Calibration of lVDs at frequencies up to 1 MHz by permuting capacitors

摘要

A device has been constructed which pelvi1utes eleven nominally equal 50_pF capacitors in a bridge to calibrate the l0:1 and l:10 f l0 ratios of i11ductive voltage dividers (IVD_s) at frequencies up to l MH_z. A compact design, whicl1 is important for high frequency measurements, was implemented using printed circuit boards and ceramic NPO dielectric capacitors. The capacitors are individually shielded to reduce errors from stray capacitances. Comparisons made with results from an existing NPL method of calibrating lVD_s at frequencies up to l00kH_z and with results from a recently developed high-frequency fOur terminal-pair bridge show that better than l0 parts-Per-million uncertainty has been attained at l MH_z.