CTD-N Technical Manual
page 72
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
*The measurement error band of the CTD will widen over time due to component aging.
This effect happens regardless of whether or not the instrument is being operated. Due to
the stringent accuracy specifications, the effects of drift rapidly become a significant por-
tion of the overall instrument error budget. For example, the error band for the conductiv-
ity measurement will reach twice its initial value three months after calibration. Periodic
recalibration of the instrument is recommended to return to the original error band.
Factory Maintenance
Item
TRDI Recommended Period
RTC Battery Replace-
ment
3 to 4 years maximum: return to manufacturer for replacement.
Housing/End Caps
3 to 5 years maximum: return to manufacturer for inspection,
shorter periods may be required depending on marine growth.
O-rings
3 to 5 years maximum: return to manufacturer for replacement.
Connector
3 to 5 years maximum: return to manufacturer for replacement.
Cleaning and Inspecting the CTD-N
To remove foreign matter and biofouling:
1. Remove soft-bodied marine growth or foreign matter with soapy water. Waterless hand
cleaners remove most petroleum-based fouling. If there is heavy fouling or marine growth,
TRDI recommends soaking the affected areas in a 50:50 bath of fresh water and apple cider
vinegar for one to two hours to break down the shell-like parts. Use a wooden dowel to care-
fully break up larger pieces of the shells. Scrubbing with a medium stiffness brush usually
removes the remaining soft-bodied parts.
Do NOT use power scrubbers, abrasive cleansers, scouring pads, high-pressure marine clean-
ing systems or brushes stiffer than hand cleaning brushes as this can scratch surfaces and
damage softer parts like urethanes and sealants used in the construction of the system.
Do NOT use excessive force when breaking up larger pieces of shells or you risk damaging the
sensitive components on the external or inside of the system.
2. Rinse with fresh water to remove soap or apple cider vinegar residue.
3. Repeat steps 1 – 3, as required to remove heavy marine growth.
Do NOT soak for longer than two hours at any time and always rinse with fresh water be-
tween soakings. Soaking for longer than two hours at a time can break down the urethane
and other sealants used in the construction of the system.
4. Dry the system with low-pressure compressed air or soft lint-free towels.
