Covermeter survey – concrete cover to reinforcement

Concrete cover to the steel reinforcement in a structure or building ensures that the steel is maintained at a sufficient depth into the concrete to be well away from the effects of carbonation or chloride ingress.

Electromagnetic devices, also known as "covermeters", are used for the non-destructive measurement of steel reinforcement concrete cover in structures. The presence of reinforcement in concrete can be detected by the influence that the reinforcement has on the electromagnetic field induced by the covermeter.

We also use the Profometer PM-650, an advanced covermeter for the precise and non-destructive measurement of concrete cover and rebar diameters and the detection of rebar locations using the eddy current principle with pulse induction as the measuring method.

Covermeter surveys form part of most concrete condition surveys of buildings or structures. Covermeter surveys can also locate main and secondary reinforcement to determine bar sizes, bar spacing, to determine minimum cover and cover variability across an element.

The position of reinforcing steel and pre-stressing strands is sometimes also required to avoid them during core sampling or other tests which may be affected by their presence (concrete resistivity).

The use of covermeters is described in British Standard 1881: 204: 1988.