Limitations
- The main limitation of this test method is that conclusive remarks cannot drawn solely on the results obtained, and the other supporting data like chloride content, depth of carbonation, rate of corrosion results, and environmental exposure are required.
- The spacing between each reading on the surface of the concrete member where the test is performed is to be consistent and too wide a spacing may not enable detection of localised corrosion activity
- Readings are weather-sensitive, it only works well with concrete which is uniformly moist and close to saturation.
- The method does NOT provide information about the rate of corrosion.
- The technique only reflects the potentials of the steel nearest the surface.
- Investigation cannot be carried out on key structural sections which direct surface access is not possible e.g. bridge half-joints.