Level sensors with metallised sleeve ensure a continuous reliability of the safety shutoff system.


No malfunction with biofuel


Biofuel as per EN 14213 consists of a certain percentage of fatty acid methyl ester (FAME). Typical admixtures today are up to 20 %. The higher the FAME content, the greater the water content in fuel. In fuel oil tanks, this creates an environment even more susceptible to the growth of microorganisms such as bacteria and fungi. This may cause the level sensor to malfunction and ultimately disable the safety shut-off system.

Possible fatal consequences: damage to the building, soil contamination, environmental damage, groundwater pollution, long-term odour problems and immense consequential costs. The owner or operator is fully responsible for all damages.



The metallised surface largely prevents the growth of microorganisms.

Therefore, the universal withdrawal system with level sensor chain for battery tank facilities as well as all AFRISO level sensors feature metallised sleeves. It provides mechanical protection of the PTC thermistor, is open at the bottom and has a slot at the side so that the fuel oil can easily reach the PTC thermistor. The metallised surface of the new sleeve and the new shape of the slot largely prevent the growth of microorganisms and improve the long-term reliability of the level sensor. Owners, tenants and petrol tanker operators can rest assured that the fuel oil always reaches the PTC thermistor for reliable shut-off.






Examples of sludge and fungi on level sensors – without metallised sleeve

Level sensor chain – the best protection against damage caused by overfilling


AFRISO "universal withdrawing system"
with level sensor chain for protection against
overfilling in non-communicating battery tanks. 










Usually, only a single sensor is installed in tank facilities. Level differences in the individual tanks of such facilities at the beginning of or during the filling process are not an uncommon phenomenon. There is a chance that the first tank filled is not equipped with a level sensor. There is a high risk of overfilling and fuel oil spillage.

The AFRISO level sensor chain protects battery tank facilities against overfilling. The officially required level sensor is contained in one of the tanks. However, each additional tank of the facility contains a float switch to limit the filling level; this level switch is connected to the wiring box of the level sensor. A terminating plug at the last tank closes the current circuit.

The current circuit of the level sensor which is supplied from the tank vehicle during the filling process and which serves as a safety shut-off system now also includes float switches. The filling process is immediately stopped if any of the tanks of the facility reaches the maximum level. If the float switch stops the filling process, the additional volume caused by the shut off delay and the content of the filling line is considered. Since the filling level of all tanks must be visually detectable or indicated by means of a level indicator, the tank that has caused the shut off can be immediately identified.

Additional information on the level sensor chain: