NorthStar 972 Quickstart Manual And Reference Manual page 129

Maintaining the transducer
Do not expose a transducer to gasoline or
clean it with strong solvents, as either of
these can penetrate and degrade the
housing. If a transducer will be exposed to
salt water, coat it with anti-fouling paint to
prevent sea growth. To clean a transducer
of sand, debris, or sea growth, use a stiff
brush or putty knife. If necessary, wet-sand
with finer grade wet or dry paper. Use
sanding sparingly, as repeated sanding may
affect a transducer's performance at high
speeds. Check the transducer periodically.
Additional information can be found on
Airmar's website:
www.airmar.com
Reference section 7 — Echo sounding
125
Reference Manual Revision B
Troubleshooting the echo sounder