What must be avoided to prevent interference with corrosion testing?

To prevent interference with corrosion testing, avoiding contact with bare fingers when handling coupons is crucial. Oils, salts, and moisture on human skin can contaminate the test coupons. These substances can significantly alter the results of corrosion tests by introducing additional variables that are not part of the actual corrosive environment being assessed.

For accurate measurements, it is important to ensure the surface of the coupons remains uncontaminated and reflects only the conditions under which they are being tested. By not touching the coupons with bare fingers, the integrity of the corrosion readings is maintained, allowing for a more reliable analysis of the material's resistance to corrosion.