“We started with five sensors and now we operate with 50. Before, we relied on customer calls and our own estimates. Now we have real-time visibility, which improves planning, reduces costs, and increases customer satisfaction.”
— Raúl Blanco, Sales Representative, Propenor (subsidiary of Cobo Tankers and Services Ltd)
The problem is not the fuel. It's not knowing how much is left.
If you operate a network of gas stations, manage tanks for end customers, or oversee supply in an industrial facility, you know that one of the biggest problems is not the fuel itself; it's not knowing how much remains in the tanks. Reactive management, that is, waiting for the customer to call, sending trucks without knowing the fill level, or discovering a run-out too late, carries a real and measurable cost: wasted journeys, dissatisfied customers and operational risk.
Fuel level telemetry solves this problem. But not all measurement technologies perform equally well in every scenario. Understanding the practical differences between ultrasonic and radar is not an academic exercise — it is the key to making the right deployment decision and protecting your margins.
What really sets the two technologies apart? What matters in the field.
Let's forget the specifications of the datasheet for ultrasonic and radar for a moment. These are the questions that really matter when you are going to deploy sensors in the facilities managed by a diesel distributor:
Accuracy and measurement range
Both technologies offer sufficient accuracy for the vast majority of diesel tanks under normal conditions. The difference appears at the extremes: ultrasound works very well in standard-sized tanks and calm environments, but it has a no-measurement zone near the sensor that can be a limitation when the tank is nearly full or small. The PCR radar has a very reduced no-measurement zone, works in taller tanks without losing reliability, and does not require choosing a different profile based on the size of the tank.
In practice: if your tanks are homogeneous, accessible and of standard size, ultrasound perfectly covers the job. If you manage facilities of different sizes or need a single technology that works in all cases without adjustments, the PCR radar is more versatile.
Influence of environmental conditions
This is the criterion that most clearly differentiates the two technologies in real-world deployments. Ultrasonic performs well in stable environments with constant temperatures and no vapour. Difficulties arise in summer, in above-ground outdoor tanks, or at sites where fuel vapour builds up as temperatures rise: these vapours can interfere with measurement, foam generated during filling can produce incorrect readings, and sudden temperature swings between day and night introduce small but cumulative deviations.
PCR radar is engineered to disregard all of this. Radar waves pass through fuel vapour without attenuation, foam does not deceive the signal, and the technology does not rely on air temperature inside the tank to calculate distance. An integrated temperature sensor compensates for any remaining signal variation.
In practice: in a buried tank in a temperate climate, ultrasonic rarely causes problems. In above-ground tanks under summer sun, or at sites with significant thermal cycling, PCR radar delivers more consistent and reliable readings.
Type of tank and stored product
Ultrasound is ideal for tanks where the temperature is stable and vapours are low. It is suitable for diesel, AdBlue, and oils under normal conditions. Where it loses ground is in outdoor above-ground tanks in warm climates, in high installations, or with high-viscosity products that tend to generate foam.
PCR radar is suitable for any tank configuration: buried, above-ground, horizontal, vertical, small or large. It is compatible with DERV, fuel oil, heavy oils and high-viscosity products prone to foaming. Its narrow signal beam also reduces reflections from the inner tank walls, improving measurement quality throughout.
In practice: a single technology for the entire fleet of tanks, regardless of their size, shape, or location.
Installation and maintenance
Both technologies install equally simply at the tank aperture, in a matter of minutes, without specialist tools. Ultrasonic sensors are tolerant of minor alignment deviations and do not require precise millimetre positioning. An annual inspection to remove any build-up of dirt or fuel residue is advisable.
The PCR radar features a fully integrated, sealed antenna — no exposed components and no surfaces requiring cleaning. It can be fitted behind a plastic or glass cover without requiring direct contact with the tank interior. Maintenance is effectively zero throughout the device's service life.
In practice: once the PCR radar is installed, it is forgotten. No periodic checks, no cleaning, no maintenance visits.
Energy consumption and battery life
Ultrasonic technology has a structurally low consumption per measurement: the physics of the acoustic principle is inherently efficient. Batteries last several years without the need for replacement.
The PCR radar consumes slightly more power during measurement due to the greater complexity of the radio frequency circuit, but the standby consumption is very low. With low measurement frequencies —common in fuel level telemetry— the battery life is equally long. The difference between the two technologies becomes more noticeable if very frequent measurements are configured throughout the day.
In practice: for the standard use case of a diesel distributor, the difference in consumption between the two technologies is small and should not influence the decision.
Cost
Ultrasonic carries a lower unit hardware cost and uses simpler, well-established electronic components. It is the most economical option for large-scale rollouts where site conditions are favourable. In challenging installations, however, measurement errors can generate operational costs that erode the initial savings.
Radar has a slightly higher unit cost, although the difference has narrowed in recent years thanks to the emergence of pulsed coherent radar technology. The module design is simple, with few additional components. Savings on field visits, measurement errors, and maintenance usually offset the higher initial price in medium and large installations.
In practice: when total cost of ownership is considered — not hardware cost alone — PCR radar tends to be the more cost-effective choice in demanding environments or across large fleets.
What is the right choice for your situation?
Choose the Ultrasonic Sensor if:
Your tanks are buried, in a calm environment and stable temperature.
The unit cost is the deciding factor and the environment does not present adverse conditions.
You operate domestic heating, agricultural operations with buried tanks, or small industrial installations with stable conditions.
Choose the PCR Radar if:
You operate outdoor above-ground tanks in areas with hot summers.
You have gas centres, service stations, or medium to large industrial installations.
You are looking for a single technology that works reliably in any scenario without adjustments or surprises.
You manage mixed fleets where you need a single platform for all types of tanks.
The two technologies coexist in NivelWatcher precisely because diesel distributors manage different realities. And both are managed from the same cloud platform, with a single interface.
The differential value: automatic self-calibration
One of the biggest headaches in large-scale IoT deployments is the initial setup. NivelWatcher solves this with automatic self-calibration.
The process adjusts the level measurement automatically, without requiring physical tank dimensions to be entered or any manual commissioning procedure in the field. The engineer simply selects the tank geometry (vertical cylindrical, horizontal cylindrical, prismatic, etc.) and the nominal capacity in litres. The sensor handles the rest.
“This is also where our automatic calibration adds real value: helping to reduce field setup time and ensuring consistent measurements from day one,” says Alberto Puras, Business Development Manager at Celestia TST.
The result is a distance-volume conversion function specific to each individual tank, which improves reliability and reduces reading errors from day one.
Installation in under a minute. No manual calibration. No commissioning visits.
One platform, two technologies, measurable impact
NivelWatcher is not just hardware. Level data is transmitted in real-time via LoRaWAN, Sigfox, or cellular networks (NB-IoT / LTE Cat-M) to a cloud platform that allows:
To visualise the level of all your tanks in real-time (mobile, tablet, desktop).
To receive automatic low-level alerts before a stockout occurs.
Analyse consumption patterns to optimise routes and restocking frequencies.
Integrate via API with ERP, CRM, planning tools, and BI platforms.
Automate orders and confirm deliveries without manual intervention.
Where to start? The path our customers follow
Most start with a PoC of 5 to 10 sensors in their most representative facilities. In 4 to 6 weeks, you have real data on your consumption patterns, without complex integrations or large initial investments.
If the results justify it, we move to a pilot, where we connect with your systems and activate automatic restocking alerts. Scaling comes when the operations team has gained confidence in the data and management can see the impact on distribution costs.
No pressure. With a responsive team.
🔽 Download the detailed comparison guide: Comparison LevelWatcher | Celestia TST
🎥 LevelWatcher in action:https://www.youtube.com/watch?v=pmFKIGY7OL8
The answer is not “one is better than the other”. Both technologies coexist in the NivelWatcher solution precisely because each scenario has its particularities. Here are the questions you should ask yourself.
Then, the ultrasonic sensor is your option: proven, efficient, long battery life and economical.
The R02 radar maintains accuracy where ultrasonic may fail.
The NivelWatcher R02 has ATEX certification to operate in potentially explosive atmospheres.
Do you want NivelWatcher working in your tanks?
Tell us your scenario and we will let you know within 24 hours which technology fits and how we can structure a PoC for you.