Page 507 - Instrumentation Reference Book 3E

490 Electrical measurements

V, = Vsin at

Lissajous figure

00

0” 30” 60” 90“

Q

120”
150’ 18b.
(C)
Vi” = Vi, -m
To x plates
sin
ut
of OscilloscoDe

ca Icu la ble Resultant Lissajous
phase figure when @ = O
shifter V2 out = V2 OUt sin (ut +e)
(d)
Figure 20.81 (continued) (c) phase measurement using Lissajous figures; (d) improved phase measurement using
Lissajous figures.
20.1 0 References Clarke, F. J. J. and J. R. Stockton, “Principles and
theory of wattmeters operating on the basis of regu-
Analog Devices, Data Acquisition Databook, Analog larly spaced sample pairs,” J. Pliys. E: Sei. Instrzrrn.,
Devices, Norwood, Mass., 10, 123-125 (1984) 15, 645-652 (1982)
Arbel, A. F., Analog Signal Processing and Instrunzenta- Dix, C. H., “Calculated performance of a digital sam-
tion, Cambridge University Press, Cambridge (1980) pling wattmeter using systematic sampling.” Prac.
Bailey, A. E. “Units and standards of measurement,’’ I.E.E., 129, Part A, No. 3, 172-175 (1982)
J. Phys. E: Sci. Znstr~rvz., 15, 849-856 (1982) Dix, C. H. and A. E. Bailey, “Electrical Standards of
Bishop, J. and E. Cohen, “Hall effect devices in power Measurement - Part 1 D. C. and low frequency stand-
measurement,” Electronic Engineeying (GB), 45, No. ards.” Proc. I.E.E., 122, 1018-1036 (1975)
548, 57-61 (1973) Fantom, A. E., Microwave Power Measurenzent, Peter
British Standards Institution, BS 3938: 1973: Specifica- Peregrinus for the IEE, Hitchin (1985)
tion for Current Transformers, BSI, London (1973) Froelich. M., “The influence of the pH value of
British Standards Institution, BS 3941: 1974: Spec$ica- the electrolyte on the e.m.f. stability of the
tion for Voltage Transformers, BSI. London (1974) international Weston cell,” Metrologia, 10, 35-39
British Standards Institution, BS 89: 1977: Specification (1974)
for Direct Acting Electrical Measuring bistrirments Goldman, D. T. and R. J. Bell, SI: The Iriternational
and their rlccessories, BSI. London (1977) Systenz qf Units, HMSO, London (1982)
Brodie, B., “A 160ppm digital voltmeter for use in ac Golding, E. W. and F. C. Widdis. Electrical Measwe-
calibration,” Electronic Engineering (GB), 56. No. nzents and Measuring Instrunients, 5th ed., Pitman,
693, 53-59 (1984) London (1963)