The Poseidon Dynamic Test System
The Poseidon Dynamic Test System (PDTS) is a versatile platform that allows exposure of flat panels on a rotating frame in the middle of the sea. Supplied with electric power through an underwater cable from the shore laboratory (photo on left), the motors rotate the panels horizontally at various speeds ranging from 15 to 25 knots. The erosion rate as result of the fluid shear forces can be determined at each specific speed. The figure below shows the erosion of a self-polishing copolymer coating at different speeds.
Although static immersion test is sufficient to measure the antifouling characteristics of a particular coating, it is not as reliable in determining the performance of the entire coating system. In many cases, panels that do well under static, fail when exposed to shear stress in the PDTS machine. Testing in advance enables reformulation or redesign of the top coat, primer and application procedures to meet customer expectations.
The comparison of same coating exposed for two months in both immersion tests. The difference in the results was compelling.
POSEIDON DYNAMIC TESTING SYSTEM (PDTS) NOW ON ITS 6TH YEAR OF OPERATION
Poseidon Dynamic Testing System (PDTS) now makes it possible to simulate the erosion rate of marine coatings in a moving vessel. This new procedure enables simultaneous evaluation of the erosion rate at various fluid shear forces using flat panels. This system was presented in 2003 to the Society of Protective Coatings at its conference in New Orleans and at the Federation of Societies of Coatings Technology’s annual meeting in Philadelphia. For a PDF copy of this report, please click here.
In this procedure, flat metal panels are placed on a horizontal plane on a rotating disc immersed in the open sea, which causes erosion on the flat panel at various ship speeds of up to 40 miles per hour. The description of our marine research exposure stations and the dynamic testing system can be found in detail on the Poseidon website www.poseidonsciences.com.
The PDTS machine uses a standard flat steel panel supplied by ACT Test Panels, LLC (Michigan) with the following specifications:
As shown in the figure (above), the position of the panel in the rotating disc will determine the relative velocities of the seawater. One panel can be used for each of the three (3) positions to obtain the full range of velocities possible and to conduct the evaluation in duplicate.
Combination of Dynamic and Static Immersion Testing