US 12,235,205 B1
Methods and systems for coupon-based cathodic protection measurements
Calvin C. Chapman, IV, Kerrville, TX (US); and Samuel F. Williams, San Antonio, TX (US)
Assigned to CHAPMAN ENGINEERING, INC., Boerne, TX (US)
Filed by Chapman Engineering, Inc., Boerne, TX (US)
Filed on Mar. 1, 2024, as Appl. No. 18/593,754.
Claims priority of provisional application 63/624,396, filed on Jan. 24, 2024.
Int. Cl. G01N 17/02 (2006.01); C23F 13/22 (2006.01); G01N 17/04 (2006.01)
CPC G01N 17/02 (2013.01) [C23F 13/22 (2013.01); G01N 17/043 (2013.01)] 30 Claims
OG exemplary drawing
 
1. A method of measuring cathodic protection of a metallic structure using a plurality of coupons, the method comprising:
electrically coupling a first coupon to the metallic structure, the first coupon comprising a first material;
electrically coupling a second coupon to the metallic structure, the second coupon comprising a second material;
applying a first cathodic protection current to the metallic structure;
interrupting the application of the first cathodic protection current;
measuring a first voltage of the first coupon with respect to a reference cell, while the application of the first cathodic protection current is interrupted;
measuring a second voltage of the second coupon with respect to the reference cell while the application of the first cathodic protection current is interrupted;
electrically coupling the first coupon to the second coupon;
measuring a third voltage between the electrically coupled first and second coupons and the metallic structure while the application of the first cathodic protection current is interrupted with respect to the reference cell; and
determining whether a degree of cathodic protection applied to the metallic structure is sufficient based on the measured third voltage.