Apparatus for measuring the scattered light and method of testing a reception optics

1. An apparatus ( 10 ) for measuring the light scattered from a measured zone ( 12 ), the apparatus having a light transmitter ( 14 ) for transmitting a light beam ( 18 ) into the measured zone ( 12 ) and having a light receiver ( 22 ) with a reception optics ( 24 ) for detecting light scattered in the measured zone ( 12 ), wherein an adjustment unit is provided to change between a measuring mode in which the optical axes of the light transmitter ( 14 ) and of the reception optics ( 24 ) stand at an angle with respect to one another and intersect in the measured zone ( 12 ) and a test mode in which the optical axes of the light transmitter ( 14 ) and of the reception optics ( 24 ) are aligned in parallel with one another, wherein the light beam ( 18 ) successively sweeps over the reception optics ( 24 ) for recognizing contaminants, and wherein the reception optics ( 24 ) is rotatably held at a displaceable rotary axle ( 32 ); and the adjustment unit first rotates the reception optics ( 24 ) about the rotary axle until the optical axis of the reception optics ( 24 ) is in parallel with the optical axis of the light transmitter ( 14 ) in the test mode and then displaces the rotary axle ( 32 ) together with the reception optics ( 24 ).

2. An apparatus ( 10 ) in accordance with claim 1 ,

wherein the reception optics ( 24 ) is fastened to a first holding element ( 30 ) which is rotatably held at the displaceable rotary axle ( 32 ).

3. An apparatus ( 10 ) in accordance with claim 1 ,

the apparatus having a rotationally fixed second holding element ( 34 ) from which the rotary axle ( 32 ) starts.

4. An apparatus ( 10 ) in accordance with claim 3 ,

wherein the second holding element ( 34 ) is displaceably supported, in particular on at least one rail ( 36 ) or linear guide.

5. An apparatus ( 10 ) in accordance with claim 1 ,

wherein a first restoring element ( 38 ) is provided to push the reception optics ( 24 ) back into a starting position on the change from the test mode into the measuring mode.

6. An apparatus ( 10 ) in accordance with claim 1 ,

wherein the adjustment unit has a pushing element ( 46 ) which is displaceable in a straight line from a first position into a second position.

7. An apparatus ( 10 ) in accordance with claim 6 ,

wherein a chamfered surface ( 48 ) of the pushing element ( 46 ) is in contact with the reception optics ( 24 ) or with the first holding element ( 30 ).

8. An apparatus ( 10 ) in accordance with claim 1 ,

wherein a first abutment ( 40 ) is provided to end the rotational movement when the optical axis of the reception optics ( 24 ) is in parallel with the optical axis of the light transmitter ( 14 ).

9. An apparatus ( 10 ) in accordance with claim 1 ,

the apparatus having a rotationally fixed second holding element ( 34 ) from which the rotary axle ( 32 ) starts, wherein a first abutment ( 40 ) is provided to end the rotational movement when the optical axis of the reception optics ( 24 ) is in parallel with the optical axis of the light transmitter ( 14 ).

10. An apparatus ( 10 ) in accordance claim 1 ,

wherein a second restoring element ( 44 ) is provided to rotate the reception optics ( 24 ) back into a starting position on the change from the test mode into the measuring mode.

11. An apparatus ( 10 ) in accordance with claim 1 ,

wherein a second abutment ( 42 ) is provided, to rotate the reception optics ( 24 ) back at most up to and into the starting position.

12. An apparatus ( 10 ) in accordance with claim 1 ,

the apparatus having a rotationally fixed second holding element ( 34 ) from which the rotary axle ( 32 ) starts and wherein a second abutment ( 40 ) is provided at the second holding element to end the rotational movement when the optical axis of the reception optics ( 24 ) is in parallel with the optical axis of the light transmitter ( 14 ).

13. A method of testing a reception optics ( 24 ) of an apparatus for measuring the light scattered in a measured zone, the apparatus having a light transmitter ( 14 ) for transmitting a light beam ( 18 ) into the measured zone ( 12 ) and having a light receiver ( 22 ) with a reception optics ( 24 ) for detecting light scattered in the measured zone ( 12 ), wherein an adjustment unit is provided to change between a measuring mode in which the optical axes of the light transmitter ( 14 ) and of the reception optics ( 24 ) stand at an angle with respect to one another and intersect in the measured zone ( 12 ) and a test mode in which the optical axes of the light transmitter ( 14 ) and of the reception optics ( 24 ) are aligned in parallel with one another, wherein the reception optics ( 24 ) is scanned by a light beam ( 18 ) in a test mode in that the optical axis of the reception optics ( 24 ) is tilted until it is in parallel with the light beam ( 18 ) and is subsequently displaced in parallel, wherein the reception optics ( 24 ) is first tilted about a rotary axle ( 32 ) and the rotary axle ( 32 ) is subsequently displaced together with the reception optics ( 24 ).

14. An apparatus ( 10 ) for measuring the light scattered from a measured zone ( 12 ), the apparatus having a light transmitter ( 14 ) for transmitting a light beam ( 18 ) into the measured zone ( 12 ) and having a light receiver ( 22 ) with a reception optics ( 24 ) for detecting light scattered in the measured zone ( 12 ), wherein an adjustment unit is provided to change between a measuring mode in which the optical axes of the light transmitter ( 14 ) and of the reception optics ( 24 ) stand at an angle with respect to one another and intersect in the measured zone ( 12 ) and a test mode in which the optical axes of the light transmitter ( 14 ) and of the reception optics ( 24 ) are aligned in parallel with one another, wherein the light beam ( 18 ) successively sweeps over the reception optics ( 24 ) for recognizing contaminants, wherein the reception optics ( 24 ) is fastened to a first holding element ( 30 ) which is rotatably held at a displaceable rotary axle ( 32 ), wherein the adjustment unit has a pushing element ( 46 ) which is displaceable in a straight line from a first position through an intermediate position into a second position and comprises a chamfered surface ( 48 ) which is in contact with the first holding element ( 30 ); and the adjustment unit first rotates the reception optics ( 24 ) about the rotary axle by moving the pushing element ( 46 ) from the first position into the intermediate position taking along the first holding element ( 30 ) by the contact between the chamfered surface ( 48 ) with the first holding element ( 30 ) until the optical axis of the reception optics ( 24 ) is in parallel with the optical axis of the light transmitter ( 14 ) in the test mode and then displaces the rotary axle ( 32 ) together with the reception optics ( 24 ) by moving the pushing element ( 46 ) from the intermediate position into the second position so that the light beam ( 18 ) is moved over the reception optics ( 24 ).