Bullhorn RM4211 and RM4251 Remote Monitors
Bullhorn RMUs RM4211 and RM4251 accurately monitor critical oil and gas assets in various cathodic protection (CP) applications. These include coupon test stations, bonds, decouplers, and solar-powered rectifiers.
Why Choose Bullhorn RM4211 or RM4251?
The RM4211 and RM4251 accurately monitor critical oil and gas assets in various cathodic protection (CP) applications. These include coupon test stations, bonds, decouplers, and solar-powered rectifiers.
The difference between these two units is the method of communication. The RM4211 uses satellite communication, while the RM4251 uses cellular communication.
They both capture a range of measurements:
- AC/DC Pipe-to-Soil
- Rectifier Volts and Amps
- and more
A long-lasting battery combined with satellite or cellular connectivity means you can access reliable, near-instantaneous communication.
Bullhorn RM4211 and RM4251 Features and Benefits:
Versatility – The RM4211 (satellite) and RM4251 (cellular) facilitate remote monitoring across many applications including coupon test stations, bonds, solar-powered rectifiers, decouplers and more. Get IR-free instant off coupon readings for annual interrupted surveys. Mount them on any 3” riser or rectifier. Measure up to 100 V on a rectifier or low voltage on a test point application. Ensure Cathodic Protection (CP) effectiveness by recognizing asset failure. Program alarm criteria and alert notifications using Bullhorn Web
Power – No power, no boat, no helicopter, no problem! Battery life (of up to 10 years long) with satellite or LTE Cat M cellular connectivity, make these RMUs ideal in remote locations like swamps, mountains, and private land where cell signals and power are unavailable.
Efficient & Cost-Efffective – Bullhorn remote monitors survive the harshest conditions with built-in surge protection. For enhanced safety against surge events, you can add a high-energy surge arrester or Advanced SurgeProtect Kit .
Input measurement level +/- V DC | 0-100 V AC
Input Impedance 10 MΩ
Channel-to-channel isolation: >200V
Readings: Three analog measurements; any combination of AC & DC
pipe-to-soil, On and Off Potentials, Rectifier Volts and Amps
(with external shunt), and Bond Negatives. Instant off through
Coupon. One percent reading accuracy through the range with
auto-calibration and auto-zero for every measurement. 1 mV measurement will be accurate within ±10 microvolts.
IR drop edge delay: Configurable IR drop edge delay: 200 ms default
Bullhorn Tools via Bluetooth low energy
Bullhorn Tools for iOS and Android
Battery or Optional Power Supply
Internal, field-replaceable primary and secondary batteries
More than 9-year replacement when recording weekly
measurements with weekly transmissions
Additional DC input voltage: 10-24 V DC or solar panel
Ø6.06″ x 3.96″ H (8.22″ H with test station adapter)
Data stored in nonvolatile (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 +60° C
Safety and Compliance
Certification mark: Tested Safety Standards:
Tested Safety Standards:
TUV CAN/CSA C22.2 No. 61010-1-2012
CAN/CSA C22.2 No. 61010-2-030:2012