Andrew D. Koffman

Publications

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

EVALUATION OF INDUCTIVE VOLTAGE DIVIDERS AND 10 nF CAPACITORS IN A CAPACITANCE CALIBRATION METHOD

October 12, 2021

Author(s)

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

Researchers within the Quantum Electrical Metrology Division at the National Institute of Standards and Technology (NIST) have implemented a calibration

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