In this paper, the primary (Josephson-based) and secundary (Zener-based) measurement standard systems used for calibration of solid state voltage standards (Zeners) at Inmetro are described, as well as the calibration method, the related equations and uncertainty budgets.

Traditional calibration of dc voltage high accuracy digital voltmeters (DVMs) using conventional and Programmable Josephson Voltage Standards at INMETRO show improvements between 73.7 % and 98.3 % when compared with a regular calibration technique. Some calibration results as well as DVM linearity and gain drift analysis (up to 10 V range) are presented and discussed in this paper.

For some time it had been suspected that values assigned to NIST working standards of mass were some 0.17 mg/kg larger than mass values based on artifacts representing mass in the International System of Units (SI). This relatively small offset, now confirmed, has had minimal scientific or technological significance. The discrepancy was removed on January 1, 1990. We document the history of the...

The low energy (Eβmax = 66.945 keV ± 0.004 keV) β-emitter 63Ni has become increasingly important in the field of radionuclidic metrology. In addition to having a low β-endpoint energy, the relatively long half-life (101.1 a ± 1.4 a) makes it an appealing standard for such applications. This paper describes the recent preparation and calibration of a new solution Standard Reference Material of 6...

In the early history of photometry, sources such as candles, lamps, or blackbodies were always used as standards to realize, maintain and transfer the photometric base unit. Even after the advent of photodetectors in the early twentieth century, lamps have been traditionally used to maintain and transfer the units of luminous intensity and luminous flux. In this case, a group of primary standar...

The primary aim of the INTERGROWTH-21(st) Project is to construct new, prescriptive standards describing optimal fetal and preterm postnatal growth. The anthropometric measurements include the head circumference, recumbent length and weight of the infants, and the stature and weight of the parents. In such a large, international, multicentre project, it is critical that all study sites follow s...

Gauge blocks continue to be essential reference artifacts in manufacturing because of their simple geometry, but also because they can provide very high accuracy for a reasonable cost. The calibration technique of optical interferometry can directly link gauge block central length to the distance light travels in vacuum in 1/299792458 of a second, the definition of the International System of U...

Modern confocal microscopes enable high-precision measurement in three dimensions by collecting stacks of 2D (x-y) images that can be assembled digitally into a 3D image. It is difficult, however, to ensure position accuracy, particularly along the optical (z) axis where scanning is performed by a different physical mechanism than in x-y. We describe a simple device to calibrate simultaneously ...

National Institute of Standards and Technology, Gaithersburg, MD 20899-0001 The Low Background Infrared Calibration Facility (LBIR) at the National Institute of Standards and Technology has been in operation for calibration measurements of ihe radiant power emitted fn>rn infrared radiation (IR) sources, such as cryogenic blaclcbodies, for more than 2 years. The IR sources arc sent to NIST by Cu...