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AC/DC Transfer

Working Group 2.13


The Working Group 2.13 is responsible for the maintenance and dissemination of the electric units for capacitance and inductance as well as for AC-DC voltage transfer and AC-DC current transfer over a wide range of values and frequencies.

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Alternating voltage

Developments are ongoing to utilize Josehpson voltage standards to calibrate sources of alternating voltage.



Digitally assisted ratio bridges are developed to be used for the calibration of capacitance standards.

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This working group carries out calibrations of standards of accredited laboratories, of industry, of other national metrology institutes, and for research. The dissemination of the unit of inductance is performed from 1 µH to 100 H, and for the unit of capacitance from 1 pF to 10 mF, both in the frequency range from 50 Hz to 1 MHz.

Standards for AC-DC voltage transfer are calibrated in the range from 1 mV to 1000 V at frequencies from 10 Hz to 1 MHz, those for AC-DC current transfer in the range from 100 µA to 100 A at frequencies from 10 Hz to 100 kHz.

Measuring equipment for alternating voltage and alternating current can be calibrated in the ranges and at the frequencies indicated above.

The disseminated measurement results are based on the internationally agreed constants KJ-90 (Josephson constant) and RK-90 (von Klitzing constant).


Assessment of calibration laboratories for electrical quantities on behalf of the German Accreditation Body

Calibration laboratories are assessed on behalf of the German Accreditation Body (DAkkS).



The working group provides expert advice in the fields of metrology for impedances, for alternating voltage and current as well as for AC-DC transfer.


Measurement capabilities

Link to the calibration and measurement capabilities (available in German only)

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The working group presently does not offer any further information.

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