Headquartered at Sale Marasino (Brescia, Italy), Euroswitch is renowned for its production of level sensors, pressure switches, temperature sensors, vacuum switches and rotation Sensors, besides the wide range of catalogue products, proposes its customers also the resistive fuel level sensors, for the control of non-conductive fluids like fuels and oils.
Such offer is fruit of the synergy with Mont.el (lead company of the homonymous network of which is part Euroswitch itself), technological leader in the design and implementation of highly reliable innovative sensors for the indication of the fuel level and reserve, mainly used in the sectors of agricultural and earth handling machines, in the motorcycle and shipbuilding industry.
The principle of the potentiometer obtained with a sliding contact
The operation of these sensors is based on the principle of the potentiometer obtained with a sliding contact, anchored inside a float in foamed nylon, which allows obtaining a variable resistance value depending on the level of the fuel sliding on an opportune FR4 gold printed circuit.
Opportunely sizing the number and the length of the sectors of the printed circuit (generally 15), it is possible to obtain a linearization of the measure that allows adapting the Mont.el sensor to whatever tank and type of instrument, both analogue and digital, as well as having a N.O. output contact in the sensor that closes to ground when the fuel level reaches the desired reserve value.
The presence of a plenum chamber allows strongly attenuating the oscillations. Upon request, by means of an additional electronic circuit, it is possible to have a check control, which in switching-on phase verifies the operations of the reserve warning light, switching it on for some seconds and during the normal operation introduces a signal delay, in order to avoid the light flashing in the rolling and pitching phases of the vehicle.
It is therefore a very precise and stable indicator in whatever operation condition. The electronic components are positioned in the flange and completely resin-coated to assure the necessary protection. Configured in this way, the resistive level indicator can be used in whatever tank containing non-conductive liquids (petrol, unleaded petrol, diesel etc.) and be indifferently mounted from the top or from the bottom with the maximum inclination of 25°.
A wide range of solutions
Other models are available. It is worth signalling the B5 model with ohmic resistive output for the control in continuous of petrol or diesel tanks used in the shipbuilding ambit.
We have then the resistive electromagnetic sensors, in the specific the mod. IMRI. Euroswitch has developed the IMRE level sensor with 4 – 20 mA analogue output, which shares the basic technical characteristics with the other sensors of the same range, that’s to say the capability of providing a linear and continuous output signal that, managed with a suitable instrument, indicates the liquid level inside a tank. The sensor contains a chain of reed contacts distanced one another by a 10 or 20 mm pitch, each of them connected with a resistance, and the magnet, mounted in the float, closes in succession the reed contacts positioned in the shaft, connecting the output to a point from time to time different of the resistance chain.