Hardwired Resistive Level Sensors (RL3/RL4)

Precise Liquid Level Monitoring Solution (Modbus/LevelMaster).

  • 3-in-1 process monitoring: Product, interface, temperature
  • Precise and reliable measuring capabilities using resistive technology
  • Flex sensor option: 8-38 ft lengths
  • Rigid sensor option: 2-17 ft lengths
  • Modbus (RL3) or LevelMaster (RL4) option
  • US Patent 8,763,455 B1
  • API 18.2 Compliant – (Rigid Sensor with 1/4″ resolution and 1/8″ accuracy only)
  • Sensor supports wide temp. range -40 ˚C to 120 ˚C / -40 ˚F to 248 ˚F
  • Low power consumption
  • 6-12 Vdc Power Input
  • Supports up to 16 sensors multi-dropped
  • Class I, Division 1 (Zone 0), intrinsically safe


The OleumTech® H-Series Resistive Level Sensor is a high precision liquid level instrument capable of monitoring product,
interface, and temperature, making it ideal for industrial tank level applications. The Sensor accepts 12 VDC input and up to
sixteen Sensors can be multi-dropped. Additional data such as volume and tank full % can be calculated as well.


Designed for use in Class I, Division 1 (Zone 0) hazardous locations. The Resistive Level Sensor is intrinsically safe, meaning it cannot a cause a spark and can be serviced without being removed from a process.


OleumTech offers Flex PTFE and Rigid 316SS Sensor that support either Modbus (RL3) or LevelMaster ASCII (RL4) protocol. 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 single or dual-floats.  Both Sensor types offer quick connect adapter that require no Sensor wiring reducing hassle and eliminating wiring errors.


The Resistive Liquid Level Sensor is easily configured using the H-Series Configuration Software for PC.