RADIOGRAPHY IQI PLACEMENT

[OrdinarylvII]

The code(Api 1104)specifies that 1 iqi is to be placed in the approximate center and 1 at the end of the FILM to be inspected (in od exceeding 5"). My guess is that the reason for the placement to be in the center of the film is due to fact that the source to film distance is the greatest in the center.My question is in a scenario where you would be using multiple sheets of film (overlapping) to cover a specific view, would you place the iqi in the center of the view (the overlapped area in a 2 sheet view) or in the center of each individual sheet of film? To me in this situation to place the iqi in centers of the film and not in the center of the view would contradict the principle of the iqi being in the area where the sensitivity is most important.

 

[SectionIX]

OrdinarylvII

The middle IQI needs to be in the center of the of the view, which should be in the overlap. This should show up on both exposures.

The other (for DWE/SWV with readable > 5 inches) is within one inch of the end of the READABLE film length.

 

[SPDL310]

If you are banding film you will require 2 IQIs one at the center of the band and one 1" from the last area of interest. For example if you are banding three pieces and shooting your 0-1 shot you would place one IQI in the center of the middle piece and the other 1" away from the 0 or 1 station. If you have an area of interest that is longer than 5" and on a single sheet of film You will also need to use two IQIs. As you have already stated this occurs in any pipe that exceeds 4.75" in outer diameter for a three shot exposure or 6.36" OD on a four shot exposure on a schedule pipe chart this translates to 4.5" nominal size and above for three shots and 6" nominal and above for four shots. If you are shooting a panoramic SWE/SWV shot covering the entire weld in one exposure you are only required to have four IQIs equally spaced around the exposure.