Abstract: A flat cathodic protection test probe comprises a non-metallic probe body (20) with a mounted metal coupon (18) simulating a large coating holiday on a pipeline, an insulated wire(s) (22) attached to the coupon for an electrical connection to the pipeline, a non-metallic tube (16) filled with a conductive backfill (26), and a narrow and long porous potential sensing strip(s) (40) mounted flush with the coupon exposed surface in the central area of the coupon. The coupon is electrically insulated from the conductive backfill by a non-metallic coating (38) and an epoxy compound for electrical insulation (42). To determine if the pipeline is fully cathodically protected, the flat cathodic protection probe is buried next to the pipeline and interconnected by the insulated wire(s) with the pipeline. The potentials taken on the probe will not include a substantial voltage drop in soil and will not be adversely affected by shielding of the coupon by a reference electrode or its access tube to invalidate the reading.

Abstract: Disclosed is a novel electrochemical probe and technique to monitor biofilm activity before the biofilm has been permanently established and microbiologically influenced corrosion (MIC) initiated. This probe includes two sets of metal electrodes isolated from each other. A power source is used to apply a potential difference of between 50 and 500 mV on the two sets of electrodes to activate the probe. Programmed timing, measuring and switching equipment and a data recording device monitors the biofilm-caused depolarization effects on the electrode sets by measuring an increase of DC current produced by the applied potential difference. The equipment also monitors DC current generated between the electrodes after removing the power source and records the AC resistance between the electrodes indicating mostly the resistance of the biofilm covering the electrodes.

Abstract: Disclosed is a novel electrochemical probe and technique to monitor biofilm activity before the biofilm has been permanently established and microbiologically influenced corrosion (MIC) initiated. This probe includes two sets of metal electrodes isolated from each other. A power source is used to apply a potential difference of between 50 and 500 mV on the two sets of electrodes to activate the probe. Programmed timing, measuring and switching equipment and a data recording device monitors the biofilm-caused depolarization effects on the electrode sets by measuring an increase of DC current produced by the applied potential difference. The equipment also monitors DC current generated between the electrodes after removing the power source and records the AC resistance between the electrodes indicating mostly the resistance of the biofilm covering the electrodes.