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TABLE 14. MINIMUM REQUIREMENTS OF ISO/DIS 17636-2 (TESTING CLASS A) ON IQI
REQUIREMENTS FOR DIGITAL RADIOGRAPHY (cont.)
Wire number,
Specified wall
Specified wall
Hole number,
diameter (mm)
thickness, t (mm)
thickness, t (mm) diameter (mm)
2 < t ≤ 3.5
3.5 < t ≤ 5
5<t≤7
7 < t ≤ 10
10 < t ≤ 15
15 < t ≤ 25
25 < t ≤ 32
32 < t ≤ 40
40 < t ≤ 55
55 < t
W16,
0.10
W15,
0.13
W14,
0.16
W13,
0.20
W12,
0.25
W11,
0.32
W10,
0.40
W9,
0.50
W8,
0.63
W7,
0.80
3.5 < t ≤ 6
6 < t ≤ 10
10 < t ≤ 15
15 < t ≤ 24
24 < t ≤ 30
30 < t ≤ 40
40 < t ≤ 60
60 < t
H5,
0.32
H6,
0.40
H7,
0.50
H8,
0.64
H9,
0.80
H10,
1.00
H11,
1.25
H12,
1.60
Specified wall
thickness, t
(mm)
5 < t ≤ 10
10 < t ≤ 25
25 < t ≤ 55
55 < t
Duplex IQI
Wire diameter and
Unsharpness
spacing (mm)
D9
0.130
0.26
D8
0.160
0.32
D7
0.200
0.40
D6
0.250
0.50
a
b
b
Duplex IQI should be used in conjunction with either a wire or step/hole IQI.
Duplex IQI should be examined using a profile display; the largest wires which have a dip separation below 20% between the
wire pair determine the unsharpness.
a
b
4.7.2.3.Duplex wire IQI in accordance with ASTM E 2002 or ISO 19232-5 or EN 462-5
The first unresolved wire pair is to be achieved in accordance with Table 14. The IQI (Fig. 35) is to be
positioned nearest to the weld but slightly tilted by about 2–5° to the horizontal or vertical detector orientation.
FIG. 35. Duplex wire type image quality indicator.
4.7.3. Magnification technique
If the required duplex wire indicated in Table 14 cannot be achieved and the compensation cannot be applied,
a magnification technique is recommended. Before this is used, it is to be determined whether the focal spot and
distance cause additional unsharpness. A larger source to detector distance and a smaller focal spot will reduce the
unsharpness.
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