Simrad PI GEOMETRY QUICK REFERENCE GUIDE

Quick reference guide

Simrad PI Geometry

Purpose

The purpose of the Simrad PI

Geometry sensor is to monitor the

geometry of your trawl or danish seine.

This is achieved by making accurate

measurements of the distances from the

centre of the headrope (or footrope) to

each of the trawl doors or wing ends. If

these distances are not identical the trawl

(or danish seine) will be skewed and

unbalanced, and this reduces the catch

efficiency.

In order to carry out the measurements,

the PI Geometry sensor requires two

Mini-R responders, on on each trawl door

(or trawl wing).

Daily operation

Once installed and put to use, the

sensor will automatically be switched

on once the water switch is activated.

After an initial start-up, the sensor starts

transmission of the measured data it

collects.

When the sensor is not in use, check

that the sensor lamp is not flashing, as

this indicates that the sensor is active

and discharging its batteries. In this case,

wash the sensor in fresh water. You can

also apply a thin layer of silicone grease

to the sensor surface to disrupt any

residues of salt that may have built up.

If you operate with Fast update rate, the

sensor must be charged approximately

every 40 hours. Used with Normal update

rate, the operational life is approximately

60 hours. The optimal sensor charging

temperature is from +10 to +25° C.

Note: Charging sensors at sub-zero

temperatures can create explosive

gasses. Simrad assumes no liability for

the improper charging of sensors or the

use of chargers not specified in Simrad’s

sensor charging documentation.

The two rubber inserts provided at

the bottom of each responder adapter

must not be replaced with any other

types or designs. It is essential that these

inserts provide a secure cradle for the

(A) The PI Geometry sensor is mounted at the exact centre of the headrope or footrope.

(B) The two Mini-R responders are mounted on each trawl door or trawl wing.

measure the distances.

(D) The PI Geometry sensor uses an acoustic link to transmit the results from the

distance measurements to the PI system on the vessel.

Main items

(A) Negative charging & fastening lug

(B) Positive charging & fastening lug

to the responders

(D) Geometry set identification

(E) Location of water switch and sensor

identification label

responders, but they must also allow

for free water circulation to allow the

responder’s water switch to engage. Also,

the design of the inserts allows sand and

mud to flow out when the trawl doors are

pulled up from the water.

Sensor conguration

On delivery, all PI Geometry sensors are

configured as follows:

Responder: Responder 1

Distance: Channels 1 and 5 / Fast

Note: The sensor and the PI system

setup must correspond, otherwise the

communication will not work.

To change the setup, use the PI

Configurator utility.

The sensor update rate controls how

often the sensor reads and reports the

depth. Three settings are available; Fast,

Normal and Slow. Note that a faster

update rate will decrease the battery life.

Kongsberg Maritime AS Strandpromenaden 50 P. O.Box111 N-3191 Horten,Norway

Simrad

Telephone: +4733034000 Telefax: +4733042987

simrad.sales@simrad.com

www.simrad.com

Numerical presentation

X1 [m]

143.5



X2 [m]

143.



(CD012221-007)

The numerical presentation of the PI

Geometry data is automatically shown

in the relevant display modes. Since this

is a “dual” sensor two yellow rectangles

are used to indicate which two numerical

displays that provide information from the

same sensor.

When the readings are stable, the digits

are shown in black colour. If the contact is

lost, the characters *** are shown in grey.

If the distance is out of range, the display

shows: ???.

(A) Sensor identification

(B) Unit of measurement

(D) Distance change per minute

(E) Arrows pointing “out” means

that the distance is increasing,

arrows pointing “in” means that

distance is decreasing

(F) Visual alarm

(G) Sensor transmission indicator

(H) Interference warning

(I) Dual sensor identification

Installation

The PI Geometry sensor is mounted at

the exact centre of the trawl or danish

seine opening, either at the headrope at

the top of the opening, or at the footrope

at the bottom. In both locations it must

be mounted with the communication

transducers facing forward. The two

Mini-R responders are normally installed

on the trawl doors or trawl wings. From

this position, they will communicate with

the PI Geometry sensor.

Note: Ensure that you mount the PI

Geometry sensor with the transducer

opening facing forward. There must be a

clear line of sight between the transducer

on the PI Geometry sensor and the

transducers on the Mini-R responders.

The SIMRAD print on the sensor (C) must

point up towards the water surface!

(A) Forward

fastening lugs with

snap hooks and rope

(B) Aft fastening lugs

with snap hooks and

rubber bands

sensor, top

Recommended procedure

1 Assemble a bag of ne-meshed net,

and tie this bag to the trawl at the

middle of the headrope.

2 Place the sensor inside this bag.

3 Secure the two forward fastening

lugs (A) on the sensor using two

snap hooks and rope.

4 Secure the two aft fastening lugs (B)

on the sensor using snap hooks and

strong rubber bands. This mounting

places the sensor in a cradle

supported on all four sides.

5 Ensure that the sensor is properly

mounted. Check that it is not

permitted to move sideways during

the shing operation, as this may

lead to a communication failure.

6 Make sure that you have best

possible free view between the PI

Geometry sensor and the Mini-R

responders on the trawl doors, and

between the sensor and the vessel.

Sacricial water switch

The water switch on your sensor is

a sacrificial brass screw. The bolt will

gradually be worn out. Check it from time

to time to remove corrosion, or replace it

if necessary.

More information

Read the dedicated instruction manual

to learn more about installation, use and

maintenance of the PI Geometry sensor.

322417 / Rev.B / February 2009