FOFN Products
Wired Capacitive Fuel Level Sensor

Capacitive fuel level sensors utilize the principle of radio-frequency capacitance measurement combined with dynamic dielectric analysis compensation technology to detect the liquid level of gasoline, diesel, hydraulic oil, and other weakly conductive liquids. The probe length can be customized according to the depth of the fuel tank or container, and the sensor outputs liquid level data via digital or analog signals, making it suitable for fuel level monitoring in vehicles, construction machinery, vessels, and stationary storage tanks.
The capacitive fuel level sensor is designed for high-precision fuel level monitoring. It detects changes in the dielectric properties of the liquid via a probe, automatically performs medium compensation, and converts the liquid level into a stable, continuous linear output signal. Compared to mechanical float-type sensors, the CR606 has no elastic components or moving parts, offering greater stability after installation and making it more suitable for long-term in-vehicle and industrial applications.
The sensor’s detection range is 80–1,400 mm, and it supports customization based on tank depth. Optional threaded or flanged mounting options are available to accommodate different fuel tanks, storage tanks, and equipment configurations. The device features a wide operating temperature range and an IP67 protection rating, making it suitable for environments such as vehicle vibrations, construction sites, ships, and outdoor storage tanks.
Depending on project requirements, the CR606 is available in either a digital output or analog output version. Digital output supports one of the following: RS232, RS485, CAN, or TTL; analog output supports a 4–20 mA current signal or 0–3.3 V, 0–5 V, or 0–10 V voltage signals. When GPS positioning, 4G remote transmission, or platform monitoring is required, the device can be integrated with the corresponding positioning terminals or data transmission equipment.
Project Parameters
Product Models
CR606 Series
Measurement Principle
RF Capacitance Measurement
Operating Voltage
DC 5V (4.5–9V) / DC 12V / DC 24V (9–36V)
Operating Current
5–10 mA (except for 4–20 mA analog products)
Pressure Range
-0.1 MPa–0.1 MPa
Scope of Detection
80–1,400 mm, customizable
Lead Length
1000 mm, customizable
Probe diameter
Φ16 mm / Φ19 mm / Φ22 mm
Operating Temperature
-35°C to +75°C
Storage Temperature
-40°C–+85°C
Temperature resistance of the probe
-50°C to +150°C
Installation Instructions
Threaded mounting: M20×1.5, M27×2; flange mounting available upon request
Protection Rating
IP67
Explosion-proof rating
Ex ia IIC T6 Ga (Intrinsically Safe)
Accuracy Class
Class 1.0 (Actual accuracy depends on probe length and calibration conditions)
Digital Output
RS232 / RS485 / CAN / TTL; select one output type per unit
Analog Output
4–20 mA; 0–3.3 V / 0–5 V / 0–10 V
4–20 mA Version Power Supply
24V DC
Key capabilities
- RF capacitance measurement, stable fuel level data
- Dynamic medium compensation to minimize the effects of temperature and medium changes
- No moving parts; shock- and vibration-resistant
- Detection range: 80–1,400 mm; custom lengths available
- Supports RS232, RS485, CAN, and TTL digital outputs
- Supports 4–20 mA, 0–3.3 V, 0–5 V, and 0–10 V analog outputs
- IP67 protection rating, suitable for challenging environments
- Supports threaded mounting and custom flange mounting
- Can be integrated with GPS/4G devices to enable remote fuel level management
- Intrinsically safe versions are available for specific explosion-proof applications.