Course code CTU01
Course title Metrology of Electrical Quantities
Institution Czech Technical University in Prague
Course address Czech Technical University, Faculty of Electrical Engineering, Technická 2, CZ-166 27 Prague 6, Czech Republic
City Prague
Minimum year of study 4th year
Minimum level of English Good
Minimum level of French None
Key words Metrology, calibration, standards of electrical quantities, ratio devices, measurement methods, measurement uncertainties.
Language English
Professor responsible Jaroslav BOHACEK
Telephone (4202) 2435 2220
Fax (4202) 3333 9929
Email bohacek@feld.cvut.cz
Participating professors
Number of places Minimum: 10, Maximum: 20, Reserved for local students: 0
Objectives To present an overview of modern and perspective methods for precision measurements of electrical quantities, to demonstrate various techniques used in calibrations of electrical measurement instruments and standards.
After a brief introduction devoted to problems of legal metrology and to realization, conservation and reproduction of measurement units by means of measurement standards, explanation is focussed on facilities and methods for precision measurements of electrical quantities. Considerable attention is paid to inductive ratio devices and their metrological employment. Possibilities of application of nuclear magnetic resonance, Josephson arrays and quantum Hall effect devices to precision measurements of current, voltage, resistance and capacitance are discussed.
Programme to be followed "Five 3-hour lectures:

1.Legal metrology and its role. ""Convention du Metre"". Measurement units and measurement standards.
2.Quantum standards of voltage and resistance. Thompson-Lampard's capacitance standard. Transfer standards.
3.Voltage and current inductive ratio devices and optimization of their metrological parameters.
4.Methods for precision measurement of dc current and dc voltage. Modern potentiometers. Measurements of voltage, power and energy in audiofrequency range.
5.Bridges for dc and ac measurements of resistance. Transformer and current-comparator-based capacitance bridges. Metrological applications of the quantum Hall effect (QHE).

Five 2-hour laboratory demonstrations:
1. Thompson-Lampard's capacitance standard.
2. Frequency performance of resistance standards.
3. Calibration of capacitance boxes.
4. Calibration of inductive voltage dividers.
5. Discussion of results.

4-hour visit to the Czech Metrology Institute:
Calibration of digital multimeters, QHE-based calibrations of resistance standards."
Prerequisites Basic knowledge of applied physics.
Course exam Continuous evaluation through laboratory exercises and an evaluation test at the end of the course.
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