Quality assurance methods in the German federal dose rate measurement network: periodic examination of measuring posts

Within the German gamma dose rate measurement network a procedure for the periodic examination of its 2150 measuring posts has been developed which makes it possible to test the complete post including electronics and data transfer without taking it out of service for a long time. Examinations are carried out by the six measurement centres. The procedure was started in April 2001. Until November 2002 90 % of all measuring posts had been examined. 98 % of them passed the criteria; in the other cases the cause mostly was due to probe specific effects. As a consequence of these examinations it became evident that for new dose rate tubes the specifications of the physical properties of the tubes and the related electronics had to be corrected in different points. Additionally a small amount of different types of tubes used in the dose rate network could be identified which are due to development phases within the past years. In this lecture the basic considerations, organizational regulations and the effects of the periodic examinations procedure are presented. (orig.)