Operation Manual

Getting started

850-165186 / Rev.B

• Pelagic trawl: On a pelagic trawl, this sensor proves very

useful when the trawl moves downwards. It will let you

know immediately if the footrope touches bottom.

• Purse seine: When you work with a purse seine, you need to

know when the seine reaches the bottom. This sensor will let

you know. once it happens.

• Danish seine: Used on a Danish seine, the sensor will let you

know when the net has a stable bottom contact, and when it

is time to haul.

• Scientific research: During scientific surveys, an exact

definition of towed distance with proper ground gear contact

is an essential parameter in bottom trawl swept area estimates

of fish abundance. Using a Bottom Contact sensor will

reduce errors in this key parameter.

Catch sensor: When is the trawl full?

This is your “eye” at the cod-end. With PI Catch sensors in use,

you can easily monitor the fi lling rate and the amount of catch

in the trawl. Save time and fuel, haul in the trawl at the right

moment! The design is rugged and awardwinning, and the

sensor’s sensitivity is easily adjustable for trawls of all sizes.

Some professionals claim that the Catch sensor is the most

important sensor on the trawl. Why? Because it will tell you the

amount of catch in the trawl.

The sensor simply monitors the expansion of the meshes in the

cod-end. Once the volume caught is enough to expand the

meshes, they will pull the detector wires and engage the sensor.

The sensitivity of the sensor can easily be adjusted, just extend

the detection rubber bands to span additional meshes.

To monitor the filling rate, we recommend that you use

minimum two sensors. Place the first sensor at the far end of the

cod-end, it will tell you that the trawl is actually fishing. Place

the second sensor closer to the trawl opening. Once the trawl is

filled to the chosen location, the sensor is engaged, and you

know that it is time to haul.

Use the PI Catch sensor to adjust the catch volume according to

the production capacity, check that the trawl is fishing, adjust

the caught volume to secure quality, and minimize the towing

time to save fuel. These are only a few of the reasons why this

sensor is considered to be so important.