Coherence of comparison results obtained by new inductance comparator bridge

Few years ago a high-precision multi-range comparator bridge KWL5 was constructed at Silesian University of Technology, Gliwice, Poland. The instrument enables 1:1 comparison of inductors from 100 μH to 10 H in the frequency range from 100 Hz to 10 kHz with the smallest uncertainty possible. Results of a coherence test performed for this instrument are presented here. The coherence investigation, commonly called the "triangle method", is a effective way to prove the lack of a most systematic errors and large random errors in the measurement procedure realized by the instrument.