Operating Manual

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ASTM 1025 IQI’s
The plaques have markings
showing their thickness in
thousandths of an inch. Ea ch
plaque has three holes of dia-
meters 1T, 2T and 4T. T being
the thickness of the plaque.
Thin plaques with T < 0.01”
form an exception to this rule.
Hole diameters for these
plaques are always 0.01”, 0.02”
and 0.04”, so do not comply
with the 1T, 2T, 4T rule.
These types of plaque are identifiable through notches cut in the edge, by which they can
also be identified on the radiograph.
Originally it was standard practice to use a plate of 2 % of the specimen thickness, but at
present 1 % and 4 % plates are used too.
If T is 2 % of the specimen thickness and the 2T hole can be seen on the radiograph, the
attained sensitivity level is said to be (2-2T), etc. Equivalent sensitivity values in percen-
tages are shown in table 3-13.
At least three sides of a penetrameter must be visible on the radiograph. The thickness of
the penetrameter in relation to the specimen thickness defines the “contrast sensitivity”.
The size of the smallest hole visible defines the “detail sensitivity”.
MIL-STD IQI’s (military standards)
In the past for some applications specific MIL-standard (MIL-STD) IQI’s should be used
only. They are very similar to ASTM IQI’s. Nowadays the MIL-STD accepts that they are
replaced by the almost identical ASTM type IQI’s providing they meet the requirements
specified in the MIL-STD. Nevertheless MIL-STD IQI’s are still available and in use.
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Table 1-13 shows the wire combinations for the four IQI’s according to EN 462-01.
The diameters of the wires are given in table 2-13.
EN-type IQI’s are manufactured with wires of steel, aluminium, titanium or copper,
depending on the type of material to be examined. On each IQI the wire material is indi-
cated. Fe for steel, Al for aluminium, Ti for titanium and Cu for copper.
13.3 List of common IQI’s
Figure 2-13 shows the five most common
IQI’s. Their origin and description can be
found in the following standards:
• EN 462-01 Europe
• BS 3971 Great Britain
• ASTM 747 USA
• ASTM 1025 USA
• AFNOR NF A 04-304 France
ASTM 747 describes the wire penetrame-
ter quite similar to wire penetrameters of
other origin. ASTM 1025 describes the
plaque penetrameter similar to AFNOR.
Both types of ASTM IQI’s have been
developed and standardised in the USA,
they now are used world-wide.
IQI Wire numbers Wire diameter from/to (mm)
1 EN 1 to 7 inclusive 3.2 to 0.80 inclusive
6 EN 6 to 12 inclusive 1 to 0.25 inclusive
10 EN 10 to 16 inclusive 0.40 to 0.10 inclusive
13 EN 13 to 19 inclusive 0.2 to 0.05 inclusive
Table 1-13. Wire IQIs according to EN 462-01.
Diameter
(mm) 3.20 2.50 2.00 1.60 1.25 1.00 0.80 0.63 0.50 0.40
Wire nr. 1 2 3 4 5 6 7 8 9 10
Diameter
(mm) 0.32 0.25 0.20 0.16 0.125 0.10 0.08 0.063 0.05
Wire no. 11 12 13 14 15 16 17 18 19
Fig. 2-13. Examples of image quality indicators
Fig. 3-13. ASTM plaque type IQI
Table 3-13. ASTM Equivalent image quality indicator
Level Equivalent (%) Level Equivalent (%)
1 - 1T 0.7 2 - 2T 2.0
1- 2T 1.0 2 - 4T 2.8
2 - 1T 1.4 4 - 2T 4.0