US 6,982,563 B2
Monitoring of corrosion induced loss of material by means of a plurality of electrical resistance measurements (field signature method, electrical resistance tomography)
Brian Hands, Cumbria (United Kingdom)
Assigned to British Nuclear Fuels PLC, Seascale (United Kingdom)
Appl. No. 10/416,423
PCT Filed Nov. 06, 2001, PCT No. PCT/GB01/04889
§ 371(c)(1), (2), (4) Date Sep. 02, 2003,
PCT Pub. No. WO02/39102, PCT Pub. Date May 16, 2002.
Claims priority of application No. 0027398 (GB), filed on Nov. 09, 2000; and application No. 0027638 (GB), filed on Nov. 11, 2000.
Prior Publication US 2004/0061510 A1, Apr. 01, 2004
Int. Cl. G01R 27/08 (2006.01); G01N 17/00 (2006.01)
U.S. Cl. 324—700 18 Claims
OG exemplary drawing
 
1. A method of investigating loss of material from a location, the method comprising:
i) defining the actual location to be investigated;
ii) providing two or more electrical contacts in contact with the actual location;
iii) measuring the voltage between the two or more electrical contacts in contact with the location at a first time and at a second time, a current being passed through the location at the time of the voltage measurements, the voltage measurements having a relationship to the loss of material;
iv) generating a model of the location configuration, the model including two or more points on that model of the location, modelling the values generated for the voltages which would be measured between the two or more points with a current applied to the model of the location at the first time;
v) generating a further model of the location configuration at least at the second time, the further model including a change in location configuration between the first time and the second time to model loss of material from the location, the further model including two or more points on that further model of the location, modelling the values generated for the voltages which would be measured between the two or more points with a current applied to the further model of the location at the second time; and
vi) comparing the model voltage differences with the voltage differences for the location at the second time, an alternative model of the location configuration being generated if the comparison is not acceptable, the model of the location configuration being equated to the location configuration if the comparison is acceptable;
the differences between the location configuration of the first time and the acceptable comparison for the at least second time indicating the material loss from the actual location between the first and second times.