| 1. |
- Bergman, Anders, et al.
(författare)
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A Constant Voltage Source Based on a Mercury Battery
- 1993
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9456 .- 1557-9662. ; 42:2, s. 365-367
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Tidskriftsartikel (refereegranskat)abstract
- A constant voltage source based on a stable mercury battery has been developed at SP (Swedish National Testing and Research Institute). By using as active current compensation technique, the inherent high stability of a mercury battery can be retained up to a load current of several milliamperes.
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| 2. |
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| 3. |
- Båvall, Lennart
(författare)
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Determination of coating thickness of a copper-plated steel wire by measurement of the internal wire impedance
- 1998
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9456 .- 1557-9662. ; 47:4, s. 1013-1019
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Tidskriftsartikel (refereegranskat)abstract
- A measurement of the internal impedance of a copper-cladded steel wire by a quote measurement of the voltage across and current through the wire can be used as a method to determine the cladding thickness. An electromagnetic model accounting for the internal impedance with different values of the coating thickness on a steel wire is described. Numerical calculations based on this model have been carried out and compared with measurements. An example shows how the method can be used to model a steel wire with a coating of copper to find the expected impedance as a function of coating thickness
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| 4. |
- Gunnarsson, O., et al.
(författare)
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A method for calibration of partial discharge calibrators
- 1999
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9456 .- 1557-9662. ; 48:2, s. 453-456
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Tidskriftsartikel (refereegranskat)abstract
- A method for calibration of partial discharge calibrators has been developed based on passive integration of the induced charge. The voltage over a known capacitor is measured by a calibrated digital sampling voltmeter and the charge is calculated as the voltage multiplied by the capacitance. The best achieved uncertainty is ±2% with a coverage factor k = 2. © 1999 IEEE.
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| 5. |
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| 6. |
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| 7. |
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| 8. |
- Rydler, Karl-Erik
(författare)
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High precision automated measuring system for AC-DC current transfer standards
- 1993
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9456 .- 1557-9662. ; 42:2, s. 608-611
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Tidskriftsartikel (refereegranskat)abstract
- An automated measuring system for AC-DC current transfer standards has been developed at the Swedish National Testing and Research Institute (SP). The use of a guard makes intercomparisons with ppm precision possible at frequencies up to 100 kHz. Two multijunction thermal converters are used for evaluating the uncertainty of the system.
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| 9. |
- Simonsson, Pär, 1963-, et al.
(författare)
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A comparison of power measuring systems
- 1997
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9456 .- 1557-9662. ; 46:2, s. 423-425
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Tidskriftsartikel (refereegranskat)abstract
- An automatic zero-power-factor standard has been designed and compared with a digital sampling wattmeter standard. The agreement of the two power measuring standards at 120 V, 5 A, and zero power factor is within a few uW/VA. The paper describes the standards, the phase errors and uncertainties of the two standards
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| 10. |
- Simonsson, Pär, 1963-, et al.
(författare)
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Level dependence of AC-DC transfer devices
- 1999
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9456 .- 1557-9662. ; 48:2, s. 395-398
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Tidskriftsartikel (refereegranskat)abstract
- A new method based on summing of phase controlled AC voltages makes it possible to compare thermal voltage converters with a ratio of 2:1 without introducing any error due to level dependence. The method is used to determine the level dependence of thermal voltage converters up to 1 kV and 100 kHz. The level dependence is compared to the change of AC-DC transfer difference due to power dissipation in the range resistor and due to DC-effects in the thermal converter. The results for two investigated TVC's indicate that the power dissipation is the only cause of level dependence in the range resistor of a high voltage TVC.
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| 11. |
- Svensson, Stefan, 1958-, et al.
(författare)
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A measuring system for the calibration of power analyzers
- 1995
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9456 .- 1557-9662. ; 44:2, s. 316-317
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Tidskriftsartikel (refereegranskat)abstract
- A digital sampling wattmeter has been designed for calibration of power analyzers. The wattmeter is based on two commercially available sampling DVM's. The power spectrum is calculated with DFT analysis. High accuracy is achieved by phase locking and simultaneous sampling.
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| 12. |
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| 13. |
- Schon, K., et al.
(författare)
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Intercomparison on PD calibrators and PD instruments
- 1999
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Ingår i: IEE Conference Publication. - : Institute of Electrical and Electronics Engineers (IEEE). - 0852967195 ; , s. 1.5.S1-1.8.S1
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Konferensbidrag (refereegranskat)abstract
- Within the framework of a European project, two partial discharge calibrators were circulated to thirteen laboratories for an intercomparison of impulse charge measurements in the range between 1 pC and 500 pC. The deviations of the charge values q reported by the laboratories were, with a very few exceptions, within ±(0.1 pC+0.03·q). Furthermore, the characteristics of several partial discharge measuring instruments were investigated. The indication of some of the instruments showed deviations of more than ten percent from the correct values.
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