath each element.
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3. Determining the Z Offset.
Material thickness and leg functions must be adjusted to your wedge in orderto display the step pattern on the screen.
The A gate must frame the wedge echoes.
The gain must be high enough so that the P%A reading is the result of thefirst element being barely > 100% FSH.
Position the beam cursor to the last element so that it is reading in the SA.
For formulas use:
D1 = delay of first element (PSA)D2 = delay of last element (SA)N = number of elements
To determine the Z offset:
Z offset = (D1 + D2) / 2
1) Z = (9.14mm + 13.60mm) /22) Z = (22.74mm) /23) Z = 11.37mmSpecified value 11.5mm Measured value 11.37mm
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Annex D
Drawings
Drawing D.1
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Drawing D.2
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Drawing D.3
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Drawing D.4