A refractometer has a housing ( 1 ), a measurement cell ( 8 ) arranged in the housing ( 1 ), and a lid unit ( 2 ). The lid unit has a base plate ( 3 ) with a cutout ( 7 ) allowing access to the measurement cell, and a lid ( 4 ) for covering the measurement cell. The lid is connected to the base plate by way of a hinge. The lid unit also has a lid insert ( 11, 17, 18, 28, 31, 35, 39 ) that is arranged replaceably in the lid. The lid unit ( 2 ) is detachably connected to the housing by means of a connecting element that is itself connected to the base plate.
1. A refractometer, comprising:
a housing;
a measurement cell, arranged in the housing, in which is received a sample to be measured; and
a lid unit, the lid unit comprising:
a base plate, a cutout therein allowing access to the measurement cell of the refractometer;
a lid for covering the measurement cell;
means for hingedly connecting the lid to the base plate; and
a lid insert, replaceably arranged in the lid; and
a connecting element that detachably connects the lid unit to the housing by connecting the housing to the base plate.
2. The refractometer of claim 1 , wherein:
the means for hingedly connecting comprises two parts that are coupled to one another so the lid separates from the base plate.
3. The refractometer of claim 2 , further comprising:
an optical shield that prevents external light from penetrating the measurement cell, the optical shield comprising at least a part of the lid insert.
4. The refractometer of claim 3 , further comprising:
a pressing insert that spreads a sample in the measurement cell, the pressing insert comprising at least a part of the lid insert.
5. The refractometer of claim 3 , further comprising:
a sealing insert that insulates the measurement cell from the outside environment, the sealing insert comprising at least a part of the lid insert.
6. The refractometer of claim 2 , wherein:
the connecting element comprises a magnetic connection.
7. The refractometer of claim 2 , wherein:
the connecting element comprises a snap-on connection.
8. The refractometer of claim 2 , wherein:
the connecting element comprises a bayonet fastening.
9. The refractometer of claim 1 , further comprising:
a means for controlling temperature, comprising at least a part of the lid insert.
10. The refractometer of claim 1 , further comprising:
a means for changing the pressure in the measurement cell, comprising at least a part of the lid insert.
11. The refractometer of claim 1 , further comprising:
a means for charging the measurement cell with a gas, comprising at least a part of the lid insert.
12. The refractometer of claim 1 , further comprising:
a sensor for recording a physical and/or chemical property of a sample.
13. The refractometer of claim 1 , further comprising:
a lip which extends peripherally as a part of the base plate.
14. The refractometer of claim 13 , further comprising:
a drain channel on the peripherally extending lip.
15. The refractometer of claim 1 , wherein:
the base plate comprises, or at least has a surface coating that comprises, a chemically resistant material.
16. The refractometer of claim 1 , further comprising:
an optical shield that prevents external light from penetrating the measurement cell, the optical shield comprising at least a part of the lid insert.
17. The refractometer of claim 1 , further comprising:
a pressing insert that spreads a sample in the measurement cell, the pressing insert comprising at least a part of the lid insert.
18. The refractometer of claim 1 , further comprising:
a sealing insert that insulates the measurement cell from the outside environment, the sealing insert comprising at least a part of the lid insert.
19. A lid unit, connected to a refractometer housing in which a measurement cell is arranged, comprising:
a base plate, a cutout therein providing access to the measurement cell;
a lid for covering the measurement cell;
means for hingedly connecting the lid to the base plate; and
a lid insert, replaceably arranged in the lid.