4 Reasons why Smart Sensors Are the Hidden Heroes of UAV Performance
July 3, 2025, 5 minute read
July 3, 2025, 5 minute read
In recent years, drones have become an essential part of our lives: from rapid deliveries and search-and-rescue missions to agriculture and firefighting.
Few people know that behind those remarkable performances lie smart sensors called flowmeters. In this article, we are going to take a deep dive into how and for which kinds of UAVs flow meters can improve the operability of unmanned drones.
For any drone developer, the #1 goal is to make the UAV (unmanned aerial vehicle) as lightweight as possible. Why? Because less weight means more flight range, bigger payload capacity and easier maneuvering while in the air.
It may sound like a paradox to use additional sensors for improving the performance of an UAV, as the key feature to improve factors is keeping the whole system as light as possible.
In a world of UAVs, the following uses and applications come to mind:
The limiting factors are:
-Precise range calculations;
-Knowing exactly when you hit the "point of no return”;
-Safer and reliable operations;
-Accuracy under high vibrations and pulsating flow
Flowmeters measure how much fuel or liquid is flowing through the system. For this we will look at two distinct cases. Battery powered UAVs and internal combustion UAVs. Here's what they bring in:
When it comes to pushing drones to their limits, flying long distances or carrying out endurance missions, efficient fuel use is everything. To make sure a drone can reach its target (and, just as importantly, make it back safely), pilots and operators need precise data on the drone's effective range. Traditionally, most drones rely on level sensors to estimate how much fuel remains. These sensors are popular because they're cheap and widely available. But here's the catch: they aren't very accurate when the fuel tank gets closer to zero. Just when you need the most error-free reading, their measurements become unreliable… not great if you're trying to calculate the exact point of no return. That's where ultrasonic fuel flow meters come in. By tracking fuel consumption from the very moment of takeoff, flowmeters provide real-time, highly accurate data on how much fuel the drone has used and how much is left, with an impressive reading accuracy of ± 0.5 %, even under challenging real world conditions.
In aviation, weight distribution is everything. On drones heavier than 2 tons, stabilizing fuel across multiple tanks ensures an efficient flight. Flowmeters track how much fuel is pumped between tanks, making sure the drone stays balanced even if one engine fails in complex maneuvers like VTOL (vertical take-off and landing).
Without this, smaller drones with lightweight pumps can struggle to maintain stability. Weighing an aircraft while airborne ranges from difficult to impossible, a very accessible solution for this is precise measurement of the fuel quantity in each tank of the aircraft.
Ultrasonic flowmeters are preferred because they combine durability, precision, and flexibility. They handle pulsating or irregular flows effortlessly, are highly resistant to wear, and can work with many types of fluids, from fuel to coolants or agricultural chemicals, making them the most versatile choice for drone applications.
Heat is one of the most underestimated risks to drone longevity and safety. Batteries, motors, and onboard electronics all generate heat, particularly during high-demand operations like firefighting or agricultural spraying. Without precise cooling, the risk of overheating can compromise mission success and
shorten component lifespan.
Allengras flowmeters play a vital role here by continuously monitoring cooling fluid flows. This ensures that all parts of the system stay within safe temperature limits, extending the drone's life and allowing operators to push the machine's performance even under extreme conditions
For drones used in irrigation or spraying, dosing precision directly affects both cost and effectiveness. Allengras micro flowmeters make sure the exact amount of liquid (water, pesticide, or fertilizer) is delivered to the right place, maximizing efficiency and reducing waste on every flight.
Introducing the Micro Flow Meter (2nd Gen) and PUM Fuel Flow Meter
Allengras ultrasonic flowmeters are the hidden heroes inside today's top-performing drones. By providing ultra-accurate, real-time measurements under tough conditions, they help UAVs fly farther, last longer, and operate with maximum efficiency.
When you invest in smart sensor technology like Allengras, you're not just adding a piece of hardware, you're unlocking the full potential of every drone
