In process measurements technology or in industrial measurements technology, apparatuses for handling liquid samples, especially for automatic removal of a liquid sample from a sample-taking location, are especially used for monitoring the quality of applied or manufactured liquids and liquid mixtures. Examples of such apparatuses are automatic sample takers, which, at predetermined points in time, withdraw from the sample-taking location a liquid sample with a predetermined volume, and collect this in sample containers. The collected samples can later be further examined and analyzed in the laboratory. Sample takers are also frequently used when monitoring and optimizing the cleaning effectiveness of a clarification plant, when monitoring activation basins and the clarification plant outlet or for controlling filler metering.
Besides a sufficient metering accuracy, the most important requirements for so-applied apparatuses, especially automatic apparatuses, for handling of liquids—especially automatic sample takers—are robustness, ease of operation and the assurance of sufficient working and environmental safety. At the same time, the effort involved and especially the costs for manufacture and maintenance of such apparatuses should be kept as low as possible, even though such apparatuses, as a rule, make use of a large number of individual components.
Known in the state of the art are modularly embodied apparatuses for handling liquid samples, especially for removal of liquid samples from a sample-taking location. The modular construction is intended to make the apparatuses robust and flexible in form. At the same time, a modular construction facilitates the manufacture of such apparatuses, and permits a retrofitting of an existing apparatus through addition of further modules with new functionalities.
In the international publication WO 2007/057432 A1, a modularly constructed sample taker is described, which can optionally be expanded with an analysis module, and thus is retrofittable to an automatic analysis device. A cooling/temperature control module is also provided, which, like the analysis module, can be embodied as a retrofittable, modular, structural unit. The temperature control module is accommodated in a module housing, which, by means of an adapter unit (which can, for example, be composed of mutually engaging, push-in rails) can be releasably connected with the housing of the sample taker.
The sample taker described in WO 2007/057432 A1 includes, as supply and metering system, a sample withdrawal unit, which is composed of at least a suction hose, a pump and a distributor station for the liquids which are supplied by means of the pump. The sample withdrawal unit can likewise be embodied as a module. The sample withdrawal unit is a component of a wet space, which is separated from additional modules. As a component of the wet space (which forms, as a whole, one module), the sample withdrawal unit cannot easily be replaced with another sample withdrawal unit (for example, with a sample withdrawal unit which works according to another functional principle). This would mean a certain effort for modification of the wet space module.