Component description for the fill level and SCR AdBlue temperature combination sensor

B14.40-0011-06

Arrangement

3 AdBlue reservoir

4 Combined AdBlue level and temperature sensor (17B02)

The combined AdBlue level and temperature sensor (4) is fastened to the outside of the AdBlue reservoir (3). And the arrangement and fastening of the AdBlue reservoir will depend on body model and make.

Task

The combined AdBlue level and temperature sensor (4) records the AdBlue level and temperature in the reservoir (3).

B14.40-0095-05

49.5 liters AdBlue reservoir

Composition

1 Float

2 Immersion tube

3 AdBlue reservoir

4 Combined AdBlue level and temperature sensor (17B02)

B14.40-0037-12

35 liter AdBlue reservoir

1 Float

2 Immersion tube

3 AdBlue reservoir

4 Combined AdBlue level and temperature sensor (17B02)

The combined AdBlue level and temperature sensor (4) contains separate components for the transmission of level and measurement of temperature.

Level sensor

The combined AdBlue level and temperature sensor (4) has an immersion tube (2) with an integrated resistive current to determine the filling level, comprised by Reed type contacts and a float (1), that contains a permanent magnet.

Temperature sensor

In the bottom end of the immersion tube (2) there is a NTC resistor, as a temperature measuring element. NTC means "Negative Temperature Coefficient" and means that the electric resistance decreases with the rise of the temperature.

Function

Determination of the filling level

The sensor for the determination of the filling level works according to principle of float with magnetic transmission. A ring shaped magnet installed on the float actuates, with its magnetic field through the wall of the immersion tube (2), small Reed contacts which, in a resistive measuring current (principle of tension divisor), derive uninterruptedly a measuring tension, which is proportional to the filling level.

The electric resistance values that vary according to the position of the float (1) are transmitted in predefined intervals as analog signals, by the chassis control module, to the engine control module (MR). This determines the corresponding filling level, based on the resistance value.

Determination of temperature

The AdBlue surrounding the combined AdBlue level and temperature sensor (4) influences, depending on its temperature, the measuring element inside it and, thus the electric resistance value.

The modified electric resistance values are transferred in pre-established intervals as analogic signals, by the SCR chassis control unit. This permits it to deduce the corresponding temperature from the resistance value.