Recent developments in the NIST ac-dc difference calibration service for thermal transfer standards

This paper presents a brief summary of the ac-dc difference calibration service for thermal transfer standards at the National Institute of Standards and Technology in Gaithersburg, MD. Related topics discussed include automated calibration systems, research into a new cryogenic thermal transfer standard, fabrication of thermal converters using semiconductor processing techniques, and a high-voltage comparator system based on a binary inductive voltage divider.