Diesel particulate sensor

Abstract

A soot particulate sensor has a ceramic support made from an aluminum silicate, which is provided with a conductor path made of an intermetallic compound.

Claims

1. A soot particle sensor, comprising: a ceramic support on which there is arranged at least one conductor track which has parallel sections arranged at a distance from one another, ends of which are connected to electronics for determining electrical resistance of the conductor track, wherein the ceramic support is made of an aluminum silicate and the conductor track is made of an intermetallic compound, the ceramic support contains ceramic reinforcing fiber, the ceramic reinforcing fibers are formed by mullite fibers, and the aluminium silicate is dope with zirconium dioxide.

2. The soot particle sensor as claimed in claim 1, wherein the aluminum silicate is an island silicate.

3. The soot particle sensor as claimed in claim 2, wherein the island silicate is mullite.

4. The soot particle sensor as claimed in claim 2, wherein the ceramic support contains ceramic reinforcing fibers.

5. The soot particle sensor as claimed in claim 1, wherein the ceramic support contains ceramic reinforcing fibers.

6. The soot particle sensor as claimed in claim 1, wherein the intermetallic compound is molybdenum disilicide and/or an aluminide.

7. The soot particle sensor as claimed in claim 6, wherein the aluminide is titanium aluminide and/or iron aluminide.

8. A process for producing a soot particle sensor comprising a ceramic support on which there is arranged at least one conductor track which has parallel sections arranged at a distance from one another and the ends of which are connected to electronics for determining the electrical resistance of the conductor track, wherein the ceramic support is made of an aluminum silicate and the conductor track is made of an intermetallic compound, the ceramic support is formed by tape casting and sintering, and the ceramic support contains ceramic reinforcing fibers, the ceramic reinforcing fibers are formed by mullite fibers, and the aluminum silicate is doped with zirconium dioxide.

9. The process as claimed in claim 8, wherein a sheet formed by tape casting is dried after casting, at least one dried support is printed as green body with a printed pattern corresponding to the conductor track using a suspension containing the intermetallic compound in powder form and the printed sheet is sintered in order to form, by sintering of the printed pattern and sintering of the green body, the ceramic support provided with the sintered conductor track.

10. The process as claimed in claim 9, wherein the dried green body is printed with the suspension containing the intermetallic compound in powder form by screen printing.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The FIGURE schematically illustrates a soot particle sensor according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWING

(2) In the FIGURE, the soot particle sensor 1 has a plate-shaped ceramic support 2, for example composed of mullite, which is provided with a meandering conductor track 3, e.g. composed of molybdenum disilicide, whose ends 3a and 3b are connected to electronics (not shown) for determining the electrical resistance of the conductor track 3. The more soot particles, i.e. electrically conductive carbon particles, that bridge the parallel sections of the meandering conductor track 2, the greater is the reduction in the resistance of the conductor track 2, as a result of which the decrease in the resistance represents a measure for the soot loading of the sensor 1.

(3) In the FIGURE, the conductor track 3 is depicted as being broad in the interests of clarity. However, in actual fact it has a width of only, for example, from 30 to 300 m. The distance between neighboring meandering sections is also of this order of magnitude.

(4) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.