Liquid Level – Resistive (RL1/RL2)

3-in-1 or 5-in-1 Wireless Tank Level Monitoring Solution.

  • RL1: 3-in-1 process monitoring product, interface & temperature
  • RL2: 5-in-1 process monitoring – RL1+ 2x discrete inputs
  • High accuracy and reliability using field-proven reed switch design
  • Flex sensor option: 8-38 ft lengths
  • Rigid sensor option: 2-17 ft lengths
  • Sensor supports wide temp. range -40 ˚C to 120 ˚C / -40 ˚F to 248 ˚F
  • US Patent 8,763,455 B1
  • No wiring quick connect adapter
  • Over 7-year battery life
  • Class I, Division 1 (Zone 0), intrinsically safe
  • 900 MHz: Up to 7500 ft (2.3 km)
  • 2.4 GHz: Up to 4.3 miles (7 km)
  • Secure AES encryption


The OleumTech® RL1 Resistive Liquid Level Transmitter is capable of monitoring product, interface, and temperature, making it ideal for industrial tank level applications.  The level output in inches or cm.  Additional data such as volume and tank full % can be reported as well based on user preference.  The RL2 offers 2x discrete inputs, providing 5-in-1 capability.


The Resistive Transmitter mates to either OleumTech Flex or Rigid Resistive Sensor that is sold separately.  The flex sensor is available in 8 to 38 ft (2.4 to 11.6 m) lengths while the rigid sensor is offered in 2 to 17 ft (0.6 to 5.2 m) lengths.  Both versions are available in 1 ft (0.3 m) increments and can be ordered with a single or dual-float configuration option.


The RL1 and RL2 Transmitters rely on power from a replaceable battery. The system is engineered to achieve maximum battery life, providing +7 years of life from a single battery.


Designed for use in Class I, Division 1 (Zone 0) hazardous locations.  These Transmitters are intrinsically safe, meaning they cannot a cause a spark and can be serviced without being removed from a process.


The OTC Sensor Network is managed using the BreeZ Software by OleumTech, provided free of charge. The High Level Switch Transmitter can be configured using the push button interface or BreeZ Software.


The Resistive Transmitter is one of many Wireless Transmitters that communicates with an OleumTech Wireless Gateway within its network, creating a highly scalable network, accommodating virtually any level or I/O requirement.