Comparing Two Diesel Level Sensor Technologies: Capacitance vs Radar
In fuel storage tank monitoring systems, selecting the right sensor technology significantly impacts measurement accuracy, reliability, and system lifespan. Below is a technical comparison of two sensor lines provided by Daviteq.
CAP10 - Precision Capacitance Level Sensor
Operating Principle:
Measures changes in capacitance between electrodes as the fuel level changes (due to variations in dielectric constant εr).
Technical Specifications:
Measurement range: 1500mm (standard), extendable up to 2500mm
Resolution: 1mm
Linearity: 0.1% full scale
Probe material: Aluminum A6061, PA plastic
Operating temperature: -20 ~ +70°C (optional -40 ~ +85°C)
IP67 protection
Output interfaces: 4-20mA, RS485, LoRaWAN, Sub-GHz, Sigfox, NB-IoT, LTE Cat M1
Advantages:
- High resolution and linearity
Ultra-low power consumption, ideal for battery/solar-powered IoT
Cost-effective solution
Limitations:
Requires initial calibration per diesel type (due to εr variation)
Affected by probe fouling or water contamination in fuel
Suitable Applications:
- Small to medium tanks (horizontal/vertical)
- Indoor or outdoor environments
- Stable fuel type (consistent εr)
- Low-budget projects
- Low-power wireless IoT systems
RLC - Miniature Radar Level Sensor
Operating Principle:
Uses 60 GHz pulse radar to calculate fuel level by measuring time-of-flight of reflected radar pulses.
Technical Specifications:
- Measurement range: 0.2m ~ 18m
- Accuracy: ±3 ~ 5mm
- Resolution: 1mm
- Wetted parts: Teflon, POM
- Operating temperature: -40 ~ +85°C
- IP67 protection
- Output interfaces: 4-20mA, RS485, LoRaWAN, Sub-GHz, Sigfox, NB-IoT, LTE Cat M1
Advantages:
Non-contact measurement, unaffected by fuel type or contaminants
No need for calibration by fuel type
Reliable under harsh outdoor conditions- Versatile for tanks with complex shapes
Limitations:
Higher cost than capacitance sensors- Dead zone of ~20cm
- Requires careful installation to avoid sidewall reflections
Suitable Applications:
- Large tanks with heights over 1.5 meters
- Outdoor and high-variation environments
- Multi-type diesel systems
- Applications requiring high stability and minimal maintenance
Quick Comparison Table
| Criteria | CAP10 (Capacitance) | RLC (Radar 60 GHz) |
|---|---|---|
| Accuracy |
Very high (requires calibration) | Extremely high (no calibration needed) |
| Fuel type impact |
Requires calibration per diesel | Ignored |
| Water contamination |
Affected | Negligible effect |
 Probe fouling |
Affected over time | Not affected |
 Outdoor use |
Good durability | Excellent durability |
| Dead zone |
None | ~20 cm |
| Investment cost |
Low | Higher |
| Battery/solar IoT |
Ideal | Suitable |
Summary Recommendation
- Choose CAP10 for small-to-medium tanks, cost-sensitive projects, and environments with stable fuel conditions and good maintenance.
- Choose RLC for long-term stability, outdoor use, large tanks, or when avoiding calibration and minimizing environmental sensitivity is critical.
For project-specific support or consultation, please contact the Engineering Department or submit your request via Daviteq Contact Page.