Voraussetzung und Grenzen der Qualitätssicherung in der Wasseranalytik

A discussion is presented on the conditions required and limitations of the guaranteeing of quality in water analysis as the basis for the necessary standardization of analytical methods. The following concepts are of particular importance: principle of analysis, method of analysis, technique of analysis, specification for analysis, measured value, analytical value, result of measurement, result of analysis, precision, repeatability, reproducibility, detection limit, determination limit, sensitivity and rate of retrieval. Prequisite for the ensuring of quality proper are the standard addition method and the ring analysis. In the water analysis the guaranteeing of quality is of particular importance due to the multifarious matrix as well as for the interpretation of the analytical results as a basis for important decisions in the national economy.     

The Karlsruhe Dynamo Experiment. A Mean Field Approach

At the Forschungszentrum Karlsruhe an experiment is in preparation which it is hoped, in view of the geodynamo and other cosmic dynamos, that a homogeneous dynamo will be demonstrated and investigated. This experiment is discussed within the framework of mean-field dynamo theory. Results are presented concerning kinematic cylindrical mean-field dynamo models reflecting some features of the experimental device, as well as results of detailed calculations of the -effect that apply to arbitrarily high magnetic Reynolds numbers. On this basis estimates of the excitation conditions of the dynamo are given and predictions concerning the geometrical structure of the generated magnetic fields are made.