gf1440b3018a

SCR air humidity and air temperature combination sensor, component description

Typ gf · Thema 14.40 · Version 0400 · 2016-02-12

Gültig für: ENGINE 924.9 in MODEL 368, 384.0/2, 979.2 with CODE (MS5) BlueTec 5ENGINE 926.9 in MODEL 368, 382.17/18, 384.0 with CODE (MS5) BlueTec 5

Nicht verfügbar in „de“; angezeigt wird Englisch.

Einordnung

Funktionsgruppe 1 Motor › 14 Auspuffkrümmer, Motorbremse, Abgasreinigungsanlage › 14.40 Abgasnachbehandlung, AdBlue — Baureihe 368 (Baumuster 002, 004, 006, 104, 106, 115, 117) · Baureihe 382 (Baumuster 171, 177, 178, 185, 188, 189) · Baureihe 384 (Baumuster 063, 067, 076, 078, 223, 233) · Baureihe 979 (Baumuster 276, 277)

EinPAS 15 Motor › 15.40 Abgasanlage/Abgasnachbehandlung › 15.40.12 Sensor/Schalter/Leitungssatz — Baureihe 368 (Baumuster 002, 004, 006, 104, 106, 115, 117) · Baureihe 382 (Baumuster 171, 177, 178, 185, 188, 189) · Baureihe 384 (Baumuster 063, 067, 076, 078, 223, 233) · Baureihe 979 (Baumuster 276, 277)

Gilt auch für Motoren/Getriebe: 924 ***, 924 995, 924 996, 924 998, 926 ***, 926 997, 926 999

GF14.40-B-3018A

SCR air humidity and air temperature combination sensor, component description

12.02.16

ENGINE 924.9 in MODEL 368, 384.0/2, 979.2 with CODE (MS5) BlueTec 5

ENGINE 926.9 in MODEL 368, 382.17/18, 384.0 with CODE (MS5) BlueTec 5

SCR air humidity and air temperature combination sensor, component description

B14.40-0052-06

Represented on vehicle 382.177

Arrangement

3 Combined sensor of air humidity and air temperature SCR (17B01)

The combined sensor of air humidity and air temperature SCR (3) is located on the outside part of the intake tube, between the air filter and the turbocharger.

Task

The combined air humidity and temperature sensor (3) measures the temperature and determines the water steam content in the intake air.

SCR air humidity and air temperature combination sensor, component description

B14.40-0139-05

Represented in vehicle 384.223

3 Combined sensor of air humidity and air temperature SCR (17B01)

Composition

The combined sensor of air humidity and air temperature SCR (3) consists of separate components to determine the air humidity

The components to determine the air humidity are "active", i.e., are supplied with tension. Unlike the components for measuring the temperature which are "passive".

Humidity sensor

To transmit the humidity, inside the sensor is a plate type capacitor with two plates and a layer of humidity sensitive synthetic material as insulator. The insulator is applied to the bottom plate. In the top plate there is an electrode permeable to water steam.

Temperature sensor

An NTC "Negative Temperature Coefficient" resistor is located inside the sensor to measure the temperature and means, that the electrical resistance diminishes when the temperature increases.

Function

Transmission of the humidity

The synthetic material layer, between the two capacitor plates, is sensitive to humidity and can store water molecules. The capacity and electrical conductivity changes, according to the humidity value of the air taken in.

This change in resistance also depends highly on the temperature and has to be compensated by the air temperature measurement. The fumes which modify the electric capacitor are transmitted, in established intervals as analog signals, to the MR control unit. The MR control unit calculates the relative humidity of the air, considering the air temperature determined value.

Measuring of air temperature

The air that flows, depending on the temperature, influences the temperature measurement of the element inside the sensor and, therefore, the amount of electrical resistance.

The values which change in the electric resistance are transmitted in established intervals as analog signals, to the MR control unit. Based on the value of the resistance, the MR control unit calculates the corresponding temperature.