Corrosion testing probes ROV-II™ CP probe Operation manual Twin reference electrodes for online calibration Can be used with ROVs or as a diver-held probe Works as either a contact or proximity probe Use with Polatrak Deep C Meter™ for subsea readout Deepwater Corrosion Services Inc. | 10851 Train Court, Houston, TX 77041 USA +1 (713) 983 7117 | Email: sales@stoprust.com | polatrak.com © 2013 Deepwater Corrosion Services Inc.
ROV-II operation manual Table of contents 1. ROV-II components 3 2.1 2. Reference documents 4 MSDS sheets 4 3. Health and safety 4 4.1 4. Installation procedure 4 Dive spread 4 4.2 ROV installation 5 4.3 Cautionary notes 5 5. Calibration 6 5.1 General 6 5.2 Using calibration for troubleshooting 6 5.3 Topside/bucket calibration 6 5.4 Subsea calibration 7 5.5 Proximity mode ground check 8 6. Operation 8 6.
ROV-II operation manual ROV-II™ Tip Components Nose cone assembly An offshore case is provided with the ROV-II. The case can be filled with seawater so that the probe can be calibrated. Housing Reference electrode element Whip SEA CON® RMG-3FS connector T-handle probe mounts are available for use with ROVs. There’s a stainless steel version (above right) with a shock absorber to protect the probe during stabbing, and another made of Delrin so inspection-class ROVs can handle their weight.
ROV-II operation manual 2. Reference documents 2.1 MSDS sheets 2.1.1 Dow Corning – 4 Electrical Insulating Compound MSDS – connector sealant http://www.dowcorning.com/applications/search/products/details.aspx?prod=01903128&type=prod PLEASE CONTACT YOUR POLATRAK REPRESENTATIVE FOR ANY QUESTIONS AND/OR ISSUES REGARDING THIS MANUAL. 3.
ROV-II operation manual 4.2 ROV installation 4.2.1 The probe is best installed in or on a manipulator but may be attached directly to the ROV frame if there is no manipulator available. (This should be done when only proximity readings are required). 4.2.2 The recessed grooves in the probe body may be used to accommodate stainless steel hose clamps for attachment. We recommend installing neoprene rubber pads between the probe and the mounting surfaces and attaching a safety line to the probe.
ROV-II operation manual 5. Calibration 5.1 General As with any subsea measurement device, it is important to calibrate the ROV-II probe to ensure that the reference electrodes are working properly and that there is no damage to the probe. If the probe is not calibrated, readings may be incorrect and the dive may have to be repeated. Since the ROV-II probe uses two reference electrodes, the user always has two independent voltage readings of the tip contact.
ROV-II operation manual 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.
ROV-II operation manual • Stab the probe onto the structure and determine which reading displays the most positive voltage; this is normally the failed reference electrode. The good reference electrode will have the most negative reading. For example, (-) 900 mV is more negative than (-) 800 mV. (-) 900 mV would indicate the good reference electrode; (-) 800 mV would indicate the failed reference electrode. • Record the cell-to-cell value.
ROV-II operation manual 7. Taking cathodic protection potential readings Stab the tip-contact probe onto the point on the structure where the reading is required. When a good contact is made, the displays will show a steady reading. CAUTIONS • Avoid stabbing painted or coated surfaces whenever possible. Try to take readings on bare steel or on spots specially designated for cathodic protection measurement. • If necessary, anodes can be stabbed. However, it is best to stab the anode band if possible.
ROV-II operation manual 9. Maintenance and repair This section covers general operational maintenance. Do not attempt any task not described in this section, as it may damage the system. 9.1 Tip replacement From time to time it will be necessary to replace tips. Remove the old tip with a 7/16 in. wrench (flats are best). Avoid using an adjustable wrench if possible. Ensure that the new tip is tight. CAUTION: The contact tip has been machined to a very sharp point to enable easier readings through coatings.
ROV-II operation manual 10. Troubleshooting 10.1 The cell-to-cell value is greater than 5 mV topside or 10 mV subsea The problem could be one of the following: • One reference electrode has failed. Repeat the bucket calibration (section 5.3). The electrode with the more positive reading is probably in error. Replace the reference electrode element (section 9.2). • There is damage to the tail assembly cable or umbilical cable.
ROV-II operation manual Figure 4 Cell to Zn coupon ROV-II calibration wiring schematic Calibration voltmeter display at 2 Volts DC setting Seawater solution Non-metallic bucket Zn calibration coupon Step +VE —VE DC scale Expected result 01 Tip / Pin 1 Reference electrode 2 / Pin 3 2V –1.030 to –1.070 02 Tip / Pin 1 Reference electrode 1 / Pin 2 2V –1.030 to –1.070 (Readings should be within ±0.005V of each other) www.polatrak.
ROV-II operation manual Figure 5 Cell to cell ROV-II calibration wiring schematic Calibration voltmeter display at 200 mV DC setting Seawater solution Non-metallic bucket Step +VE —VE DC scale Expected result 01 Pin 3 Reference electrode 1 / Pin 2 200 mV ±5.0 mV 02 Pin 2 Reference electrode 2 / Pin 3 200 mV ±5.0 mV www.polatrak.com | 10851 Train Court, Houston, TX 77041 USA | Telephone: +1 (713) 983 7117 | Email: sales@stoprust.com © 2013 Deepwater Corrosion Services Inc.
ROV-II operation manual Figure 6 Cell to Ag/AgCI master ROV-II calibration wiring schematic Note: This calibration procedure is only performed by qualified Polatrak technicians before shipment or during repair. Calibration voltmeter display at 200 mV DC setting Seawater solution Non-metallic bucket Ag/AgCI master electrode Step +VE —VE DC scale Expected result 01 Master Reference electrode 1 / Pin 2 200 mV 0 mV ± 5.0 mV 02 Master Reference electrode 2 / Pin 3 200 mV ±5.
ROV-II operation manual Figure 7 Wiring for diver-assisted platform survey ROV-II wiring schematic Survey voltmeter display at 2 Volts DC setting www.polatrak.com | 10851 Train Court, Houston, TX 77041 USA | Telephone: +1 (713) 983 7117 | Email: sales@stoprust.com © 2013 Deepwater Corrosion Services Inc. Specifications subject to change without notice 15 Document 354-MN01-ENG Rev.
ROV-II operation manual Figure 8 Wiring for Deep C Meter™ readout ROV-II wiring schematic SEA CON® connector Pin 1: Contact tip Pin 2: Reference electrode #1 (R1) Pin 3: Reference electrode #2 (R2) www.polatrak.com | 10851 Train Court, Houston, TX 77041 USA | Telephone: +1 (713) 983 7117 | Email: sales@stoprust.com © 2013 Deepwater Corrosion Services Inc. Specifications subject to change without notice 16 Document 354-MN01-ENG Rev.
