Calibration of Capacitance Standards with a Quadrature Bridge
نویسندگان
چکیده
− National Metrology Institutes employ the quadrature bridge in the traceability chain to derive the farad from the ohm (represented with the quantum Hall effect). The bridge calibrates the capacitance product of the two capacitors being measured; a separate measurement with a ratio bridge is usually required to estimate each capacitor independently. We describe here a method which, by measuring three capacitance standards with the quadrature bridge only, permits to derive the value of each capacitor without resorting to other measurement systems. The method has been checked with an automated quadrature bridge at the level of 1 nF, and verified by measurement on a ratio bridge.
منابع مشابه
A Capacitance Measurement System Using an IVD Bridge
A new system to characterize the magnitude and phase characteristics of 1 pF to 1 F capacitance standards over the 50 Hz to 100 kHz frequency range is described. The system has been developed to provide measurement support for LCR meters and general impedance measurement services. It consists of an inductive voltage divider (IVD) bridge capable of accurately comparing two capacitance standards...
متن کاملResonance frequency of four- terminal-pair air-dielectric capacitance standards and closing the metrological impedance triangle
A new technique for determining the resonance frequency (f0) of four-terminal-pair air-dielectric capacitance standards is discussed. The resonance frequency is determined by measuring four parameters of the capacitance standards over a range of frequencies near f0. These parameters are the two-terminal-pair impedance coefficients as defined in an impedance matrix. From a knowledge of the four-...
متن کاملCalibration of dissipation factor standards
Working standards for dissipation factor (D) obtained by connecting a shielded three-tenninal capacitor in series with a shielded precision resistor have been developed for calibration purposes. Precision conductance boxes have been built for use with a single three-tenninallOOO pF gas capacitor standard to create dissipation factor standards having values from 2 x 10-5 to 1 X 10-2. The design ...
متن کاملDesign of a digital four-terminal-pair impedance bridge
The paper describes the design of a four-terminal-pair impedance bridge developed at INMETRO. Originally devised to work as a quadrature bridge for deriving the unit of capacitance (Farad) from a resistance (Ohm) or vice-versa, it allows the comparison of impedances in general with outstanding accuracy and measurement uncertainties bearing some 10 /
متن کاملTraceability Chain of the Capacitance Unit to Quantum Hall Effect at Inmetro - Four-terminal Coaxial Bridge
− This paper describes the development of a four-terminal coaxial bridge, part of the traceability chain of the capacitance unit to the quantum Hall effect, in construction at Inmetro. This bridge will also be used to calibrate AC resistance and high-value capacitance standards. Here we describe the final construction stages and preliminary measurements of the four-terminal coaxial bridge. We a...
متن کامل