# Measurements

## Course description

a) Metrology systems (quantities, international system of units SI, definitions and realization of etalons of physical quantities, dissemination, traceability, calibration, conformity assessment);

b) Fundamental principles of measurement and information content of signals, mathematical model of the measurement system measurement scales, measurement strategies;

c) Measuring accuracy and uncertainty (absolute and relative errors, measurement result, true value, statistic analysis, measurement uncertainty), signal conditioning;

d) Measurement of electrical quantities (voltage, current, power, resistance, capacitance, inductance, frequency, phase, power factor, frequency spectrum, …);

e) Application of basic measuring instrumentation (ammeter, voltmeter, wattmeter, oscilosscope, vector analyser);

f) Measurement of non-electrical quantities (temperature, humidity, preasure, force, lenght, noise, …).

## Objectives and competences

The course introduce basic knowledge of metrology and measurements of technical quantities. Objectives of the course are:

a) to study the fundamentals of metrology and metrological systems, Si units, connections with other fields of science;

b) to introduce the basic principles of measurement of most important quantities in engineering, properties of measurement signals;

c) to learn the approaches and methods of measurement of basic electric quantities and caracteristics of measurement transducers;

d) to extend the concepts of measurement and comprehension and interpretation of the measurement results;

e) to study the meaning of statistic and analysis of measurement uncertainty;

f) to prepare for laboratory practices and work;

g) to learn the security requirements and protection when using measurement instrumentation in connection with power supply.

## Learning and teaching methods

Lectures, laboratory tutorials, solving practical tasks (problems).

## Intended learning outcomes

After successful completion of the course, students should be able to:

a) recognize measurements as basic discipline for acquisition and evaluation of information;

b) distinguish the basics of metrology and metrology systems;

c) choose the proper methods to measure basic electromagnetic quantities;

d) design the input stages of measurement systems for signal conditioning;

e) use the basic measuring instrumentation (ammeter, voltmeter, oscilloscope, ..);

f) evaluate the measurement results using statistic methods and their influence on measurement uncertainty;

g) know how to evaluate and interpret measurement accuracy and uncertainty in measurement result.

## Reference nosilca

1. Agrež D., "Weighted multi-point interpolated DFT to improve amplitude estimation of multi-frequency signal", IEEE Transactions on Instrumentation and Measurement, 2002, vol. 51, no. 2., pp. 287-292.
2. Štremfelj J., Agrež D., "'Nonparametric estimation of power quantities in the frequency domain using Rife-Vincent windows", IEEE Transactions on Instrumentation and Measurement, 2013, vol. 62, no. 8, pp. 2171-2184.
3. Beguš S., Bojkovski J., Drnovšek J., Geršak G., "Magnetic effects on thermocouples", Measurement science & technology, 2014, vol. 3, no. 25, pp. 1-11.
4. Žužek V., Batagelj V., Drnovšek J., Bojkovski J., "Effect of bushings in thermometric fixed-point cells", Measurement, 2016,  vol. 78, pp. 289-295.
5. D. Agrež, "A/D Conversion with Non-uniform Differential Quantization", Design, Modeling and Testing of Data Converters, P.Carbone et all (eds.), pub. by Springer-Verlag Berlin Heidelberg, 2014, pp. 277-306.

## Study materials

1. Dunn P.F., Measurement and Data Analysis for Engineering and Science, Second Edition, CRC Press, 2010.

2. Morris A.S., Measurement and Instrumentation Principles, Third Edition, Oxford: Butterworth-Heinemann, 2010.

3. Agrež D. in ostali, Meritve – laboratorijski praktikum (ver. 3), University of Ljubljana, Faculty of Electrical Engineering, 2013.

4. G. Geršak in ostali, Metrologija, University of Ljubljana, Faculty of Electrical Engineering, 2012.

5. Tumanski S., Principles of Electrical Measurement, Taylor & Francis, CRC Press, 2006.

6. Evaluation of measurement data – Guide to the expression of uncertainty in measurement International Joint Committee for Guides in Metrology, 2008, (http://www.bipm.org/en/publications/guides/gum.html).

## Bodi na tekočem

Univerza v Ljubljani, Fakulteta za elektrotehniko, Tržaška cesta 25, 1000 Ljubljana