WorkHorse H-ADCP Operation Manual
May
2015
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Page 51
H-ADCP Re-assembly
To replace the end-cap and housing assembly, proceed as follows. Use
for parts
identification.
1. Make sure all printed circuit boards, spacers, cables, and screws have been installed.
2. Install two fresh bags of desiccant just before closing the H-ADCP (see
).
O-ring Inspection and Replacement
This section explains how to inspect/replace the H-ADCP O-rings. A successful deployment depends on
the condition of two O-rings and their retaining grooves. See
for the locations of
the following O-rings. Read all instructions before doing the required actions.
300 and 600 kHz H-ADCPs
•
Transducer assembly, face, 2-260
300 kHz Narrow Beam Width H-ADCP
•
Transducer assembly, face, 2-260
•
Transducer assembly, bore , 2-258
•
Transducer assembly, par-bak 8-258
The backup O-ring is installed on 300 kHz Narrow Beam Width systems in addition to the 2-258
bore O-ring on the transducer head assembly. Install the backup O-ring with the cupped side
facing the 2-258 bore seal O-ring.
TRDI strongly recommends replacing these O-rings whenever you disassemble the H-ADCP. Inspecting
and replacing the O-rings should be the last maintenance task done before sealing the H-ADCP.
TRDI recommends you use new O-rings if you are preparing for a deployment.
To replace the O-Ring:
1. Inspect the O-rings. When viewed with an unaided eye, the O-rings must be free of cuts, indenta-
tions, abrasions, foreign matter, and flow marks. The O-ring must be smooth and uniform in ap-
pearance. Defects must be less than 0.1 mm (0.004 in.).
If the O-ring appears compressed from prior use, replace it. Weak or damaged O-rings will
cause the H-ADCP to flood.
2. Clean and inspect the O-ring grooves. Be sure the grooves are free of foreign matter, scratches, in-
dentations, corrosion, and pitting. Run your fingernail across damaged areas. If you cannot feel
the defect, the damage may be minor; otherwise, the damage may need repair.
Check the O-ring groove thoroughly. Any foreign matter in the O-ring groove will cause the H-
ADCP to flood.
3. If a scratch is on the housing flange O-ring groove, it may be gently sanded using 600-grit (wet)
sandpaper. Use care not to cause further damage.
4. Lubricate the O-ring with a thin coat of silicone lubricant (Table 2, item 5). Apply the lubricant us-
ing latex gloves. Do not let loose fibers or lint stick to the O-ring. Fibers can provide a leakage
path.