SCR AdBlue pressure sensor, component description

B14.40-0015-08

1 Metering unit

Arrangement

The AdBlue pressure sensor (4) is fastened to the outside of the metering unit (1). The metering unit (1) is located close to the last cylinder head cylinder.

4 AdBlue SCR (17B05) pressure sensor

Task

The AdBlue (4) pressure sensor captures the AdBlue pressure at a measuring point inside the metering unit (1) and transmits the information to the engine control module (MR), as an electrical tension signal.

B14.40-0023-11

Composition

The AdBlue (4) pressure sensor consists of a threaded stainless steel housing and an electrical connector.

The inside of the AdBlue compressed air pressure sensor contains, as a measuring element, a silicon membrane fitted with measuring strips. These measuring strips are electrical resistors that, during their expansion, modify their resistance (piezoresistive principle). The AdBlue (4) pressure sensor is fitted with a drilling, through which the AdBlue can penetrate up to the membrane. The AdBlue (4) pressure sensor is an active sensor. i.e., it is supplied with a tension.

Function

The AdBlue actuating on the pressure sensor (4), presses the internal membrane. This pressure that causes the membrane, when expanding, to modify its electrical resistance on the measuring strips. With these pressure modifications, occur the resistance increase or decrease of the measuring strips

The variations of electrical resistance are transmitted in defined intervals as analog signals to the control module (MR).

The control module (MR) calculates the corresponding pressure, starting from the resistance values.