Installation Principles
Door sensors need to be installed in pockets welded on trawl doors. Carefully read these installation principles before installing sensor pockets.
Angle of Attack
![]() |
1. Angle of attack: 25-40° 2. Opening angle 25-40° |
Opening and Elevation Angles for Spread Sensors
The opening and elevation angles depend on the pocket installation on the door.
The opening angle is the horizontal angle of the pocket in relation to the door. It should be between 25° and 40°. Opening angles should be in line with the angle of attack. You need to indicate the opening angle on Mosa2.
![]() |
1. Elevation angle: 15-20° 2. Opening angle: 25-40° |
![]() |
1. Elevation angle: 15-20° |
Roll Angles for Spread Sensors
![](../img/PocketsRollAngle.png)
PRP & Digital Spread Communication
Spread sensors communicate with each other and with the receiver. Lines of communication between them and toward the receiver must be unobstructed.
![]() |
![]() |
Communication toward receiver (46°) |
![]() |
Communication between sensors (26°) | |
1. Master sensor 2. Clump sensor 3. Starboard sensor |
Door Sounder sensors do not communicate with each other, so only lines of communication toward the receiver and bottom must be unobstructed.