The push toward sustainability is transforming the commercial transport and plant machinery sectors. Fleet managers and original equipment manufacturers (OEMs) are increasingly turning to low-carbon fuel alternatives to hit strict environmental targets.
Whether transitioning to biodiesel blends (like B20 or B100), Hydrotreated Vegetable Oil (HVO), or managing standard forecourt petrol and E10 blends, the environmental benefits are clear. However, transitioning to alternative fuels isn’t just a matter of changing your fuel supplier. It fundamentally alters the chemical environment inside your tanks.
Without the right fuel level monitoring hardware, modern alternative fuels can silently degrade internal components, leading to premature sensor failure, skewed telemetry data, and unexpected vehicle downtime. Understanding how alternative fuel compositions affect sensor longevity (and why choosing compatible materials matters) is essential for smooth operational transitions.
The Chemical Challenge of Biofuels
Traditional fossil diesel and petrol are highly predictable hydrocarbon fluids. Industrial fuel sensors have been designed around their properties for decades. Biofuels, on the other hand, introduce entirely different chemical and physical properties into the tank ecosystem:
1. Increased Solvency and Material Degradation
Biodiesel acts as a mild solvent. If a fuel level sensor relies on standard rubber gaskets, certain plastics, or low-grade polymers, biodiesel can aggressively dissolve or swell these materials over time. Once a seal degrades, fuel enters the sensor housing, shorting out internal electronics.
2. High Hygroscopicity (Water Attraction)
Biofuels (especially ethanol-blended petrol (E10) and biodiesel) are highly hygroscopic, meaning they pull moisture directly from the air. This elevated water content creates two primary problems for inferior fuel sensors:
- Corrosion: Constant exposure to moisture accelerates the oxidation of subpar metals.
- Microbial Growth: Water-in-fuel contamination creates a breeding ground for fuel bugs (bacteria and fungi). This biological sludge can coat, clog, or corrode traditional mechanical float switches.
3. Altered Dielectric Properties
Electronic sensors, particularly capacitance level sensors, measure fuel levels by tracking changes in the electrical properties (dielectric constant) inside the tank. Biodiesel and ethanol have significantly higher dielectric constants than standard fossil fuels. If a sensor isn’t specifically engineered to handle or automatically calibrate for these shifts, your fleet telematics will receive highly inaccurate volume readings.
Why Material Selection is Your Best Defense
To survive long-term immersion in modern biofuels, fuel level sensors must be constructed from chemically inert, high-specification materials. When evaluating sensors for an alternative-fuel-powered fleet or custom OEM tank build, three main material categories deserve close attention:
|
Component Type |
Inferior/Standard Materials (Risk of Failure) |
Biofuel-Compatible Materials (Best Practice) |
|
Seals & Gaskets |
Nitrile rubber, Neoprene (Swells, degrades, and leaks) |
Viton™ (FKM) or Fluorosilicone (Maintains structural integrity) |
|
Sensor Probes |
Low-grade plastics or thin anodised aluminum |
Stainless Steel (316L) or specialised engineering polymers |
|
Internal Mechanics |
Moving mechanical floats (Prone to sticking due to bio-sludge) |
Solid-state electronic designs (No moving parts to clog or jam) |
Selecting the Right Sensor Technology for Modern Fuel Tanks
Beyond the raw materials, the specific sensor technology chosen impacts how successfully alternative fuels can be managed.
Capacitance Sensors
Advanced capacitance sensors, such as the Rochester Sensors T/LL130 series, are highly effective for alternative fuels because they feature a solid-state design with no moving parts to clog or stick. However, because biofuels change the dielectric baseline, selecting a variant engineered for multi-fuel compatibility or utilising a model that allows for easy field recalibration ensures that the readings remain pinpoint-accurate.
Hydrostatic Sensors
Hydrostatic liquid sensors measure liquid level based on the weight of the fuel column above them. Because HVO and biodiesel have slightly different densities from standard EN590 diesel, utilising smart hydrostatic sensors allows operators to account for specific liquid densities, delivering highly accurate, continuous level data without being affected by changes in electrical properties.
Future-Proofing Fleet Infrastructure
Adopting biofuels is a major step toward a cleaner operational footprint, but hardware readiness must match environmental ambitions. Retrofitting infrastructure or specifying new builds with multi-fuel-compatible sensors ensures that operations remain resilient, no matter how fuel compositions evolve in the coming years.
Before making the switch to higher biofuel blends, audit existing fuel assets. Investing in robust, solid-state sensors built with high-grade stainless steel and Viton™ seals protects machinery, secures telematics accuracy, and prevents the costly disruption of premature sensor failure.
For more information on fuel level sensors, get in touch with Rochester Sensors on 01926 466700.