A Kelvin resistance bridge with the frequency range from dc to 100 kHz

For the accurate measurement and calibration of the famous Tinsley 5685 AC standard resistors, a new type of Kelvin resistance bridge working over frequency range from DC to 100 kHz is described. At the same time, a bridge substitution technique is used in which the unknown Tinsley resistor is compared to the standard of AC/DC calculable resistor with double helix arrangement. Through this bridge the frequency characteristics of these portable AC standard resistors with the resistance value from 1 Omega to 10 kOmega have been obtained, which will extend their frequency range in metrology calibration.