Keywords
Citation
(2001), "Accurate pipe to soil potential readings", Anti-Corrosion Methods and Materials, Vol. 48 No. 3. https://doi.org/10.1108/acmm.2001.12848cad.009
Publisher
:Emerald Group Publishing Limited
Copyright © 2001, MCB UP Limited
Accurate pipe to soil potential readings
Keywords BAC Corrosion Control, Cathodic protection
Recent upgrades to the BAC Corrosion Control GCU series of DC current interrupters are said to now allow more accurate, easy, versatile and economical synchronous switching of cathodic protection stations.
The GCU interrupters (Plate 2) are designed to save time during maintenance and survey periods by accurately switching "ON" and "OFF" cathodic protection DC current sources in order that the true polarised pipe to soil potential, used as a criterion for cathodic protective levels, may be recorded on the pipeline. The instant "OFF" potential is considered accurate, as it eliminates an additional voltage drop when the system is switched on and the subsequent volt drop caused by cathodic protection current flow in the soil.
Plate 2
New BAC GCU series current interrupters
The GCU series of current interrupters from BAC are supplied in three ratings to cater for most types and capacity of DC power sources: GCU15/R4 15Amp DC capacity (compatible with the GCU/R3 model); GCU25/Rl 25Amp DC capacity and GCU100/R1 100Amp DC capacity
The solid state unit uses state of the art electronics housed in a rugged 1P65 sealed enclosure built to withstand a wide range of field conditions. Control is through an easy-to read LCD menu screen which also indicates the condition of the built-in NiMH battery.
Any number of GCU interrupters can reportedly be synchronised to predetermined "ON/OFF" cycles between 0.1 seconds to 6,000 seconds. With 50 factory preset ranges and 50 user selectable ranges, any variation of switching cycle can be chosen and saved for future use. The units can be programmed to sleep during non survey hours, such as night time, and then reactivate to continue the survey routine.
With a claimed accuracy of 20m/seconds a day the units can reportedly operate for prolonged periods before any re-synchronisation is necessary. With the display switched off up to 150 hours of switching time is possible before batteries require re-charging.
Details available from: BAC Corrosion Control Ltd. Tel: +44 (0) 1952 290321; E-mail: tony.g.uk@bacgroup.com