To measure the true potential of cathodically protected pipeline, a new probe consisting of a steel coupon and a Mixed Metal Oxide (MMO) titanium activated type, both embedded in a cementitious media, was tested in laboratory and in field. Aim of laboratory tests was to evaluate the relationship between potential and cathodic current density as a function of soil humidity. Field tests confirmed that the probe can measure continuously the true potential in all conditions, especially in presence of stray current, then avoiding the use of the on-off technique. The continuous reading of the true potential was gathered by means of a remote control system to operate CP systems in compliance with regulations and to reduce routine maintenance costs.

Subject
Steel surfaces, Water, Cathodic protection, Sand, Cathodic potential, Probes, Steel coupons, Reference electrodes, Potential measurements, Constants, Current densities, Soil, Electrode potential
Keywords:
Cathodic protection monitoring, true potential, remote control system
© 2005 Association for Materials Protection and Performance (AMPP). All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise) without the prior written permission of AMPP. Positions and opinions advanced in this work are those of the author(s) and not necessarily those of AMPP. Responsibility for the content of the work lies solely with the author(s).
2005
Association for Materials Protection and Performance (AMPP)
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