Ultrasonic Thickness Meter
The Tritex 5600 is a multiple echo ultrasonic thickness meter. Being a 'multiple echo' tester, it can record reliable readings through coatings such as paint and antifoul making it a faster, cleaner and far less destructive tool than other ultrasonic thickness meters.
The unit is calibrated to record the thickness of different metals and alloys by calculating the recorded echo with the speed of sound through the material that is being tested.
This is mostly used to ascertain the thickness of hull plating. Multiple recordings offer insight into the general corrosion / wastage of the material, and from here any areas of thinner plating or a higher than average number of pits can be investigated.
As a general rule, one reading is taken for every square metre (m2) of hull, however, it is important that problem areas such as the 'wind and water' (waterline), around the stern gear, and the bilges be closely inspected as these areas are subject to greater corrosion than elsewhere. The waterline offers constant oxygen, dampness and light to promote corrosion, the stern gear is constructed of more noble metals than the typical hull plating leading to galvanic corrosion if the sacrificial anode is poorly bonded or non existent, and fresh water in the bilge increases corrosion on the inboard face of the plating.
The thickness meter is used in conjunction with a large hammer and a chipping hammer. Sounding the large hammer against the hull the audible return can tell an experienced surveyor the general thickness of the plating. A chipping hammer can be employed where meter readings become worryingly thin, and pitting that breaches the plating is suspected.
The cross examination of the hull with these interchangeable tests provides more reliable, factual results, and creates a far greater understanding of the condition of the hull as a whole, which in turn means better service for the client.