RM4210 RMU and Triton Test Station (SAT)


The Bullhorn RM4210 AC/DC Coupon remote monitoring unit (RMU) monitors oil and gas assets in cathodic protection (CP) applications. Combining the RM4210 with the award-winning TRITON Coupon Test Station ensures unparalleled durability, accuracy, and ease of installation. With the combination, you can diagnose AC current issues, monitor AC current, and optimize AC mitigation systems. These devices take accurate AC and DC measurements on three coupons, along with pipe-to-soil measurements using the TRITON’s built-in reference electrode. The RM4210 uploads the measurements via satellite to Bullhorn Web, a web-based asset manager, making it easy for you to view your measurements and determine the best ways to mitigate the risks associated with induced AC corrosion.

Together, the RM4210 and the Triton coupon test station are a turnkey solution for monitoring:

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

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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.

Key Benefits:

  • Form factor – The RM4210 is a fully integrated unit that is mounted on top of the TRITON. 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 – The TRITON coupon test station includes AC and DC coupons and a reference cell in an integrated package that’s simple to install, regardless of where the installation site is located. The RM4210 is also easy to set up – simply connect the pre wired harness to the RMU, affix it to the top of the test station and establish communications using Bullhorn® Tools Mobile. Once the TRITON is in place, the RMU installation take just a few minutes, and you can use Bullhorn Web to apply detailed configurations from the comfort of your office.
  • Accuracy – The RM4210 measure AC and DC voltage with one percent of reading accuracy all the way through the range with auto calibration and autozero for every measurement. For example, a 1 mV measurement will be accurate within ±10 microvolts. The TRITON uses a 1 cm2 AC coupon to represent a relatively small coating holiday. It’s important to use a coupon that approximates the size of the holiday so that small measurement errors are not magnified when the current density is calculated.
  • Detailed Reporting – Quickly identify problem areas and ensure mitigation effectiveness using flexible reports and graphs.

Bullhorn Comparison Chart

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

Bullhorn Comparison Chart

Readings: AC current density, DC current density, AC pipe-to-soil, DC pipe-to-soil, 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
Bullhorn Tools Mobile for IOS
Temperature: -30° C to +70° C
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
AC Coupon :1 cm²
Test Coupon :100 cm²
Native Coupon :100 cm²
Reference Electrode: Stationary Copper / Copper Sulfate
Test point length: 6' 6"
Test point diameter: 3"
Lead length: 30 ft.
RM4210 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)



  • Technical support is provided by NACE-certified professionals via phone and email.
  • Approximately 98 times out of 100, a highly-qualified professional will answer your very first phone call and handle your questions. No call backs; no phone tag.
  • We set you up for success with product training and certification, offered at your place of business or ours.