88150 - Measurement Instrumentation P

Learning outcomes

After successfully attending the Course, the student understands the basic analytical tools for the representation of physical quantities both in the time- and frequency-domain; knows and understands the operation of modern instrumentation, with particular emphasis to sampling-based instruments; is capable of achieving a deep insight of instrument specifications, and thus evaluating their actual performance in the application of interest and comparing different commercial instruments; knows the modern standards and methodologies for the evaluation and expression of the uncertainty of measurement; understands and is capable of applying the main algorithms for signal analysis in the frequency-domain; is capable of programming, in the framework of commercial software, the remote control both of single instruments and entire automated measurement set-ups.

Course contents

Frequency-Domain representation and analysis of signals and systems

Fourier series. Fourier transform and integral. The notion of bandwidth of a signal. Dirac operator. Transfer function and impulse response of a linear time-invariant system (LTI).  Amplitude and phase response of a LTI system. Properties and examples.

Analogue-to-Digital (A/D) Conversion 

Ideal A/D conversion: quantization and encoding. Quantization error. Classification of non-idealities in A/D conversion. Basic properties of stochastic processes and quantization noise. Model and effective bits for a real A/D Converter (ADC). Considerations on non-idealities and uncertainty. 

Digital Sampling Oscilloscope (DSO)

Instrument fundamentals, functional block diagram. Front-end circuits for the input signal conditioning. Analogue-to-digital acquisition channel: input impedance, sample/hold, A/D converter. Trigger circuit and methods. Time base. Real-time equally-spaced sampling, Shannon/Nyquist criterion. Ideal continuous-time reconstruction of the sampled signal and practical methods based on finite impulse response digital filters. Main parameters and specifications in DSO datasheets. Considerations on non-idealities and uncertainty.

Instrumentation and techniques for spectral analysis

Spectrum Analyzer (SA): multiple-conversion architectures, bandwidth, frequency resolution, dynamic range. Main operative parameters and related optimization for best measurement accuracy in the different applications. Analysis of commercial instruments. Digital spectral analysis: sampling-based techniques and DFT/FFT algorithms. Effects of finite time record and introduction to windowing. Considerations on non-idealities and uncertainty.

Readings/Bibliography

Slides and notes edited by the Teacher. Commercial component and instrumentation datasheets. User manuals.

Reference textbook: Testo di riferimento: M. Norgia, A. Pesatori, R. Ottoboni, C. Svelto, "Misure: dai fondamenti alla strumentazione," Esculapio.

Teaching methods

Class lectures.

Assessment methods

Oral exam.

Teaching tools

PC and digital projector. Measurement set-ups available at Department of Electrical, Electronic and Information Engineering "Guglielmo Marconi" - DEI.

Office hours

See the website of Gian Piero Gibiino