Section 4 Fixed potential monitoring systems
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Offshore Units, July 2022 - Part 8 Corrosion Control - Chapter 2 Cathodic Protection Systems - Section 4 Fixed potential monitoring systems

Section 4 Fixed potential monitoring systems

Parent topic: Chapter 2 Cathodic Protection Systems

4.1 General

4.1.1 A permanent monitoring system is to be installed on structures protected by an impressed current cathodic protection system, and, although not essential, such a monitoring system is recommended for use in conjunction with sacrificial anodes. Monitoring schemes shall comply with BS EN 13509 – Cathodic protection measurement techniques.

4.1.2 Zinc or Ag/AgCl reference electrodes should be used. Reference electrode materials and design specified in the above standard are also permitted.

4.1.3 Variations between electrodes of ±30 mV have been reported for zinc/sea-water reference electrodes and ±5 mV for silver/silver chloride/sea-water electrodes but unless a high degree of stability is required, either electrode may be used for comparison purposes. The zinc/sea-water electrode may be taken as approximately 1,03 V more positive than the silver/silver chloride/sea-water electrode.

4.1.4 The location and attachment of the reference electrodes are to take account of the stresses in the members concerned and they should not be attached in highly stressed areas or in way of butts, seams, nodes or any stress raisers.

4.1.5 The location of the reference electrodes should be such as to enable the performance of the cathodic protection system to be adequately monitored.

4.1.6 The reference electrodes may be connected to the top side display and control equipment by suitable cabling or by any other agreed means.

4.1.7 Provision is to be made for the regular recording at an agreed interval of the potential of the steelwork and log sheets are to be made available for inspection when required by LR Surveyors.

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