Geometrics G-882 User Manual

Geometrics Inc. G-882 Cesium Marine Magnetometer Page 31
This roll angle is set by
the position of the keel
weight on the tow fish
body in relation to the
“T” containing the
sensor. To change this
angle, loosen the three
clamping screws at the
top of the clamp and
rotate the keel weight to
the desired position and
then tighten the
clamping screws (Figure
33)
NOTE: In current
design, the carrying
handle attaches directly
to the keel weight so
that loosening the
carrying handle will also
loosen the keel weight allowing rotation of the weight and handle at one time.
If a echo-sounder Altimeter is employed, then you will need to rotate the nose of
the fish also to keep the altimeter pointed towards the sea floor. Simply remove
the nose top cover and loosen the clamping screws (Figure 32) and rotate the
nose to line up the altimeter with the orientation weight. Retighten the nose
clamp screws and you are done. (Note: Do not remove the red trimmer string
that attaches the nose to the fish body unless you are replacing the nosepiece).
4.3.1 Sensor Positioning in Relation to the Dip Angle of the
Survey Area
Optimal positioning the G−882 cesium sensor is necessary to insure that the best
performance will be obtained for any given survey area. To accomplish this, we
recommend that the sensor be oriented such that the Earth’s magnetic field lines
(H field) are centered in its active zone. We also want the orientation to provide
nearly equal performance in all four towing directions (forward and reverse of two
orthogonal towing directions for tie lines) to facilitate a methodical survey plan.
To get information about sensor orientation we suggest you use the program
CSAZ available from our website and on the Magnetometer CD for complete
worldwide survey recommendations.
Figure 33
7/16" Wrench
3/16" HEX L-
Key
Loosen these
three screws
to rotate the
keel weight.

Geometrics G-882 Specifications

General

Brand	Geometrics
Model	G-882
Category	Marine Equipment
Language	English