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 cathodic protection 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 Station 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.

Further consideration should be made to monitor the effect of induced AC on the pipeline causing extremely aggressive ‘AC corrosion’. This can cause major problems in a very short time, often sooner than the frequency of manual measurements. Combine this with a very real danger if the AC is too high means monitoring the effect of stray AC currents is critical.

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 causing dangerous stray currents

  • 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.

Abriox has a number of RMU’s for these applications; the MERLIN CP Monitor which fits inside an M28 test post and the MERLIN CP Hemi Monitor which fits invisibly within a stand diameter cylindrical riser post.  Additionally, we have an AC Monitor and Bond Monitor which will fit in cylindrical riser posts and bond boxes respectively.

Because all Abriox MERLIN RMU’s report to a common software platform, different monitor types can be mixed together in the same network.

MERLIN Test Station and Bond Monitors

MERLIN6 CP Monitor - International Use

  • Daily CP Level Check (Hourly Option for Problem Solving)

  • ON / OFF / Native Potentials

  • Coupon Current Monitoring

  • DC and AC Monitoring

  • 5 Year Battery Life

  • 4G/3G (US Networks)

    4G/2G (UK Networks)

  • Weekly Report Gives Min, Max and Average of All Channels

  • Custom High/Low Alert Thresholds

  • Wide Operational Temperatures

  • Typically Installed Inside Test Post

View the product info sheet.

View product info sheets

Product info sheets 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.

MERLIN6 Bond Monitor - US Only

  • Daily Measurements (Hourly Option for Problem Solving)

  • Isolated DC and AC Channel Monitoring

  • 5 Year Battery Life

  • 4G/3G (US Networks)

  • Weekly Report Gives Min, Max and Average of All Channels

  • Custom High/Low Alert Thresholds

  • Wide Operational Temperatures

  • Typically Installed Inside Bond Box

View the product info sheet.

View product info sheets

Product info sheets 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.

MERLIN6 AC Monitor - US Only

  • Daily AC Standing Voltage and Current Flow to Coupon (Hourly Option for Problem Solving)

  • Isolated DC and AC Monitoring

  • 5 Year Battery Life

  • 4G/3G (US Networks)

  • Weekly Report Gives Min, Max and Average of All Channels

  • Custom High/Low Alert Thresholds

  • Wide Operational Temperatures

  • Typically Installed Inside a Riser Post

View the product info sheet.

View product info sheets

Product info sheets 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.

MERLIN6 CP Hemi Monitor - US Only

  • Daily CP Level Check (Hourly Option for Problem Solving)

  • ON / OFF / Native Potentials

  • Coupon Current Monitoring

  • DC & AC Monitoring

  • 5 Year Battery Life

  • 4G/3G (US Networks)

  • Weekly Report Gives Min, Max and Average of All Channels

  • Custom High/Low Alert Thresholds

  • Wide Operational Temperatures

  • Typically Installed Inside a Riser Post

View the product info sheet.

View product info sheets

Product info sheets 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.