Abstract: A cell and/or a measuring instrument are arranged for coulometric titration. The cell has first and second electrochemical half-cells, each of which is connected into a regulated circuit and each of which has an associated electrode. The second electrode (3) is immersed in an electrolyte (2) that is solid or solidified and fills a second housing (1). The second housing is closed, with charge and material exchange only possible through a diaphragm (4) that is disposed between the respective electrochemical half-cells. The electrolyte contains a first redox partner that, along with at least one second redox partner, is part of a redox system. The redox partners are selected to substantially suppress gas development inside the cell during operation. The first electrode and the second housing are disposed in a first housing so that at least the diaphragm and the first electrode are in contact with a sample during operation.

Abstract: A cell and/or a measuring instrument are arranged for coulometric titration. The cell has first and second electrochemical half-cells, each of which is connected into a regulated circuit and each of which has an associated electrode. The second electrode (3) is immersed in an electrolyte (2) that is solid or solidified and fills a second housing (1). The second housing is closed, with charge and material exchange only possible through a diaphragm (4) that is disposed between the respective electrochemical half-cells. The electrolyte contains a first redox partner that, along with at least one second redox partner, is part of a redox system. The redox partners are selected to substantially suppress gas development inside the cell during operation. The first electrode and the second housing are disposed in a first housing so that at least the diaphragm and the first electrode are in contact with a sample during operation.

Abstract: A method and system for testing the functional capability of an analytical instrument uses first and second blind samples. Each blind sample is a test substance with an amount of a parameter to be tested that is unknown to the user. Each blind sample is provided with an identification means with a unique identification. When the blind samples are tested by the user in the instrument being tested, the measurement values obtained and the unique identifications read are compared against predetermined values that are accessible to a test program configured as software on the analytical instrument. By comparison of the measurement values and the predetermined values, the functional capability of the analytical instrument is determined and the result is transmitted to an output unit of the analytical instrument.

Abstract: A method and system for testing the functional capability of an analytical instrument uses first and second blind samples. Each blind sample is a test substance with an amount of a parameter to be tested that is unknown to the user. Each blind sample is provided with an identification means with a unique identification. When the blind samples are tested by the user in the instrument being tested, the measurement values obtained and the unique identifications read are compared against predetermined values that are accessible to a test program configured as software on the analytical instrument. By comparison of the measurement values and the predetermined values, the functional capability of the analytical instrument is determined and the result is transmitted to an output unit of the analytical instrument.

Abstract: 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.

Abstract: 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.