This form of inspection is used to locate areas of increased temperature either associated with local overload or with increased resistance.
Infrared Temperature measurements
This takes the form of a relatively inexpensive, readily available temperature reading instrument often with laser guidance. The taking of readings is very simple although care must be taken in the interpretation of results. Due to their low cost these are normally found on most vessels as standard item Thermal imaging
These tend to be expensive specialist instruments although they may be used by untrained personnel and results are generally simple to interpret. Due to their high cost it is normal to have a single unit available for several vessels delivered as required.The unit is used rather like a video camera and the results viewed in realtime as an image displayed on the rear of the instrument.
A typical unit is that seen in common use with fire brigades who use it in search and rescues
Author Note
When carrying out a thermal imaging inspection on a cargo pump switchboard on a large LNG carrier it was noticed that the areas around the connection of two busbar sections was unusually hot
The power was isolated on the switchboard and the tightness of the joining bolt checked. It was found tight. The decision was made to investigated further and the busbar section was disassembled
It was found that a large portion of the copper material at the contact face had disintegrated and was found absent from both joining bars. The reduced area of contact led to increased resistance and thus the increase in temperature. The author is not able to offer an explanation as to the mechanism of failure of the busbar. I would suggest that the damage and been caused previously due to the bolt being loose. The bolt had been tightened without further investigation or recording of this action
When carrying out a thermal imaging inspection on a cargo pump switchboard on a large LNG carrier it was noticed that the areas around the connection of two busbar sections was unusually hot
The power was isolated on the switchboard and the tightness of the joining bolt checked. It was found tight. The decision was made to investigated further and the busbar section was disassembled
It was found that a large portion of the copper material at the contact face had disintegrated and was found absent from both joining bars. The reduced area of contact led to increased resistance and thus the increase in temperature. The author is not able to offer an explanation as to the mechanism of failure of the busbar. I would suggest that the damage and been caused previously due to the bolt being loose. The bolt had been tightened without further investigation or recording of this action
