The effects from biological growth can be seen as a decrease in the received amplitude, like an SNR problem that gradually gets worse. The fouling will in most cases not affect the current velocities, but it will reduce the range of the instrument.
Cleaning: We do not have a standard recommended transducer cleaning procedure. We realize that barnacles have to be removed mechanically, but that we strongly advise against using sharp objects capable of harming the polyurethane surface. We also recommend to stay away from strong organic solvents such as acetone. Lime dissolving liquids can be used. Avoid scrubbing and high pressure washers. For soft bodied marine growth it is recommended to use soap and water. Although realising that barnacle can offer tough resistance we would also like to stress the importance of a patient and careful approach, keeping the use of mechanical force and sharp objects/tools to a minimum.
Prevent growth: See Wiki article updated January 2020: Biofouling - how to extend your deployment
Regarding antifouling paint, the important thing is that the paint is not too thick, otherwise the signal strength will decrease. Customers should be careful not to paint any anodes (if present) and to make sure pressure ports are not blocked. Also, when painting transducers, make sure to put just one smooth coat to make sure it doesn't affect the acoustic signal. There cannot be any air bubbles trapped between the paint and the face of the transducers.
We have heard from users that use the Trilux and they report that it is a great paint and it works well on both the Delrin plastic as well as Aluminium. It also works well for epoxy transducers.
Upon request, Jotun's tip is to paint the VM profiler (with bronze alloy head) the following way:
- 100 um of Penguard base
- 100 um of Safeguard
- 300 um of Seaquantum Ultra
A couple of instruments subject to biofouling