Our Remote Interface Unit displays sensor measurements for localized monitoring and control. Each RIU has 2 internal relays. The relays can be programmed to send alarms or control a device. For example, they can be used to turn on and off O2 solenoid valves.


12-24VDC,  120mA

Sensor Power

Onboard isolated 24VDC loop power supply


Probe input (optically isolated) (4-20mA, 0-5V, digital on/off, MODBUS RS-485)


8x2 Character, Large Font, LED Backlit

Relay Output

Two SPDT 10 Amp relay-user configurable, LCD/LED Alarm Indicator

Digital Output

MODBUS RTU RS485 communication port, Network addressable


NEMA 4X / IP65, Sealed Cable Grips


-5 °C to +60 °C - Operation/Storage      
-10 °C to +60 °C - Storage

Relative Humidity

5% to 85% RH at up to +40 °C - Operation
5% to 40% RH above +40 °C up to +60 °C - Storage


Up to 3,000 meters ( 10,000 feet ) - Operation/Storage


125mm x 145mm x 75mm   (4.9” x 5.7” x 3”)


457 grams (1 lbs)


Wall mount bracket

More Information and Documentation


A wide-range of probes can be used. Some of the standard options:

  • RIU with OxyGuard Commander galvanic DO/Temp probe (7m cable)
  • RIU with In-Situ optical RDO Pro-X probe (10m cable)
  • RIU with OxyGuard DO probe (7m cable)
  • RIU with OxyGuard precision temperature probe (7m cable)
  • RIU with Sensorex differential pH Sensor (6m cable)
  • RIU with OxyGuard salinity meter (7m cable)
  • RIU with Sensorex differential ORP Sensor (6m cable)
  • RIU with Float switch – stainless steel
  • RIU with Hydrostatic pressure transmitter, 0-250mbar (5m cable)
  • RIU with Sensorex flat surface pH electrode + adapter w/ ground (4m cable)
  • More upon request

RIU Mounting Kit