# US 2012/0073540 A1 · Extraction tube for emission measurement systems

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- Number: US 2012/0073540 A1
- Document ID: US20120073540A1
- Status: Published application
- Kind: A1
- Application number: 13/137,891
- Filed: 2011-09-20
- Published: 2012-03-29
- Earliest claimed: 2010-09-23
- Assignees: AVL List GmbH
- Inventors: Georg Gangl
- Web page: https://patentgrep.com/patent/US20120073540A1

## CPC

- G01N 15/00: Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

An extraction tube (1) for emission measurement systems for the exhaust gas of internal combustion engines has at least two exhaust gas extraction points (5) and connecting pieces to at least two sampling lines. In order to allow, with little required space and little constructional efforts, multiple sampling from the exhaust gas of internal combustion engines, at least two tubes (4) run parallel to each other over a portion of the length of the extraction tube (1), wherein each tube (4) is provided with an exhaust gas extraction point (5).

## Claims

### Claim 1

An extraction tube for emission measurement systems for exhaust gas of internal combustion engines, the extraction tube having at least two exhaust gas extraction points and connecting pieces to at least two sampling lines, wherein over a portion of the length of the extraction tube (1) at least two tubes (4) run parallel to each other, wherein each tube (4) is provided with an exhaust gas extraction point (5).

### Claim 2 (depends on 1)

The extraction tube according to claim 1, wherein the total cross-section of all tubes (4) is equal to the cross-section of the preceding section (3) of the extraction tube (1).

### Claim 3 (depends on 2)

The extraction tube according to claim 2, wherein the length of each tube (4) corresponds at least to the nine-fold diameter of this tube (4), wherein one length of at least the six-fold diameter is provided upstream of the first exhaust gas extraction point (5) and one length of at least the three-fold diameter is provided downstream of the last exhaust gas extraction point (5).

### Claim 4 (depends on 1)

The extraction tube according to claim 1, wherein flow guiding devices (6) are provided which distribute the exhaust gas flow uniformly between all present tubes (4).

### Claim 5 (depends on 4)

The extraction tube according to claim 4, wherein a substantially conical portion is arranged as flow guiding device (6) upstream of the beginning of the tubes (4).

### Claim 6 (depends on 1)

An emission measurement system for the exhaust gas of internal combustion engines, comprising at least one analysis and evaluation device for the exhaust gas and a plurality of sampling lines from the exhaust gas system of the internal combustion engine to said or to each of the analysis and evaluation devices, and an extraction tube (1) according to claim 1 which can be connected to the exhaust gas system of the internal combustion engine.