Diesel power generator with fuel tank

What are the types of fuel level sensors that can be used in back-up power generators?
Point level and continuous level measurement using a float, radar, and capacitive technologies.

Monitoring “mission critical” fuel levels in back-up generator systems needs to be reliable. Gensets are particularly sensitive to failure issues. Emergency generators are often dormant for long periods of time. They need to be available for emergency action when external power is cut off and immediate. Absolute reliability is needed to keep cell phone towers, businesses, and especially hospitals across the world functioning without interruption. Also, a genset may be the only source of power to keep remote applications operating when it is hard to reach for maintenance staff.

The fuel level sensors used for these critical operations have to function regardless of variations to fuel type or quality. It could be something as simple as refilling a diesel tank with non-standard fluid, or a change to a new fuel brand. For that reason, float switches or float sensors ignore these variances as long as the specific gravity of the liquid doesn’t drastically change. Radar will also reliably sense any fuel ignoring vapors and changes in fuel. The capacitive level sensor is a point level sensor that can be used for safety as alarm indication for too low or too high fuel levels.


Gems Sensors has the following solutions for fuel level sensors to meet a variety of needs in back-up generators:



xm-700 / XT-700 continuous float fuel level sensor
Continuous float fuel level sensor

XM-XT 700-Series Continuous Level Transmitter combine the durability of stainless steel or brass construction with a lightweight, compact design for restricted spaces. XM-XT 700 are ideal for tanks less than 2 feet.

XM-700 / XT-700 >


Ultrasonic continuous fuel level sensor



Ultrasonic Continuous fuel level sensor

UCL-510 Ultrasonic Continuous Level Transmitter is a non-contact level sensor with no-moving parts built for general purpose small tank applications and offers switch, controller, and transmitter capabilities in one multi-function transmitter. It is suited for corrosive and dirty applications, is virtually maintenance free, and reduces tank system hardware.

UCL-510 >

 Point level Float fuel level sensor



Point level Float fuel level sensor

LS-700 Series Multi-Point Level Switch is a compact unit that features the rugged durability of stainless steel or brass construction in a lightweight package. It is ideal for restricted spaces, including tanks less than 4 feet (1.22 m).

LS-700 >

 Ultrasonic point level fuel level sensor



Ultrasonic Point level fuel level sensor

The XLS-1 Ultrasonic Level Sensor is Gems' rugged alternative to reed switch level sensors. They are compatible with water, water-based, and hydrocarbon-based liquids. The XLS-1 is an ideal solution for sensing liquid levels in generators, water tanks, radiators, and other harsh industrial applications.

XLS-1 >

point level float fuel level sensor

Horizontal Point level Float fuel level sensor

Built for durability, our LS-7 Series switches utilize stainless steel or zinc bodies. Ideal for any small tank or vessel destined for a rugged environment.


LS-7 >

Radar continuous fuel level sensor

Radar continuous fuel level sensor          

Available in a compact design constructed from chemically inert PVDF material, the RLI Series Non-Contact Radar Sensor features models that work in tanks up to 49.21’ (15 m) deep! Its simplified programming and setup via Bluetooth® connection make installation quick and easy. In addition, it can run diagnostics to view signal strength and tank obstructions. Learn more about Radar Technology and its benefits over other sensing technologies


RLI-80 >


Capacitive point level fuel level sensor

Capacitive point level fuel level sensor

The Gems’ ULS-100 Universal Level Sensor works with a wide variety of media. It eliminates failure caused by moving parts and works well in high-viscous, high-pressure, humid, and reflective applications. It does not rely on specific gravity or conductivity. It is simplifying product selection and reducing inventory with one common sensor type to replace them all.

ULS-100 >



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