IN/0021 - ELECTRICAL AND ELECTRONIC MEASUREMENTS
Academic Year 2021/2022
Free text for the University
CARLO MUSCAS (Tit.)
- Teaching style
- Lingua Insegnamento
|[70/89] ELECTRICAL, ELECTRONIC AND COMPUTER ENGINEERING||[89/10 - Ord. 2016] ELETTRICA||9||90|
|[70/89] ELECTRICAL, ELECTRONIC AND COMPUTER ENGINEERING||[89/20 - Ord. 2016] ELETTRONICA||9||90|
|[70/89] ELECTRICAL, ELECTRONIC AND COMPUTER ENGINEERING||[89/30 - Ord. 2016] INFORMATICA||9||90|
The Course aims at providing basic knowledge in the field of Electrical and Electronic Measurements and introduce modern measurement equipment, signal conditioning and digital instruments. Continuous learning is favored by means of technical literature, manuals of manufacturers, technical standards and the law.
More in detail, the educational goals of the course can be expressed through the following five descriptors:
- knowledge and understanding
knowledge and understanding of the fundamental theoretical and practical aspects of the electrical and electronic measurements, with particular focus on digital instruments.
- applying knowledge and understanding
Capability to understand the performance of the basic instrumentation and to choose measurement instruments according to technical and economic considerations. Awareness of the safety aspects in the use of measurement systems.
- making judgements
Capability to correctly interpret the results provided by a measurement system, according to the characteristics of its components. Capability to manage the results, by also assessing the possible risks arising, for instance, from the use of non-traceable instruments.
- Communication skills
Capability to communicate technical information and to discuss problems and solutions with specialists and non-specialists.
- Learning skills
Capability of continuous learning, through the proper interpretation of scientific and technical literature, manuals of manufacturers and technical standards.
The knowledge of theory of electric circuits is required (in particular the following subjects: lumped circuits, steady state circuits, circuits in sinusoidal regime, filters, circuit analysis in dynamic operation). Basic concepts of system analysis are also suggested.
Introduction (2 hours)
Introduction to the course and to its specific educational goals. Description of teaching material and of exam tests.
Fundamental concepts of measurements (10 hours)
Fundamental elements of a measurement. Measurement Errors. Errors in direct and indirect measurements. Measurement traceability. International metrology organization. The International System of measurement units. Measurement uncertainty. Elements of statistics and probability. Type A and Type B uncertainty evaluation. Uncertainty propagation Expanded uncertainty. Compliance tests.
Basic electrical measurements (4 hours)
Measurement of DC voltages and currents. Load and insertion effects. Measurement of AC quantities. Root Mean Square (RMS) and power.
Analog signal processing. (3 hours)
Circuits with operational amplifiers. Signal conditioning. Rectifiers. True RMS converters.
AD and DA Conversion (8 hours)
Sampling and quantization. Input-Output diagrams. Quantization noise. Weighted network and R/2R DA converters. Dual ramp, successive approximations, flash and pipeline AD converters. Sample & hold. Specifications of AD and DA converters.
Digital multimeters (4 hours)
Block diagram. Measurement of voltage, current and resistance. Specifications of multimeters.
Data acquisition systems (6 hours)
Single-channel and multi-channels systems. Communication between instruments and computers. Virtual Instrumentation.
Analog oscilloscope (4 hours )
Cathode ray tube. Vertical channel and time basis. The trigger. Dual trace oscilloscopes Voltage probes.
Digital oscilloscope (4 hours )
Operation and performance. Real-time and equivalent-time sampling.
Time and frequency measurements (4 ore)
Circuits for time and frequency measurements. Universal counter. Binary and BCD counter. Errors in time and frequency measurements.
Analysis in the frequency domain (10 hours )
Sampling theorem and aliasing. Signal truncation and spectral leakage. The Discrete Fourier Transform and its practical aspects in measurement systems. Super-heterodyne spectrum analyzers. FFT spectrum analyzers.
Differential input circuits (2 hours)
Differential amplifier. Instrumentation amplifier.
Disturbances in electronic measurements (5 hours)
Common and ground connections. Inductive and capacitive coupling. Shields. Measurement noise.
Laboratory and experimental work (24 hours)
E1 - Uncertainty analysis. ISO GUM Standard. Data series analysis. Statistical parameters evaluation. Presentation of results: significant digits.
E2 - Digital multimeter. Alternating and continuous voltage measurement. Frequency spanning. Resistance measurement (2wire and 4wire set up). Frequency behavior.
E3 - Oscilloscope. Probe compensation. Voltage and current characteristic evaluation in electric bipole. Example for rectifier diode. Use of a digital storage oscilloscope. Acquisition of transient events.
E4 - Virtual Instruments. Introduction to virtual instruments.
E5 - Data acquisition systems. Use of data acquisition boards. Analysis and performance of basic Virtual Instruments (VI).
E6 - Analysis of signals in the frequency domain. Virtual instruments for frequency analysis. Practical aspects of sampling and signal truncation. Observation windows.
The course has an overall duration of 90 hours. 66 hours consist of lessons and classroom exercises, during which the teacher presents the subjects indicated in the program and discusses some numerical examples. The remaining 24 hours involve experimental work in the laboratory, where the students, supervised by the teacher, use the basic measurement instrumentation (multimeters, oscilloscopes, data acquisition boards managed through virtual instruments).
Different teaching methods could be adopted, according to the provisions that will be given by the University.
Verification of learning
The acquisition of the learning outcomes is verified through a single oral exam, during which students are asked to discuss some of the topics covered in the course, possibly with the help of simple numerical examples.
The score of the examination is provided by a grade out of thirty. To pass the exam, thus reporting a mark of not less than 18/30, the student must demonstrate a basic knowledge of all the topics discussed. To achieve a score of 30/30 with honors, the student must demonstrate an excellent knowledge of the topics discussed.
The assessment takes into account the capacity of both present with rigor and effectiveness the theoretical subjects and highlight their practical aspects.
1. Notes of the teacher, available at: https://www.unica.it/unica/it/ateneo_s07_ss01_sss03.page?contentId=SHD30592
2. M. Savino: Fondamenti di scienza delle misure. Nuova Italia Scientifica, 1992
3. U. Pisani: Misure Elettroniche. POLITEKO Edizioni, 1999
4. G. Iuculano, D. Mirri: Misure Elettroniche. CEDAM, 2002
Supplementary teaching material (slides used in some in-depth lessons, exercises, data from manuals and catalogs) is available on https://www.unica.it/unica/it/ateneo_s07_ss01_sss03.page?contentId=SHD30592