Electricity: measuring and testing – Impedance – admittance or other quantities representative of... – Lumped type parameters
Patent
1989-04-28
1993-11-16
Wieder, Kenneth A.
Electricity: measuring and testing
Impedance, admittance or other quantities representative of...
Lumped type parameters
324651, 324673, 324681, G01R 2728
Patent
active
052627306
ABSTRACT:
Measurements of the permittivity of samples over a very wide frequency range and a wide temperature range have previously involved such problems as changing parts of the measuring equipment in different regions of the frequency range, substituting one of the components of a bridge used as part of the equipment to obtain bridge balance, and limited permittivity resolution. The present invention employs a capacitance bridge formed by a sample held between electrodes, a series capacitor and a detector comprising a high input impedance amplifier and correlators. The bridge is balanced by applying voltages of known relative amplitude and phase constructed from outputs having relative phases of 0.degree., 90.degree. and 180.degree. of two phase-locked oscillators. The voltages are constructed using phase shifters, attenuators and summer-driver circuits. At low frequencies the applied voltages are obtained from a waveform synthesizer. In order to allow for any inaccuracies in the amplitude and phase of the applied voltages, a reference bridge is provided which comprises two capacitors connected in series and a detector which includes a high input impedance amplifier, connected between the junction of the capacitors and a common terminal.
REFERENCES:
patent: 4467271 (1984-08-01), Ruckenbauer
patent: 4481464 (1984-11-01), Noguchi
Edmonds, I. R., et al., "A Spectrometer for the Measurement of Complex Permittivity", Journal of Physics E: Scientific Instruments 1972, vol. 5, pp. 1067-1071.
Pratt, G. J., et al., "A Wide-band Bridge for the Measurement of the Complex Permittivity of Polymeric Solids and Other Materials", Journal of Physics E, 1982, vol. 15, pp. 927-933.
T. Furukawa et al., "Computer-Controlled Apparatus for Measuring Complex Elastic, Dielectric and Piezoelectric Constants of Polymer Films", vol. 57, No. 2, Feb. 1986, pp. 285-292.
A. Kakimoto et al., "Precise Measurement of Dielectric Properties of Frequencies from 1 kHz to 100 MHz", vol. 58, No. 2, Feb. 1987, pp. 269-275.
Pring Philip C. J.
Smith Michael J. A.
British Technology Group Ltd.
Solids Jose
Wieder Kenneth A.
LandOfFree
Apparatus and method for determining the permittivity of samples does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for determining the permittivity of samples, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for determining the permittivity of samples will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-24439