Quasi-Balance Four-Terminal Resistance Bridge

Abstract

A kind of quasi-balance four-terminal ac resistance bridge has been constructed. The electronic inductive voltage divider provides high accurate voltage ratios for the bridge at a wide frequency range from 20 Hz to 10 kHz. The Wagner network with electronic circuit containing followers and amplifiers makes the voltage ratio unaffected by internal loading of ratio winding. Amplifiers are used to eliminate voltage drop on the lead wire connecting two resistors. Sampling method is used to measure the complex voltage ratio. The bridge can measure resistances from 1 to 1 M . The optimal uncertainty for resistance of 100 and 1 k is 2 × 10 −7 at 1 kHz.Index Terms-Bridge circuits, impedance measurement, lead voltage elimination, quasi-balance, resistance measurement, sampling method, voltage dividers.

Lead-Wire-Resistance Compensation Technique Using a Single Zener Diode for Two-Wire Resistance Temperature Detectors (RTDs)

“…This method was able to eliminate the unfavorable effect on the measurement caused by lead wires, but it cannot obtain the specific lead-wire-resistance values, in addition, its interface circuits and power circuits were complicated due to the OPAMPs. Similar methods using OPAMPs were also published in Reference [8][9][10]. All of these bridge-based interface circuits used a three-or four-wire method, except for Reference [6].…”