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US 5,347,860 AGranted
Benthic sampling effectiveness measurer
OwnerJ. Patton Rimerinventor
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OwnerJ. Patton Rimerinventor
Estimating the term…
This invention provides a device and method for measurement of the actual on-bottom time of a sampling otter trawl used for benthic sampling. The device uses passive measurement of the actual on-bottom time without cables and wires connected to the ship, and is small enough to be mounted on a standard otter trawl door without affecting its net-towing function. The apparatus consists of a sealed bottom contacting and counting sensor which totalizes and displays the accumulated on-bottom time. Power is supplied from a self-contained battery which may be automatically recharged by a solar cell. In operation, a flexible trigger arm is mounted so as to extend below the runner on the bottom edge of the trawl door. When bottom contact is first made, the trigger arm bends and mechanically causes a magnet to move sufficiently close to actuate a magnetic switch inside a transparent electronic data module. An electronic counter inside the module will count minutes and seconds as long as the magnetic switch is closed. Whenever the spring loaded trigger arm lifts off the bottom, the counter will stop. Actual elapsed bottom time may be read from a liquid crystal display (LCD) through the transparent case after a run. The counter may be reset to zero prior to the next trawl by waving a magnet across the module face, or the time may be allowed to accumulate. The unit has been built and experimentally tested in Southern California waters, during which it was found that the device is very useful for trouble shooting and for making adjustments for weather conditions, bottom currents, trawling direction and scope length. Also, when the net fouls or picks up large debris, intelligent decisions may be made as to whether the trawl bottom time has been impacted.
An improved water bottom contacting trawl door for towing a trawl net and including a body section having separate top and bottom edge portions, the latter riding upon the water bottom, wherein the improvement comprises:
A system for measurement of the total on-bottom time that an object with a body section having upper and lower portions thereof, being towed behind a boat is in actual contact with the water bottom, comprising:
A method for measurement of the total on-bottom time that a boat towed object having a body section with upper and lower portions thereon, is in actual contact with the water bottom, comprising the steps of:
Dependencies are inferred from the claim text.