Removal and examination of coupons

Measure the pH of water on the external surfaces of the coupons. Compare with the pH of the bulk water sample. 

Photograph the overall rack assembly prior to disassembly. Photograph all points of interest showing significant corrosion phenomena, including any corrosion of the edges. 

Remove the individual coupons from the rack assembly. 

Photograph the front and the back of each individual coupon. A small card with a note of the material, immersion time and identity number, photographed together with the coupon surface, would be very useful. Count the number of pits. 

Provide written observations of specific corrosion phenomena for individual coupons, including ease of removal (ease of separation of crevice/bimetallic coupons), amount and type of loose deposits, staining, discoloration, pitting, tenacious or loose oxides, raised embedded particles felt with a gloved finger, etc. 

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