Limitations
- The presence of closely-spaced reinforcing bar, laps, transverse steel, metal tie, wires or aggregates with magnetic properties can give misleading results.
- The meter has several scales for different bar sizes, therefore the bar diameter must be known if a true indication of cover is to be obtained
- It does not give indication on the quality of concrete cover or the degree of protection afforded to the reinforcement.
- Some search heads are sensitive to changes in temperatures that may be caused by operator’s hand.
- Interference effects will occur in the neighbourhood of metallic structures of significant size such as windows fixings, scaffolding and steel pipes.