DIN 50925:1992-10

1 Scope and field of application
2 Concepts
      2.1 Cell current
      2.2 Coupon
      2.3 Impressed-current electrode
             2.3.1 Impressed-current anode
             2.3.2 Impressed-current cathode
      2.4 Intensive measurement
      2.5 Intensive measurement method
      2.6 IR*)-free potential
      2.7 Structure/electrolyte potential
      2.8 Potential gradients
3 Measurement of structure/electrolyte potentials
      3.1 Objective of potential measurement
      3.2 Sources of error in potential measurement
             3.2.1 Protection current
             3.2.2 Equalizing current
             3.2.3 Cell current
             3.2.4 Stray current
      3.3 Methods of measuring IR-free structure/soil
             potentials
             3.3.1 Measurement of instantaneous-off
                      potentials (instantaneous-off potential
                      method)
             3.3.2 Intensive measurement methodting
                      currents
                      3.3.2.1 Symmetrical potential
                                 gradients
                      3.3.2.2 Asymmetrical potential
                                 gradients
                      3.3.2.3 Evaluation of intensive
                                 measurement data
                      3.3.2.4 Intensive measurement
                                 method will stray current
                                 interference
             3.3.3 Potential measurement with coupons
4 Action to be taken in the case of inadequate cathodic
      protection
5 Advice on monitoring procedures
6 Assessment of corrosion protection in the presence of
      strong alternating currents
Standards and other documents referred to
Explanatory notes

This standard is included in DIN Handbook 219. Deals with the verification of the effectiveness of the cathodic protection of buried structures as specified in DIN 30676, such verification involving checking whether the protection potential criterion is fulfilled. Depending on the type of structure protected, verification may refer to discrete surface regions; the intervals at which checks are made shall be in accordance with the monitoring requirements specified in the relevant code of practice.