Accurate control complex shape fuel tank of city buses

Fuel monitoring in fuel tanks of buses

LLC «Rīgas satiksme», Latvia
fuel monitoring in complex shape fuel tanks of buses
city buses
DUT-E S7 wireless fuel level sensors + GPS telematics unit
  • accurate fuel tank control,
  • improved fleet efficiency,
  • automation of documentation
  • Fuel monitoring in fuel tanks of buses


    LLC «Rīgas satiksme», Latvia


    fuel monitoring in complex shape fuel tanks of buses


    city buses


    DUT-E S7 wireless fuel level sensors + GPS telematics unit


    1) accurate fuel tank control,
    2) improved fleet efficiency,
    3) automation of documentation


    LLC “Rīgas satiksme” was founded in 2003 and now is a part of municipality of Riga. Main field of activity is transportation of passengers, mainte- nance of parking lots, and provision of vehicles for rent. Transport of “Rigas satiksme” runs on 74 routes – 6 tram, 18 trolleybus and 50 bus lines. The company’s trams, trolleybuses and buses cover about 45 million km annually.

    3800+ employees

    500+ city buses

    140 million passengers transported per year


    The fleet includes buses for public city transportation: Icarus, Mercedes-Benz Solaris Urbino and Mercedes-Benz Citaro.

    Fuel monitoring system was installed on:

    Mersedes-Benz Citaro O530 (with two-axles)
    Mersedes-Benz Citaro О530L (with three-axles)
    Mersedes-Benz Citaro О530G (three- axle articulated).

    Maximum passenger capacity is 147 – 177, engine power − 185 – 260 kW, fuel tank volume −200 – 400 liters.

    Fuel consumption monitoring on Mercedes-Benz Citaro O530G city bus

    Fuel control on city (town) bus Mercedes-Benz Citaro O530L

    Fuel consumption monitoring on Mercedes-Benz Citaro O530 bus

    Fuel consumption monitoring on fuel tanks with irregular form

    Bus fuel tanks


    Customer had to deal with problem of fuel monitoring in fuel tanks of buses. Accurate data on remaining fuel helps to plan operating hours of bus on the route, place and time of refuelings.

    Passenger buses are designed in such a way that passenger cabin has maximum capacity. Place for fuel tanks is chosen “according to leftover principle” – near wheel arches, in the space between sheathing and body panels. It is impossible to mount fuel tank of large capacity with a form of parallelepiped or cylinder there. Therefore, fuel tanks of buses are usually of a complex shape.

    It is impossible to accurately measure fuel level in such fuel tanks using only standard float sensor. Lever of standard sensor cannot move freely throughout the entire height of fuel tank.

    Approximate fuel monitoring with an accuracy of “half a tank, give or take” did not suit the customer. So, it was necessary to install accurate fuel tank monitoring system with measurement inaccuracy not more than ± 1%.


    SIA Autonams telematics system provider proposed to install fuel tank monitoring system, based on DUT-E S7 wireless fuel level sensors and GPS telematics unit.
    DUT-E S7 measures fuel level in fuel tank with accuracy of 0,1 mm. Fuel data is transmitted using wireless S7 Technology via BLE-channel (Bluetooth 4.X Low Energy) to receiver – telematics unit with BLE. It is also possible to monitor data on the screen of Android smartphone or tablet. Data is transferred without pairing with receiver, simultaneously to several devices – in BLE radio mode.

    Installation of fuel tank monitoring system based on DUT-E S7 takes place twice
    as fast as when installing standard capacitive sensor – there is no need to lay
    connecting cables behind the sheathing of passenger’s compartment. Errors
    during electrical connection of sensor to telematics unit are eliminated. DUT-E S7 operates without external power supply. Built-in battery provides completely autonomous operation for 5 years.

    DUT-E S7 wireless fuel level sensor

    Three DUT-E S7 sensors in a fuel tank of a complex shape – accurate fuel tank measurement without blind spots

    Each fuel tank was equipped with two or three sensors. This made it possible to accurately measure fuel volume in such a case. When several sensors are installed in fuel tank, monitoring system provides fuel measurement without “blind spots” – so that, measurement inaccuracy does not exceed ± 1%, regardless of the amount of fuel in tank.
    Data on fuel volume is transmitted to Teltonika telematics unit and, thereafter, to telematic service − Skybrake vehicle tracking system.

    DUT-E S7 wireless fuel level sensor

    Ilmārs Piebalgs,
    Technoton’s partner in Latvia

    “To monitor fuel in complex shape tanks of buses, we offered to install DUT-E S7 fuel level sensors. Firstly, installation of wireless sensors takes a minimum time – there is no need to lay a cabling system. Secondly, S7 Technology allows connecting several sensors to a single monitoring telematics unit directly, without using any additional devices. Thirdly, it is possible to monitor fuel not only on telematics service, but also on the screen of smartphone with the help of mobile application.”


    Fuel tank monitoring system, based on wireless DUT-E S7 fuel level sensors and telematics units, was installed on 80 buses. Despite complex shape of fuel tanks, these sensors measure fuel volume with inaccuracy not more than ± 1%, and also determine the amount of fuel filled in.

    Data on fuel level in tanks come to Skybrake vehicle tracking system. Manager of “Rigas satiksme” in real-time monitors current fuel remaining in tank of each bus and makes decision on the possibility of further work or necessity of bus refueling. Skybrake vehicle tracking system allows to control fuel in tank (current volume, refueling/draining). Fuel data is sent to specialized software for automatic drafting of reporting documentation – itinerary and trip ticket, reports for State Revenue Service.

    Technical specialist, “Rigas satiksme”*

    “DUT-E S7 fuel level sensors are the best option for fuel control in bus tanks. Installation of devices took little time – we didn't have to remove buses from the routes and our company did not suffer losses due to idle time. Accurate fuel data comes in real time and without interruption. Rīgas satiksme now plans to equip another 220 buses with fuel tank monitoring system to improve fleet efficiency."

    * Data is hidden from public access to comply with GDPR requirements. Details on the project can be disclosed upon signing NDA and with the consent of our partner.

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