How to select an IQI?

In radiography film interpretation, sensitivity is decided by the number of wires of wire type IQI (or holes in case of hole type IQI) that are seen on the area of interest.

Every radiography film interpreter ensures that the required wires, as per code, are there in the area of interest. It is also ensured that the proper set of ASTM wires (or DIN wires) are used.

How many interpreters ensures that correct MOC of ASTM (or DIN) wires are used for radiography?

IQI is a set of wires arranged in an increasing order of their diameter and encapsulated between clear 'VINYL' plastic.

For the use of IQI, materials are grouped and for each group one material is identified for the prepration of IQI.

Materials have been designated in eight groups based on their radiographic absorption chatacteristics.

Light metal group:

Magnesium - Group number 03

Aluminium - Group number 02

Titanium - Group Number 01

The order of the group is 03, 02, 01 This order is based on the increasing order of radiation absorption. That means group 01 materials are having more radiation absorption properties than 03 group.

Heavy metal group:

Group numbers from 1 to 5, this group is also in the increasing order of radiation absorption. That means group 05 materials are having more radiation absorption properties than 01 group.

The group number, the materials representing each group number and the MOC of IQI for each group number are given in the below table. Select the proper IQI from the table below.

A detailed list of selection of IQI and grouping of materials are given on SE-747, Article 22 of ASME BPVC Sec V. The material of IQI can be identified from the group number in the IQI as in the image below.