Andrew D. Koffman

Publications

Comparison of a 1 nF Capacitor with a 1 kΩ Resistor Using a Digital Impedance Bridge

March 27, 2024

Author(s)

Yicheng Wang, Stephan Schlamminger, Dean G. Jarrett, Alireza Panna, Andrew D. Koffman

This paper reports our effort to improve a digital impedance bridge. The limit of the bridge resolution and stability is less than 3 parts in 10^9 for the

Measurement of the frequency dependence of four terminal-pair air capacitors with a vector network analyzer

October 6, 2023

Author(s)

Stephan Schlamminger, Andrew D. Koffman, James W. Schmidt, Bryan C. Waltrip, Yicheng Wang

Four terminal-pair air capacitors are important transfer standards to calibrate LCR meters up to a frequency of 10 MHz. We report a simple and new method to

New Method for Determining Time Constant of Resistors

March 21, 2023

Author(s)

Yicheng Wang, Dean G. Jarrett, Andrew D. Koffman, Stephan Schlamminger

We report a new method for determining the time constant of ac resistors with values around 10 kΩ, using a digital impedance bridge for comparison of two

Comparison of a 100 pF Capacitor with a 12906 Ω Resistor Using a Hybrid Impedance Bridge

December 31, 2021

Author(s)

Mona Feige, Stephan Schlamminger, Andrew D. Koffman, Dean G. Jarrett, Shamith Payagala, Alireza Panna, Bryan C. Waltrip, Michael Berilla, Frank Seifert, Yicheng Wang

The Design and Self-Calibration of Inductive Voltage Dividers for an Automated Impedance Scaling Bridge

October 12, 2021

Author(s)

Bryan C. Waltrip, Svetlana Avramov-Zamurovic, Andrew D. Koffman

The design and construction of an inductive voltage divider (IVD) for use in impedance bridge applications in the 20 Hz to 20 kHz frequency range is described

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Andrew D. Koffman (Fed)

Publications