NBS phase angle calibration standard

Turgel, R. S.

doi:10.6028/nbs.tn.1144

Cited by 7 publications

(29 citation statements)

References 1 publication

(3 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The accuracy of the auto-zero correction, as well as the linearity data, were checked experimentally using a 1800 bridge method described in more detail in [3]. IM-34, NO.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…The accuracy of the auto-zero correction, as well as the linearity data, were checked experimentally using a 1800 bridge method described in more detail in [3]. As an example of the calibrations of a commercial phase meter that can be easily carried out using the Phase Angle Calibration Standard, Fig.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…The circuit, as well as the auto-zero measurement procedure, has been designed to minimize the effect of internal errors in the phase detector. A more detailed description can be found in [3].…”

Section: Auto-zero Correctionmentioning

confidence: 99%

See 2 more Smart Citations

A Precision Phase Angle Calibration Standard for Frequencies up to 50 kHz

Turgel

1985

IEEE Trans. Instrum. Meas.

View full text Add to dashboard Cite

As a numerical example let a = 10°, VFS = 10.24 V, M = 12, and Vp = 1 V; this leads to 4e2(max) = 0.072°. In order to reduce this error we should increase M and Vp, and decrease a. Table II illustrates the change of a/sin a with et. It is obvious that we have to choose a reasonably high sampling frequency which is at least, say, four times the signal frequency. IV. OVERALL ERRORThe phase error due to mislocating a single zero-crossing is +± 4eI ± 0ke2 However, the overall error ke is due to mislocating the two zero-crossings of the signals x(t) and y(t), and is given by =e = ± Oelx ± Oe2x ± + ely ± ¢e2y (16) From the previous analysis it is obvious that kei of Table I has a double hump shape in the range 0 < 0 c a, whereas Oe2 is maximal when 0 = 0 or a. Consequently, the overall worst-case Oe is not the sum of the worst-case 4)el and ke2, but depends on the various parameters involved.V. CONCLUSIONS Calculating the phase difference between two signals, using synchronous real-time sampling, has been proposed. The method is based on linear interpolation, which gives the least measurement accuracy. It was shown that this accuracy can be improved by increasing the sampling frequency, the signal amplitudes, and the number of A/D quantization levels. However, more accurate results are expected if we resort to computer-based nonlinear interpolation, since the sampled values can be fitted into a sinusoidal function.ACKNOWLEDGMENT As a first author, I would like to present the research of my life to the memory of my mother, Hekmat Mahmoud Fawzy, who passed away in Cairo, Egypt, on December 13, 1984, during the preparation of this paper. Exceptional signal stability and rapid response when changing operating parameters can be achieved by using a method of digital waveform generation for the analog output [1]. With this method two sets of calculated values, representing sample points at equal time intervals along two waveforms, are converted to voltages using dual-channel analog-to-digital converters. The resulting stepped sine waves (see Fig. 1 Even though converter characteristics depart from the ideal, the spectral purity of the output sine wave can be made relatively high by using a reasonable large number of sample points per waveform. The lower limit of the harmonic content, assuming that the sampling harmonics have been filtered out, is given by the quantization noise which for an ideal 16-bit converter is -97.8 dB, and -73.8 dB for a 12-bit converter [4]. Fig. 3 shows measured spectra for 50/60 kHz using 16-bit conversion. The quantization noise is more evident for the 12-bit conversion at 50 kHz and appears in the form of larger harmonics (Fig. 4). The measured harmonic components, which are above the theoretical limit, are attributed to imperfect converter and amplifier characteristics. pling rate, resolution is traded for conversion speed with faster 12-bit converters in place of the 16-bit converters used at lower frequencies. Active low-pass filters with a corner frequency of approximately 0.35 MHz reduce...

show abstract

“…The accuracy of the auto-zero correction, as well as the linearity data, were checked experimentally using a 1800 bridge method described in more detail in [3]. IM-34, NO.…”

Section: Experimental Methodsmentioning

confidence: 99%

Section: Experimental Methodsmentioning

confidence: 99%

See 1 more Smart Citation

A Precision Phase Angle Calibration Standard for Frequencies up to 50 kHz

Turgel

1985

IEEE Trans. Instrum. Meas.

View full text Add to dashboard Cite

show abstract

“…With increased frequency, all of the effects are more pronounced. A fuller discussion is given in [2] and [4]. Specifications shown in table I are based on experimentally determined accuracies of the three prototype phase standards built at NBS.…”

Section: Accuracymentioning

confidence: 99%

Phase meter calibration at NBS

Turgel¹

1988

J. RES. NATL. BUR. STAN.

View full text Add to dashboard Cite

To provide a phase meter calibration service, a phase angle calibration standard has been developed at NBS. This standard is a signal. generator with two sinusoidal outputs and uses direct digital synthesis to generate the signals. The phase angle between the two sinusoids is determined by the input parameters in the calculation of the sets of digital values from which the analog output is synthesized. An auto-zero compensation mode corrects for residual phase differences in the two output channels. The phase resolution is better than 0.002' over a frequency range from 2 Hz to 5 kHz and 0.005' from 5 to 50 kHz. Phase meter calibration data are fitted to a linear model from which appropriate corrections for the phase meter readings can be derived. Statistical treatment of the data provides an estimate of the uncertainty of the corrected phase meter readings relative to the phase angle calibration standard.

show abstract

“…The J Bureau's overall goal is to strengthen and advance the nation's science and technology and facilitate their effective application for public benefit. To this end, the Bureau conducts research and provides: (1) a basis for the nation's physical measurement system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau's technical work is performed by the National Measurement Laboratory, the National Engineering Laboratory, the Institute for Computer Sciences and Technology, and the Institute for Materials Science and Engineering .…”

mentioning

confidence: 99%

NBS 50 kHz phase angle calibraion standard

Turgel¹

1986

Self Cite

View full text Add to dashboard Cite

NBS phase angle calibration standard

Cited by 7 publications

References 1 publication

A Precision Phase Angle Calibration Standard for Frequencies up to 50 kHz

A Precision Phase Angle Calibration Standard for Frequencies up to 50 kHz

Phase meter calibration at NBS

NBS 50 kHz phase angle calibraion standard

Contact Info

Product

Resources

About