DC Resistance
- Start Date : 9 February, 2027
- Start Time : 8:00am
- End Date : 9 February, 2027
- End Time : 5:00pm
- Address : Garden 2, N Tower
No Schedule
Abstract
At the National Institute of Standards and Technology (NIST), the U.S. representation of the ohm is based on the quantum Hall effect, which is maintained and disseminated at various resistance levels by working reference groups of standards. NIST provides a calibration service for standard resistors with nominal decade values in the range of 10−4 Ω to 1013 Ω. High-current standard resistors, known as shunts, with nominal values as low as 10−5 Ω can be calibrated at currents as high as 3000 A.
This tutorial will cover the fundamentals of DC resistance metrology with the aim of providing knowledge and measurement techniques to assist metrologists in making accurate and reliable DC resistance measurements. The art of resistance metrology will be explained beginning with the quantum Hall effect that serves as the basis of the US representation of the ohm and the measurement techniques and instrumentation used in scaling and disseminating resistance at different decade levels from the quantum Hall resistance standard. The effects of pressure, temperature, voltage, drift, and current on resistor measurements will be explained and methods will be shown how to account for these parameters. An uncertainty budget will be built to demonstrate key elements that affect a resistor’s measured value at different decade levels.
Alireza Panna
Alireza Panna was born in Mumbai, India. He received the B.S. degree in Electrical Engineering from the University of Maryland, College Park, MD, USA, in 2013. From 2012 to 2013 he worked as a guest researcher for the National Institutes of Standards and Technology, Gaithersburg, MD, USA, where he was involved in the magnet characterization for the NIST-4 Kibble balance. From 2013 to 2017 he was with the National Institute of Health, Bethesda, MD, USA, where he worked on controls and characterization of various x-ray imaging modalities. Since 2017 he has been with the National Institute of Standards and Technology where he is involved in the Metrology of the Ohm and the Quantum Conductance Projects.
Dean Jarrett
Dean G. Jarrett started working at the National Bureau of Standards (now the National Institute of Standards and Technology) in 1986 as a co-op student, where he worked on automation of resistance measurement systems. He received the B.S. degree in Electrical Engineering from the University of Maryland in 1990 and M.S. degrees in Electrical Engineering and Applied Biomedical Engineering from The Johns Hopkins University in 1995 and 2008, respectively. Research interest include high resistance measurements and standards, low current measurement techniques, and graphene quantum Hall resistance standards and measurement systems. Since 2014 he has been project leader for the Metrology of the Ohm Project at NIST. He is a fellow of the Institute of Electrical and Electronics Engineers.