Tuesday, March 25, 2014

Angel Reef (ARTO1) Scheduled CREWS Maintenance

The Angel Reef CREWS (ARTO1) was serviced on 20/03/2014 after several months of basic maintenance. In January 2014 anomalous temperature and conductivity reading were detected and it was scheduled for maintenance in March 2014.

Pre-cal CTD

Depth: 1.11m     
Temperature: 26.98
Conductivity: 55352
Salinity: 35.14

Little fouling was noted at this site.  Mooring lines, the buoy and the hardware attached to the buoy remained intact and with no noticeable damage.  Mooring lines and the buoy  were fouled with few gooseneck barnacles, sessile barnacles and tufts of green filamentous algae.  The anchors remained intact with no cracks or weaknesses noticed.  The western most subsurface buoy has shifted up to the surface of the water, and will be adjust on next visit.

Little fouling was noted on the EXO2 and on the protective casing. Most of the copper coating surrounding the probes remained intact, but given the lenth of time since the last service they were changed.  The probes were thoroughly cleaned of all barnacles, algae and other encrustations. All debris removed from the threading and krytox gel reapplied to all ports prior to reconnection to the base unit.  On recalibration it was noted that the conductivity/temperature probe was faulty (during calibration it registered temperature of 1.xx e-9 and conductivity readings of 96500 in the conductivity standard) and has been replaced with a new probe.  The faulty probe has been sent to YSI from examination. The new probe passed calibration process.  A QC result was generated during the TSS calibration process for reasons undetermined.  This also occurred during the first installation of the CREWS.

Exterior of base of sonde on removal from CREWS

Exterior of top of sonde on removal from CREWS

Inside of protective cover of sonde on removal from CREWS

Some colonisation on sonde and state of sacrificial anode

Still intact copper coating

Some colonisers on cleaning brush and probes

barnacle growing on cleaning brush

Minor tear on copper coating