Electro-Optic Interstitial Sensor (EIS)

The electro-optic interstitial sensor (EIS) may be used with all EVO™ Series fuel management system ATGs. 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.



  • 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.



  • UL listed.
  • ATEX approved.
  • IECEx approved.


For dry tank interstitial monitoring.


Each EIS comes with 25′ 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.

Order Info

Model Description
FMP-EIS Electro-optic interstitial sensor(EVO™ 550 and EVO™ 5000)
FMP-EIS-U Electro-optic interstitial sensor (EVO 200 & EVO 400)
TSP-K12 Interstitial sensor riser cap kit for 2″ riser pipes
  • Note: Thie EIS and the EIS-U communicates with the ATG using 3 wires and 2 wires, respectively.