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1. Direct Current and Low Frequency

Karl-Peter Lallmann

The DKD Technical Committee “Direct Current and Low Frequency“ deals with the calibration of electrical quantities in the frequency range from  0 Hz to 1 MHz. The Technical Committee currently consists of 79 members, including accredited calibration laboratories, interested persons and representatives of the PTB. Considering the size of the committee, the realization of the technical work is a difficult task. Therefore, small groups of members have been established for the preparation of calibration guidelines. These groups are particularly supported by the Association of German Engineers (VDI/VDE-GMA Division 3.12). Thus, over the last 20 years, the calibration guideline VDI/VDE/DGQ/DKD Sheet 2622 et seq. has been created. Through the translation into English, the calibration guideline series aims to reach a greater degree of acceptance outside the German-speaking countries. 

The Technical Committee meets once a year for an exchange of information. The meeting agenda includes reports from the board of the DKD, the respective sector committee of the DAkkS and the Technical Advisory Board 5 of the Accreditation Advisory Board of the Federal Government. Other topics are • the current state of the VDI/VDE/DGQ/DKD guidelines and discussions • information provided by and/or submitted to the Technical Committee  “Measurement Uncertainty“ • guidance concerning calibration technology • guidance concerning the evaluation of measurement results

Especially the organization and realization of comparison measurements is a current topic. Here, we rely heavily on the support of the PTB. These and many more topics are covered in close cooperation with the PTB, with representatives of the DAkkS and members of other Technical Committees.

In addition to the relevant VDI/VDE/DGQ/DKD guidelines, the Technical Committe so far has published the following calibration guideline:

 • DKD-R 1-1: Measurement and generation of  small AC voltages with inductive voltage divider