The third version of SOJI Capacitive Fuel Level Sensor Series, giving an complete solution for most popular GPS Trackers with digital output signal (RS485).

General description 

LIGO SP – RS485 is a special improvement line, a product of the research team of Soji fuel level sensor. Changes in the mechanical design help the sensor achieve high accuracy and durability.

  • Measurement accuracy up to 99.5%.
  • Length  reduction up to 80 % of the initial length of the measuring probe.
  • Automatic recognization of new length after cutting feature (this feature can be enable or disable by software on PC).
  • Wide range working temperature from -40°C – +85°C.
  • Screen filter is mounted on the measuring probe tubes to protect measuring probe electrodes from mud and water.
  • IP67 waterproof.
  • Advanced filter algorithm and temperature compensation.
  • Configuration,update firmware through software on PC .
  • Easily to installing and sealling.


Parameter Value
DC input voltage, V 9-37
Standard length  (L),mm 700, 1000, 1500…up to 6000 mm
Power consumption(W)Typical


At short circuit on analog output, maximum



Measuring period, s 1
Output interface for measured values RS-232, RS-485
Message interval, s 1…60
Averaging time, s from 0…120
Measuring error, % ±0,5
Baud rate, bit/sec 2400, 4800, 9600, 19200, 38400, 57600, 115200
Input current, mA Max 20
Working temperature, °C -45 to 105
Ingress protection rating, IP IP67
DAC resolution, bit 12
Working principle (Capacitive Sensor)
Average service life, years 8



Constantly changing fuel characteristics can dramatically impact the result of fuel measurements and cause confusion in statistics. For example, factors such as changes in temperature, vehicle motion – causing errors in fuel-level calculations of up to 30%.

In order to achieve greater works, SOJI SP-RS485 Capacitive Fuel Level Sensor uses algorithm to compensate the effect of these changes and guarantee unprecedented accuracy of 99.5% in all conditions.

Therefore, SOJI SP-RS485 Digital Fuel Level Sensor reduces maintenance and re-calibration needs with the ability to compensate for errors in initial calibration, an issue that affects 20% of installed sensors. It provides accurate statistics for fleet owners and builds trust for installation partners who can confidently deliver on promises of accuracy.

In compare to Technoton Dut-E Sensor, Soji gives an equivalent solution in terms of quality whereas cutting the cost to a half.

Apart from Analog Version, SOJI Fuel Sensor is also available in Analog and RS232 signal standard, giving customers more options to suit with current operating system. Find out more at: SOJI SP-RS232 Fuel Level Sensor or SOJI SP-AF Analog Fuel Level Sensor.