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A calibration system of a 3.5 mm coaxial power sensor was implemented using transfer standards with 7 mm coaxial or K-band waveguide input connectors. A 7 mm-3.5 mm or WR42-3.5 mm adapter was used to form a combined transfer standard. The effective efficiency of the combined transfer standard was obtained. The 3.5 mm coaxial power sensor was calibrated using the well-known direct comparison method...
The International Avogadro Coordination aims at determining the Avogadro constant by measuring the molar mass, lattice parameter and density of a 28Si single crystal. As the temperature dependent quantities are measured in different apparatuses, the consistency of the temperature measurements has to be proven. An electronic temperature reference and a standard platinum resistance thermometer (SPRT)...
The design and correction factor evaluation of a WR-15 (50 to 75 GHz) rectangular waveguide microcalorimeter is presented. This new microcalorimeter will be the US national standard for power from 50 to 75 GHz. It can measure the effective efficiency of a wider variety of transfer standards than can the previous microcalorimeter. It has also been designed so that its correction factor can be experimentally...
The paper summarizes current efforts to develop a novel alternating (AC) sampling standard at the PTB in cooperation with ZERA- and EMH-GmbH in Germany. This instrument shall operate in the frequency range of 40 Hz to 5 kHz and serve as a transfer standard, allowing measurements with basic accuracies of some muV/V at 50 Hz to be made. It is intended to ensure improved traceability to the PTB primary...
The density of an isotopically enriched 28Si crystal is evaluated. A transfer standard of the hollow silicon cylinder is prepared and its density is determined by the hydrostatic weighing (HW). The 28Si crystal is then compared with the hollow silicon for the determination of the density by the pressure-of-flotation (PF) measurement.
The following topics are dealt with: fundamental constant, resistance, ac-dc transfer, voltage, power, impedance, magnetic variable, time and frequency measurements and standards; calibration of measurement techniques and set-ups; photonic and magnetic methods; radiofrequency measurement methods.
An intercomparison of calibration systems for instrument transformers between Korea Research Institute of Standards and Science (KRISS) and National Research Council of Canada (NRC) with many different ratios at 60 Hz was performed using six portable transfer standards consisting of two current transformers (CTs) with current ratios of 5 A/5 A up to 20,000 A/5 A and four voltage transformers (VTs)...
This paper describes the design and verification of current shunts for AC-DC transfer measurements in the range 20 A to 100 A. The measured AC-DC current transfer difference of the 100 A shunt is -36 muA/A at 100 kHz with an uncertainty of 200 muA/A.
New thin-film range resistors have been developed at the National Metrology Institute of Japan (NMIJ) to reduce the voltage dependence of AC-DC transfer differences that have appeared in the processes of the step-up procedures over 300 V. The occurrence of voltage dependence is partly due to rising ambience temperature that may cause changes in the resistance of the resistor and the temperature dependence...
A number of international comparisons of calibration systems for capacitors up to 1 nF were conducted in the past at frequencies about 1000 Hz. This intercomparison of large value capacitors calibration systems between VNIIM and NRC was done at frequencies of 50 Hz, 60 Hz, and 1000 Hz. The comparison was implemented with a set of transfer standards, developed by VNIIM, with nominal capacitance values...
This paper describes the realization of AC-DC current transfer difference at SP with emphasis on the realization at high frequencies, which is based on modeling of single junction thermal converters by their reactive and loss components. The estimated expanded uncertainty is 6 muA/A at 1 MHz. Also level dependence of planar multijunction converters is reported.
A new set of ac-dc resistance transfer standards are being developed for use in the BIPM quadrature bridge. These resistors use commercial thick film resistance elements, whose small ac-dc difference is calibrated against a calculable coaxial reference. The improved stability of the new resistors should reduce the overall uncertainty of the quadrature transfer.
The paper presents a new AC-DC transfer measurement system for voltages up to 1000 V and frequencies up to 1 kHz based on a precision inductive voltage divider. Preliminary evaluations show the possibility of standard uncertainties of less than 3 muV/V at 1000 V.
National Physical Laboratory India (NPLI) is the premier research & development center and the National Metrology Institute, which provides traceability in measurements by calibration throughout the country. Low Frequency voltage and current are very important quantities in electrical metrology. The standards for LF voltage and current are established by assigning AC-DC transfer difference to...
NIST recently reported the first application of a quantum AC Josephson voltage standard (ACJVS) for calibration of thermal transfer standards in the 1 kHz to 10 kHz frequency range. This paper describes preliminary work on extending its frequency calibration range up to 100 kHz by correcting systematic errors due to voltage leads.
This paper describes the development of a microwave power sensor calibration system using the direct comparison transfer method with a resistive power splitter. The system setup, its uncertainty analysis and measurement results are discussed.
An ac-dc transfer measurement system based on a programmable Josephson voltage standard (PJVS) is being developed. Performance of the standard with dc and synthesized ac bias has been characterised. The first ac-dc transfer measurement results indicate agreement with conventional standards of the order of 1 muV/V at frequencies up to 40 Hz.
We report first results obtained with the Two Way Satellite Time and Frequency Transfer (TWSTFT) between LNE-SYRTE and NTSC using the IS-4 commercial geostationary satellite at 72degE operating in Ku band. This work is part of the activities recommended by the CCTF working group on TWSTFT. The detailed study of the measurement uncertainty is presented, with particular attention to the fluctuation...
The automation of ultra-high resistance measurements at the National Institute of Standards and Technology (NIST) in the range 1 TOmega to 100 TOmega has been completed with the use of a programmable XY positioning system to facilitate the guarded connection of multiple standard resistors to an automated dual-source bridge. Automated guarded switching that is immune to leakages to ground is critical...
Optical fiber power meter (OFPM) linearity standards of NMIJ (Japan) and NIST (USA) are compared using a commercial OFPM as a transfer standard at 1310 nm and 1550 nm over a power range [-60 dBm, 0 dBm]. At both wavelengths the comparison indicates an agreement between the two laboratories within the combined uncertainty. At 1550 nm the uncertainties are larger, which is attributed to unstable operation...
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