Simrad PI32 BOTTOM SENSOR Quick reference guide

Contact -

bottom sensors can detect bottom contact with a precision of just a few centimeters when

correct stay and detection chain lengths are used. Optimal sensor performance requires that these

lengths are configured with regard to both each other and the gear in use (the standard delivery

includes a 63 cm stay and 39 cm detection chain for use with 14 to 16 inch bobbins or rock hoppers).

Configuration -

the desired bottom detection distance is relative to the diameter of

the rock hoppers, bobbins or other gear in use. This relationship can be determined

and precise stay and detection chain length adjustments made as described below.

Setup

- lay the bottom sensor on an elevated surface and observe detection wire movement while

simulating bottom contact by raising the weight. Adjust the detection chain length as necessary. Tilt the

weight approximately 25°(

is due to drag through the water) opposite the towed direction and adjust

the stay length so that it begins to be taught. Avoid extra links at the weight ends when shorting chains.

IMPORTANT: Weights must be removed from a bottom sensors with a long stays and detection

chains before they transit the drum when hauling to prevent damage.

To attach a PI32 Bottom sensor:

two strops attached to karabiners on either side to its “top”. The strops should create a bridle about

2.) Bend the penetration ring for the detection wire about 30 cm below the footrope as illustrated.

Attach the bottom sensor and check that its feeler strap passes through the centre of the penetration

ring. Remove the netting on the inside of the penetration ring.

3.) Attach the rubber strops so that the bottom sensor is held horizontally when towed.

IMPORTANT: Carefully attach the sensor to the inside of the trawl so that it is not subject to

damage or torn off during fishing operations. The sensor’s feeler strap must always be allowed to

pass freely through the centre of the penetration ring when it is deployed.

Rock hopper,

bobbins, etc.

Attachment ring for the

stay bent securely to the

“bottom”of the footrope.

Karabiners are bent securely to the “top” of the footrope. If the bottom sensor is

attached to the wings, the length of the lashings must be adjusted so that the sensor

points toward the mother vessel when towed.

Penetration ring for

the feeler strap.

Weight and stay hang

freely under the trawl.

30 cm

Touch Down

Feeler strap

Detection

chain

Weight

Stay

Rock hopper

Bottom

End link

Note 1

Note 1:

The stay can also be attached to the steel spacer between the bobbins/rock

hopper if the footrope is held fairly stable relative to the gear.