Specifications

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2013 Deepwater Corrosion Services Inc. Specications subject to change without notice
ROV-II operation manual
7 Document 354-MN01-ENG Rev. C
tive lead and note the reading. Then take the negative lead and contact pin socket #3; note the
reading.
• Figure 4 shows the correct wiring schematic and the expected results. The two readings
should not be more than 5 mV apart.
• Remove the probe tip from the zinc coupon. The reading should revert to a voltage within the
range of (-) 0.200 to (-) 0.400 V DC.
5.3.5 To perform a cell-to-cell calibration:
• Using a digital voltmeter set on 200 mV DC scale, contact pin socket #2 with the positive volt-
meter lead and pin socket #3 with the negative voltmeter lead. Note the reading.
• Figure 5 shows the correct wiring schematic and the expected results. The reading should be
between ±5 mV.
Figure 2 - SEA CON® RMG-3FS connector pin diagram
5.4 Subsea calibration
The cell-to-cell value can be checked at any time while the ROV-II probe is deployed subsea.
Subsea calibration should be performed with the entire cable immersed, as it will quickly detect
any cable damage. Diver surveys using the ROV-II probe should have two topside multimeters
connected to the dive cable. ROV-assisted surveys should have the Polatrak Deep C Meter along-
side the probe to provide a subsea LED readout of the voltages. Wiring schematics for these two
options can be seen in Figures 7-8.
CAUTION
NEVER submerge any unmated Seacon connectors.
5.4.1 While the probe is free-ying subsea without contacting any metal, the voltage readings
will vary depending on ROV/diver speed, time of immersion and whether the tip contact has
recently stabbed a structure or pipe. Normally, the voltage readings will be in the range of (-) 200
to (-) 400 mV.
5.4.2 Both voltage readings should never be more than 10 mV apart while the probe is subsea.
Remember, this difference between voltage readings is the cell-to-cell value. If the cell-to-cell
value is greater than 10 mV, the cause may be:
• Lead wire is damaged, exposing copper to seawater.
• A connection is not properly mated or is leaking.
• One or more reference electrode elements has failed.
5.4.3 If it becomes apparent in the middle of an operation that one reference electrode element
has failed, it is possible to complete the dive. Follow these steps to isolate the bad reference
electrode:
Pin socket 1: Contact tip
Pin socket 2: Reference electrode #1 (R1)
Pin socket 3: Reference electrode #2 (R2)