The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The technical characteristics of four different designs of single junction thermal converters (SJTCs) are evaluated in this paper. This variety in the designs represents the technical trials in developing enhanced thermoelements and in minimizing the values of their transfer errors. A traceable automated system was used to investigate the time responses, DC reversal difference, and the voltage and...
A multiplier based on thermal converters was developed for the use in broad band power measurements. The topology of the multiplier is of simple design and suppresses its static errors by means of an improved summing circuit. It employs fast synchronous ac-dc transfer technique to shorten the measurement time. The evaluated measurement uncertainties are of the order of some 10-6 for frequencies up...
A waveform synthesizer adopting a programmable Josephson voltage standard has been developed, which can produce stepwise sinusoidal waveforms with few hundred quantum voltage levels. For synthesis of waveforms, individual cells on the Josephson array chip were promptly biased using a 7-channel current source with 14-bit resolution. As an application, the synthesizer was utilized as a fast-reversed...
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...
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.
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...
Dry etching is employed in the fabrication of new planar, thin-film multijunction thermal converters (MJTCs) on quartz membranes and crystalline quartz chips at NIST. The use of crystalline quartz as a material for the membrane and for the chip improves the performance of the MJTC in the frequency range from 100 kHz to 100 MHz. Simulations of the ac-dc voltage transfer difference for a heater resistance...
An experiment was set up to evaluate a sensor suite containing an affordable commercially available capacitance to digital converter and a simple custom-built capacitance sensor. A set of surface mount capacitors was thoughtfully assembled for evaluation purposes. The results show good short-term stability, allowing the effective use of the sensor suite in an object classification application.
We propose a thin-film thermal converter with resistive sensing of the temperature rise of the heater. Vanadium oxide (VO2) is used for the sensing resistors. This paper shows the simulations used for the basic design. The high temperature coefficient of its resistivity and the optimization of the design envisage a sensitivity of 10 VldrW-1.
We have measured stepwise-approximated sinewaves generated by a programmable Josephson voltage standard with several different output configurations. These data are analyzed to characterize the dominant error mechanisms for rms applications, such as ac-dc difference measurements of a thermal voltage converter (TVC). We discuss the impact of the dominant systematic errors on the overall uncertainty...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.