YSI SonTek ADVField, Technical Documentation Manual

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SonTek/YSI
ADVField/Hydra Operation Manual (September 1, 2001) 87
When painting metal housings, a suitable conversion layer must be applied to the metal for adhe-
sion and to isolate the metal from the anti-fouling paint. If the metal has been powder coated (as
many ADV components are), this acts as an excellent conversion layer. If no powder coat is pre-
sent, or if the powder coating has been damaged, we suggest Interlux 360 Underwater Metal
Primer. The primer should be applied to all metal surfaces
except
transducer faces, sacrificial
zinc anodes, cable, and areas where the powder coating is in good condition. Apply the anti-
fouling paint to all surfaces of the instrument that require protection. Follow the instructions on
the paint container with the following exceptions.
•
Apply only
one
coat of anti-fouling paint to the transducers. Each layer of paint will cause
some loss in signal strength, and multiple layers can potentially affect system performance.
Ensure that the paint has a smooth, even surface with no air bubbles.
•
IMPORTANT
: Do not paint the sacrificial zinc anode. Doing so will remove all corrosion
protection.
If anti-fouling protection is desired for some portion of the cable, the paint can be applied di-
rectly to the polyurethane jacket without primer.
5.10. Routine Maintenance
The ADV is designed to provide years of reliable performance with minimal maintenance.
Unless mechanically damaged, the ADV never requires recalibration. This section provides some
general guidelines for taking care of the ADV to ensure a long life and reliable performance.
The ADV acoustic sensor should be protected from mechanical impact. If the receiver arms are
bent, the geometry of the sensor will change, and the factory-supplied calibration will no longer
be accurate. To check for sensor damage, run
ADFCHECK
on a routine basis (at the start of each
working day is a good habit). See §5.11 and the
ADVField Software Manual
for details.
The transducers are encapsulated in epoxy and generally have excellent resistance to abrasion
and normal wear and tear. If necessary, the transducers can be cleaned with a non-metallic brush.
Barnacles and other hard-shelled organisms can be carefully scraped off with a knife.
Check all o-rings and o-ring surfaces whenever opening any submergible portion of the system.
Replace old or damaged o-rings, and look for any scratches or damage to the o-ring surfaces.
For salt-water deployments, make sure all metallic parts have a zinc anode in good condition.
The outer appearance of the anode can be misleading. Scrape the anode with a screwdriver to test
its strength and replace the anode if there are any doubts.
Try to avoid water condensation on the circuit boards. Purge canisters with nitrogen if they have
been opened, and place bags of desiccant where suitable.