Reson Seabat 8101

Installation1. Stray currents may exist on the mounting structure (vessel, ROV, towbody,etc), and it is mandatory to keep the head isolated from these currents.2. Aluminum alloy has a higher electrode potential than many commonly usedstructural materials such as steel, stainless steel, and titanium; therefore thealuminum sonar housing will suffer from galvanic corrosion if in direct contactwith them while submerged in seawater.3. If the sonar head is not electrically isolated from the structure, the attachedanodes will attempt to protect the entire structure from galvanic corrosion,rather than just the sonar head. These anodes are not sized for this task, andwill erode very quickly.2.5.2 TitaniumThe optional 8101 Sonar Head housing is composed of titanium, and will notcorrode. However, RESON strongly recommends that it be installed so thatthere is complete electrical isolation between the housing and the mountingstructure. This is done for two reasons.1. Stray currents may exist on the mounting structure (vessel, ROV, towbody,etc). It is advisable to keep the head isolated from these currents.2. Due to the extremely low electrode potential of titanium, it is noble to nearlyall other metals when immersed in seawater. Therefore, if it not isolated, itcan cause galvanic corrosion of the mounting brackets and hardware, andplace an additional load on the mounting structure's sacrificial anodes, causingthem to erode very quickly.2.5.3 IsolationElectrical isolation for both the Titanium and Aluminum heads is typicallyachieved by insulating them from the mounting brackets by the use of nonconductivebushings, washers, and isolation plates. These materials can includedelrin, G-10 glass fiber sheets, and/or high-density polyethylene sheets. ContactRESON Engineering for additional information on sacrificial anodes or schemesfor electrical isolation2.6 Ping Hold-off FeatureThis paragraph applies only to systems that have Dry Firmware version 8101-2.04-83E4 installed, and not to a standard 8101 system.The addition of the “Ping Hold-off Feature” provides a method to synchronize the8101 transmissions (pings) to a external controller device. No operator action isrequired, once the appropriate signal source has been connected to the system,as described below.______________________________________________________________________SeaBat 8101 Operator's Manual 2-8 Version 3.02