Initial NIST AC QHR measurements

Initial NIST AC QHR Measurements

We demonstrate that dc quantized Hall resistance (dc QHR) guideline properties and dc and ac QHR values can be measured without changing sample probe lead connections at the QHR device, and report ac QHR values that converge to the dc QHR value when using four-terminal-pair ac QHR measurements. This was accomplished during one cooldown using single-series and quadruple-series connections outsid...

Uncertainty in NIST Force Measurements

This paper focuses upon the uncertainty of force calibration measurements at the National Institute of Standards and Technology (NIST). The uncertainty of the realization of force for the national deadweight force standards at NIST is discussed, as well as the uncertainties associated with NIST's voltage-ratio measuring instruments and with the characteristics of transducers being calibrated. T...

NIST Mechanisms for Disseminating Measurements

The national responsibilities assigned to the National Bureau of Standards (NBS) early in the last century for providing measurement assistance and service are carried out today by the four programs that comprise the National Institute of Standards and Technology (NIST) Office of Measurement Services (OMS). They are the Calibration Program (CP), the Standard Reference Materials Program (SRMP), ...

Qhr 10/6/02

NIST Reference Goniophotometer for Specular Gloss Measurements

The current global economy has increased international competition and the need to improve the quality of many manufactured products. Appearance measurements are used to determine the quality and acceptability of a variety of products from textiles to machine finishes. Since the manufacture and marketing of these products is international in scope, the methods, instruments, and standards for th...