Pipeline operators must confirm that pipelines and other buried metal structures such as tanks and vessels, are protected cathodically against corrosion.  Measurements are taken at Test Stations, CP Posts (also known as Riser Posts), Isolation Joints and Critical Bonds – where it is important to record ON/OFF pipe-to-soil potentials, native coupon potentials and measurements of bonding or interfering currents.

Although not usually taken as frequently as at the rectifier, manual measurements at CP test points are only spot checks, they only indicate problems well after they have occurred and have no alarm capability.  By contrast, MERLIN Test Post and Bond Monitors provide an immediate indication of CP levels at the important points in the pipeline network.

Manually collecting and analysing field measurements at test posts and critical bonds is labour-intensive and costly.  And (very importantly) they can only be reactive – problems can lie undetected for long periods, during which the pipeline is insufficiently protected.

Alternatively it may simply be that certain measurement points on the pipeline create risks to CP technicians, such as at busy road or rail crossings, or are difficult to access, such as on private land. At these points remote monitoring is very cost-efficient and can improve safety.

In a well maintained CP system all points should be tested periodically but “key posts” should be monitored more intensively, including:

  • Mid-points, end points and low points on impressed current pipelines
  • Points where pipelines cross and may interfere with each other’s protection
  • Bonds, linking pipelines in a common corridor so that they are both protected equally
  • Isolation joints, ensuring that buried (CP-protected) and above-ground (earthed) structures are electrically disconnected from each other
  • Areas where pipelines are affected by electromagnetic fields from power conduits such as buried or overhead high voltage cables
  • Points that are difficult to access, either physically (terrain) or for other reasons, such as on private land where permission is required
  • Points in hazardous areas or situated at busy roadsides
  • Downstream of compressor stations, where elevated gas temperatures may accelerate the corrosion process

Measurements are taken automatically by the MERLIN CP monitor and data is seamlessly sent in a management report to the system HQ where it is displayed and archived in Abriox’s MERLIN CPSM software or online via iCPSM.

Two types of CP monitor are available; the MERLIN CP Monitor which fits inside an M28 test post or bond box and the MERLIN CP Hemi Monitor which fits invisibly within a stand diameter cylindrical riser post. Because they report to a common software platform, different monitor types can be mixed together in the same network.

MERLIN GX CP Monitor (3G/4G)

  • Pipe-to-Soil 1 DC & AC

  • Pipe-to-Soil 2 DC & AC or Instant Off

  • Coupon or Bond Current

  • Native Coupon

Download the datasheet.

US Datasheet

Datasheets require a PDF Reader to view, Adobe Reader can be downloaded for free from www.adobe.com.

Note: Features and specifications are subject to change without prior notice.

MERLIN GX CP Hemi Monitor (3G/4G)

  • Pipe-to-Soil 1 DC & AC

  • Pipe-to-Soil 2 DC & AC or Instant Off

  • Coupon or Bond Current

  • Native Coupon

Download the datasheet.

US Datasheet

Datasheets require a PDF Reader to view, Adobe Reader can be downloaded for free from www.adobe.com.

Note: Features and specifications are subject to change without prior notice.

MERLIN DX CP Monitor (2G/3G)

  • Pipe-to-Soil 1 DC & AC

  • Pipe-to-Soil 2 DC & AC or Instant Off

  • Coupon or Bond Current

  • Native Coupon

Download the datasheet.

Internation Datasheet

Datasheets require a PDF Reader to view, Adobe Reader can be downloaded for free from www.adobe.com.

Note: Features and specifications are subject to change without prior notice.

MERLIN DX CP Hemi Monitor (2G/3G)

  • Pipe-to-Soil 1 DC & AC

  • Pipe-to-Soil 2 DC & AC or Instant Off

  • Coupon or Bond Current

  • Native Coupon

Download the datasheet.

International Datasheet

Datasheets require a PDF Reader to view, Adobe Reader can be downloaded for free from www.adobe.com.

Note: Features and specifications are subject to change without prior notice.

Contact us for more information on how Abriox remote monitoring systems can improve your network management

Please note: Offices are closed weekends and holidays.

Photo Gallery