Using the 'Gamm@chek' FMD system, an exclusive, modular, adjustable 'yolk' style frame is attached to an ROV and positioned such that a
small gamma source and a specifically designed gamma detector are on opposite sides of the structural member under test.
A calibrated gamma beam is then passed through the target component, and the extent of attenuation of the gamma beam is
measured and used to determine the presence, or otherwise, of water within the component.
Each reading takes just a few seconds and a bespoke software package is used to record and analyse the results, and to produce reports.
This slideshow displays results from an actual survey and are typical of those routinely achieved.
Click on the image above to view the slideshow
The total lack of ambiguity between flooded (100%), partially flooded (17%) and 100% dry results is clearly illustrated.
Background information: the member under test had an O.D. of 1000 mm and a nominal wall-
The survey utilised a 185 MBq Caesium-
The system is equally at home on either iROV or WROV and can also be deployed by an inspection diver.