Marport releases new multi-function door sensor

The sensor is part of the new MFX (Multi-Function Extended Battery) product line and has been designed using the latest software defined acoustics technology.

Every MFX sensor integrates distance measurement transducers, multiple axis accelerometers and inclinometers, digital temperature sensor, precision depth sensor, power management, embedded signal processing firmware and broadband transducers for reliable measurement and communications.

Distance sensors work in pairs (master and slave) to measure the physical distance between the trawl doors during bottom and pelagic trawling. In addition to door spread distance, the MFX Door Sensors can simultaneously measure door pitch angle, roll angle, water temperature around the door as well as depth of the trawl door. The MFX Door Sensors are the first in the industry to incorporate multi-function capability, including:

• Door Distance - door distance sensors work in pairs (master and slave) to measure the physical distance between the trawl doors during bottom and pelagic trawling

• Depth – this function measures the trawl door depth as well as the door descent/ascent rate during shooting and hauling to help place the doors at the desired depth in the water column

• Temperature - this function measures water temperature around the trawl doors in order to reduce time and fuel spent towing in waters that are not suited to the targeted species

• Roll Angle - roll angle refers to the door’s natural behaviour to lean outwards or inwards during towing

• Pitch Angle - Pitch angle is used to refer to the lifting of the door, either at the front or at the rear while being towed

The master sensor communicates with slave sensors by using a transversal wireless acoustic frequency of 30.8 kHz, 110 kHz or 144 kHz. The sensor software measures the differences in signal arrival times to calculate the distance between the various sensors. Distance information, as well as optional pitch, roll, temperature and depth measurement is wirelessly transmitted to the vessel using broadband transducers.

All of these functions can be simultaneously processed and displayed by Marport’s acoustic receiver and bridge display.

Marport’s master and slave sensors can also operate up to 200 hours on a single charge. In addition, the Active Power Management system continually measures and transmits the sensor’s remaining battery capacity to the bridge display.

The sensors are packaged in a robust housing that measures 305mm L x 142mm diameter for the master and 301mm L x 112mm diameter for the slave. The master weighs 5.4kg in air while the slave weighs 3.5kg. The sensors can be installed in standard trawl door mounting pockets.