Why Ethanol Sumps Need a Sensor That Isn't Fooled by Rain, Grease, or Old Residue

Ask anyone who manages a tank farm or blending terminal what keeps them up at night, and "nuisance alarms" will come up almost as often as "actual leaks." A sensor that cries wolf every time it rains, or every time a little residual oil film sits in a sump, eventually gets ignored. And a sensor that gets ignored isn't protecting anything. That's the exact problem Naftosense set out to solve with the FLD-xRTD-PS, a self-powered acquisition module built for facilities that need to catch ethanol and hydrocarbon leaks without drowning operators in false positives.

Sumps are the low points built into tank farms, blending terminals, and loading racks specifically to catch anything that leaks — a basin where drips and spills collect instead of spreading into the surrounding soil. For most fuels, that containment strategy works well because the fuel floats and pools where it's easy to spot. Ethanol breaks that assumption. It's fully miscible with water, so instead of forming a visible layer, it dissolves right into whatever water is already sitting in the sump — condensation, rain, cleaning runoff — and disappears from view. That's precisely the blind spot the FLD-xRTD-PS and its sensing probe are built to close.

Built for the Field, Not Just the Lab

The FLD-xRTD-PS is designed to live outdoors, in the kind of conditions that would put most electronics out of commission: freezing winters, scorching summers, condensation, humidity, and years of exposure without anyone opening the enclosure. It pairs with a reusable, fully passive sensing probe from Naftosense that's installed in sumps, containment areas, and other low points where leaks tend to collect. Because the probe is passive and reusable, facilities aren't stuck replacing sensing elements every time there's a minor event.

What sets this module apart is the intelligence built into how it reads the probe. Rather than treating any conductive change as an alarm, the module runs advanced measurement and data-treatment algorithms that learn to tell the difference between a genuine leak and background interference like motor oil residue, grease, or the ghost of a leak that happened months ago. That distinction matters enormously in real-world operations, where sumps rarely stay pristine.

Speaks the Language Your Instruments Already Know

One of the more practical touches is how the FLD-xRTD-PS reports its status. Instead of requiring a proprietary output that only works with Naftosense hardware, it emulates a standard Pt100 RTD signal. That means it plugs directly into the temperature transmitters and monitoring systems facilities already have on hand, and it can be tested with something as simple as a multimeter. Engineers don't need specialized diagnostic equipment to confirm the unit is working correctly, and integrators can pair it with practically any third-party wireless transmitter on the market.

The resistance readings themselves are easy to interpret on sight: roughly 100 ohms means everything is normal, a jump into the 151-300 ohm range signals a leak (with 32 graduated steps to indicate severity), and anything above 1 kOhm tells you the battery has run out and the unit has shut down. There's even a distinct reading for a broken sensor string versus a hardware fault, so troubleshooting doesn't turn into guesswork.

No Wiring, No Maintenance Visits, No Surprises

Because the field box runs on an internal lithium thionyl chloride battery rather than external power, installation is simpler and there's no cable run to maintain. Naftosense rates the expected service life at more than a decade, even in extreme cold, and backs the unit with a 10-year warranty. It's IP67/NEMA4X rated, so it can handle outdoor exposure and even direct burial immersion, and it's certified for hazardous locations under ATEX, IECEx, and North American Class I, Division 1 / Zone 0 standards, in either an F4 model (rated to 140°F) or a T3 model (rated to 176°F).

For refineries, distilleries, tank farms, and fuel retail sites juggling ethanol blends, oil-on-water conditions, or both, the FLD-xRTD-PS offers a way to get reliable, low-maintenance leak detection without adding another point of failure to the facility's infrastructure.