Electro-Optic Interstitial


Electro-Optic Interstitial

Utilizing electro-optic technology, and made of chemically-resistant polysulfone plastic, the EIS may be installed in sumps, double wall tanks, or other locations where the presence of liquid indicates a leak has occurred.

Sensors EVO Highlight Intro.psd

Electro-Optic Interstitial Sensor

  • Highly accurate electro-optic technology and closed
    output circuit ensures that leaks are detected.
  • Chemical-resistant materials.
  • Can be installed in fiberglass or steel double wall tanks.
  • Utilizes light-emitting diodes and prisms to indicate if a
    leak has occurred.
  • Each EIS comes with 25' (7.6 m) of oil-resistant cable. For fiberglass tanks, the EIS is pulled into the interstitial space using a “fish” string or wire. For steel interstitial tanks, the EIS is lowered directly to the bottom of the interstitial space through a 2" NPT fitting provided for that purpose on the tank. Optional installation kits are available which include a riser cap and other parts required to complete installation.

No matter what the monitoring application is, Franklin Fueling Systems offers a sensor solution tailored to the specific requirements of each application.

Let us help you choose the right sensor for your application.

Sensor Selection Wide Short.psd


  • For dry tank interstitial monitoring.


  • UL listed.
  • ATEX approved.
  • IECEx approved.
Model Number Description
FMP-EIS-U Electro-optic interstitial sensor (EVO™ 200, EVO™ 400, EVO™ 600 and EVO™ 6000)
FMP-EIS Electro-optic interstitial sensor (EVO™ 550, EVO™ 5000, EVO™ 600 & EVO™ 6000)
TSP-KI2 Interstitial sensor riser cap kit for 2" riser pipes
TSP-KW4 Interstitial sensor riser cap kit for 4" riser pipes
  • Note: The FMP-EIS wires to the 3 wire sensor module and the FMP-EIS-U wires to the probe module.