1,720,998 research outputs found
Using High-Precision Multimeter Digitizer for High Short-Circuit Current Calibration
No full textThe calibration of transient current sensors is
fundamental for the reliability of high currents short-circuit
tests. The test can be performed with prospective or withstand
current, and in both cases, the dynamic behavior of the current
sensors has to be investigated, due to their influence on the scale
factor (SF) value. The requirements of the IEC 62475 standard
can be achieved with a calibration in transient conditions,
performed with an approved reference measuring system. In this
paper, a more accurate measuring system is presented, for the
improvement of the Istituto Nazionale di Ricerca Metrologica
high transient current measuring capability. The result is
achieved by analyzing the performance in digitalization of a
commercial Keysight (former Agilent) multimeter 3458A, with a
custom algorithm that can also perform the calculation of Joule
integral (I2 t ) on a given amount of time along the acquired signal.
The objective of the research is the realization of a measurement
system with an uncertainty compatible with the test laboratory
requirements, both for the determination of SF and evaluation of
the performance in the measurement of I2 t in the device under
calibration
Giant Magnetostrictive materials: from the dynamic characterization to the high speed tracking
No full text
Improvement of the INRiM calibration capabilities for lightning impulse voltages from 200 kV to 600 kV
Get PDFIn this paper, an improvement of the calibration measurement capabilities (CMCs) of the Istituto Nazionale di
Ricerca Metrologica (INRiM) for measurements of Lightning impulse (LI) voltages from 200 kV to 600 kV, is proposed. This improvement is the result of a more detailed characterization of the INRiM measurement system for LI measurements. The INRiM LI measurements of the most critical waveforms at voltages up to 600 kV for the EURAMET.EM-S42 comparison were submitted to a refinement with a discrete deconvolution method. The comparison results were then recalculated by inserting the INRiM measurements, both with and without deconvolution, (the latter for less critical waveforms) and the updated uncertainties. The INRiM measurements after recalculation were still in agreement with the comparison reference value, even for short impulses (0.84 μs), where the size of the used divider was not optimal. The recalculation did not affect the degrees of equivalence of the other participants and the consistency of the comparison. The new INRiM uncertainties range from 0.5 % of Ut (test voltage) for the long impulse at 600 kV to 2 % of T1 (front time of the impulse) for the short impulse at 400 kV and 600 kV. A validation of both the new uncertainties and the selected discrete application of deconvolution is also proposed, together with a verification of the compliance of the INRIM measurement system up to 600 kV with the requirements of a reference system
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