User manual SIMRAD PI GEOMETRY DATASHEET REV A

[. . . ] Simrad PI Geometry Sensor system for trawl and danish seine Simrad's latest sensor system measures the geometry of you gear. If your trawl or danish seine is skewed and misadjusted, you will know right away! (CD012221-002) www. simrad. com TECHNOLOGY FOR SUSTAINABLE FISHERIES From the main Geometry sensor mounted on the middle of either the headrope or the footrope, you measure the distance to the two "Mini-R" responders mounted on each door or wing ends. [. . . ] This is particularly important on a bottom trawl. A skewed bottom trawl will result in unstable bottom contact, and create escape routes for fish below the gear and through the side panels. On pelagic trawls and danish seines a skewed net will make the gear unstable, and the catch be reduced. Optimal trawl geometry is therefore vital for maintaining the catch efficiency. A trawl or danish seine may be skewed for several reasons. Some of these reasons are: · Incorrectriggingoftrawl, sweep lines or trawl doors · Misadjustedwarplengths · Sidecurrent · Towinginsteeporslopededges If the rigging of the trawl is correct, you can easily compensate for skew by adjusting either port or starboard wire length. The PI Geometry sensor system is based on the fact that a correct rigged trawl and danish seine has exactly the same distance measured from the centre of the headrope or footrope to either door or trawl wing. These distances must be identical independent of weather conditions, sea state or water currents. Advantages Bottom and pelagic trawls: · Measuresifthetrawlisskewed. · Allowsyoutocorrectthetrawl geometry by adjusting the warp lengths. Danish seines: · Detectsvariationsinthedistance from the centre of the headrope (or footrope) to either wing of the seine. · Detectsdifferencesintherope lengths when the seine is closed (distances between the wings should then be close to zero). Clear and precise numerical information The numerical presentation of the PI Geometry data is automatically shown in the relevant display modes. [. . . ] The distances are changing with 0, 5 meter per minute. The graphical presentation further presents the historic values from within the past 17, 5 minutes. S1[m] 38kHz 17. 5 69. 5 2 15 X2[m] 1000W 147. 0 0. 5 12. 5 MEDIUM 10 147. 0 0. 5 T 22. 5 C 5 o S 7. 2kn 2. 5 DK 1050 m min 0 7. 5 50 100 150 200 (CD012106-001) 250 326136 / Rev. A / September 2008 Simrad Kongsberg Maritime AS Strandpromenaden 50 P. O. Box 111 N-3191 Horten, Norway Telephone: +47 33 03 40 00 Telefax: +47 33 04 29 87 www. simrad. com simrad. sales@simrad. com [. . . ]