Bullhorn Model RM4210 Coupon Test Station Remote Monitor by American Innovations

Satellite Controlled, AC/DC Coupon Remote Monitoring Unit for Cathodic Protection Applications


Mounted on a test station, the RM4210 measures induced AC voltage, AC current, and associated current density. It also measures DC voltage, DC current, instant-off and current flowing through a decoupling device. These measurements are automatically uploaded to Bullhorn Web via satellite communication. Once uploaded, you can easily monitor them and use them to design andoptimize your AC mitigation systems.

Located at coupon test stations, it measures the induced AC voltage, AC current, and associated current density that can be present on pipelines that are co-located with high-voltage AC power lines. The RM4210 uploads these measurements via satellite to Bullhorn Web, a web-based asset manager, so you can diagnose AC current issues, monitor them over time, and optimize your AC corrosion mitigation systems.

Remote monitoring for:

  • AC coupons
  • AC and DC current density
  • AC and DC pipe-to-soil
  • Native pipe-to-soil
  • PCR AC current

Key Benefits

  • Form factor – The RM4210 is a fully integrated unit that can be mounted on any AC/DC coupon test station. All components, including the antenna, are internal so it is easier to transport and install as well as it’s less likely to incur damage that will require a future repair visit.
  • Ease of installation – Installing the RM4210 normally takes just a few minutes. Simply connect the pigtail to the test-points, affix it to the top of the test station, and establish communications using Bullhorn® Tools Mobile via Bluetooth. You can then use the Bullhorn Web asset manager to apply detailed configurations from the comfort of your office.
  • Accuracy – The RM4210 measures with one percent of reading accuracy all the way through the range with auto-calibration and auto-zero for every measurement. For example, a 1 mV measurement will be accurate within ±10 microvolts. Accuracy is especially critical when using a small AC coupon, as small errors are magnified when the current density is calculated.
  • Detailed Reporting – Quickly identify problem areas and ensure mitigation effectiveness using flexible reports and graphs.

Feature Benefit
Test station cap form factor Easy to install and maintain, simply latch and unlatch as needed. No separate antenna to mount.
One percent of reading accuracy Extremely accurate current and voltage measurements
Long lasting battery Reduced maintenance costs and visits to the unit
Alerts when current density exceeds thresholds Avoid incidents and prevent corrosion due to AC current
Measurement frequency up to every quarter hour Easily troubleshoot issues and identify cause of AC current
Customizable AC monitoring graphs and reports Show effectiveness of mitigation and easily drill down on trouble areas
10 MΩ impedance Improved pipe-to-soil accuracy where just a few mA can be the difference between being in compliance and not
Flexible reporting Easily generate reports and hone in on trouble areas quickly
Mobile configuration and setup application No need to carry a laptop into the field to set a unit up, do it right from your mobile phone
Queued two-way communication Poll, reconfigure, modify reporting schedules, set alarm thresholds and update firmware over-the-air. Communication to the RMU is queued in Bullhorn Web and is sent the next time the unit wakes up to transmit
Sends alarms based on specific events (e.g. reading out of range, power loss, etc.) Receive unlimited notifications via text message, email, and voice
Configurable over-the-air via Bullhorn Web
  • Configure remotely from the office
  • Update firmware from the office
  • Set up current density alarms remotely
Bullhorn Web system communicates unit status by email, text, or Web notifications
  • Eliminate remote site visits with equipment status notifications
  • Get on-the-go access via smartphone
More than 6.6 kV built-in surge protection per IEC 61000-4-5 specifications Increase product reliability with immunity to lightning and other surges



AC current density, DC current density, AC pipe-to-soil, DC pipe-to-soil, native pipe-to-soil, PCR AC current drain, instant off
DC voltage: +/- 100 V max
AC voltage: 0-100 V max
AC current: 0-200 mA max
Channel-to-channel isolation: > 200 V
Input impedance: 10 MΩ
Instant Off
Default IR drop edge delay: 200ms


Bullhorn Tools Mobile via Bluetooth Low Energy


SkyWave - Inmarsat satellite


Software Interface
Bullhorn Web
Mobile configuration and troubleshooting app


Power Supply
Internal field-replaceable primary and secondary batteries
Battery life is 3-7 years when recording measurements hourly or daily with weekly transmissions
Additional DC input voltage: 10-24 V DC


Single integrated unit fits atop standard 3" test post
With a test point adapter: 6.06” W, 8.22” H, 17” circumference


Data Integrity
Data stored in non-volatile (EEPROM) memory
Queued two-way communication (communication to the RMU is queued in Bullhorn Web and is sent the next time the unit wakes up to transmit)


Temperature: -30° C to +70° C


Safety and Compliance
Certification mark: TUV
Tested safety standards:
  • CAN/CSA C22.2 No. 61010-1-2012
  • CAN/CSA C22.2 No. 61010-2-030:2012
  • UL61010-1:2012
  • UL61010-2-030:2012