The Marport Speed Explorer grid sensor is placed on the grid of a trawl. It tells you if the grid does its job: selecting out the unwanted catch while target species enter the codend. It monitors the angle of the grid and the flow of water passing through it. This way, you know if the grid is twisted or blocked and you can fix the problem before losing significant catches.
The Trawl Speed sensor can be placed on the headrope. It measures water flow in two axis: the flow along the direction of the trawl and across it. You can control if the trawl is moving at the right speed and with the right geometry. It measures along speed up to 6 knots and cross currents speed up to 3 knots.
The Symmetry sensor is placed on the headrope. It measures the across speed, so that you can control if the trawl is perpendicular to the current.
Finally, the Speed Explorer has the functions of a Trawl Speed sensor and a Trawl Explorer sensor combined. Placed on the headrope or tunnel, it measures water flow along the direction of the trawl (up to 10 knots) and across it (up to 3 knots) and displays an echogram. This way, you can see fish passing through the trawl and have an overview of the trawl’s opening and the effects of the currents around it. It also track pitch & roll, depth and temperature data. Data is received more often than with the other speed sensors.
Speed sensors are compatible with Scantrol software.