Instrumentation and Measurement

Instance: 2024/2025 - 2S

Cycles of Study/Courses

Last updated on 2025-02-20.

Fields changed: Objectives, Resultados de aprendizagem e competências, Métodos de ensino e atividades de aprendizagem, Fórmula de cálculo da classificação final, Provas e trabalhos especiais, Avaliação especial, Bibliografia Complementar, Obtenção de frequência, Programa, Trabalho de estágio/projeto, Software de apoio à Unidade Curricular, Componentes de Avaliação e Ocupação, Palavras Chave, Melhoria de classificação

Teaching language

Objectives

The objective of the Instrumentation and Measurement course is twofold. First, it provides students with a comprehensive understanding of measurement principles and their application in engineering, developing fundamental skills for the proper measurement of electrical signal parameters and physical quantities. Second, it provides students with the necessary tools and knowledge to design and implement effective data acquisition solutions for precision measurement systems.

To some extent, a key goal is to establish measurement quality assessment as a standard practice in the presentation of experimental results. This includes applying uncertainty parameters from operation manuals whenever certified instruments are used. The objective is to instill good measurement practices by systematically quantifying the associated uncertainties, thereby fostering analytical thinking and rigor in the presentation of experimental results. Additionally, a paradigm shift is proposed, i.e. students transition from a user-oriented perspective to that of a designer, where circuit design techniques are introduced for the development and implementation of measurement instruments. This pedagogical approach provides students with invaluable insights into the intrinsic sources of uncertainty introduced by the electronic circuits that make up these instruments, as well as the methods for mitigating them, both during the design phase and in operation.

In short, the idea is to raise awareness of the fact that the result of a measurement is only meaningful when accompanied by its associated uncertainty, and to equip students with the necessary prerequesites for this analysis. Additionally, the course seeks to deepen understanding of the most suitable measurement architectures for each type of measurand, identify sources of uncertainty in these circuits, examine their propagation, and assess their impact on the final result.

Learning outcomes and competences

Learning outcomes in this Curricular Unit are assessed by the ability to:

• Analyze and explain the operating principles of electronic devices in typical measurement and instrumentation settings;
• Properly use electronic instrumentation in experimental measurements of electrical quantities and signals, recognizing and evaluating possible sources of error;
• Apply knowledge of transducers and instruments for measuring non-electrical quantities;
• Interpret key specifications of circuits and components in the measurement chain;
• Characterize a measurement problem and prepare requirements and technical specifications;
• Conceptualize, design, implement, and validate measurement systems and instrumentation for specific applications;
• Organize, prepare and present technical documentation related to a method or instrument and apply methods for evaluating the quality of measurements.

To achieve the above goal, students should develop the skills outlined below.

• Specific technical skills:
• Master technical concepts of measurement and instrumentation;
• Develop reasoning skills to analyze and solve measurement problems systematically and accurately;
• Develop skills in designing, implementing, and testing instrumentation for specific applications.
• Other skills:
• Develop experimental teamwork skills through laboratory and project work;
• Develop the ability to interpret and apply technical data from component datasheets in design and troubleshooting;
• Develop written and oral communication skills with technical rigor.

Working method

Pre-requirements (prior knowledge) and co-requirements (common knowledge)

Basic knowledge of electrical circuit analysis and fundamental electronics.

Program

The curriculum is structured into the following four primary components.

• Part I. Measurement and Uncertainty

This first component focuses on the fundamental errors inherent in any measurement, emphasizing their statistical randomness. It introduces the concept of "uncertainty'" and its critical role in engineering applications. Measurement and uncertainty are presented as an inseparable action-reaction relationship, providing students with tools to systematically apply in the analysis of uncertainty in laboratory experiments. This approach promotes awareness of measurement limitations and encourages critical interpretation of data.

• Historical Perspective of Metrology
• International System of Units (SI)
• Metrological Concepts and Terminologies
• Measurement Quality

• Part II. Signal and Data Acquisition Chain

This second, and largest, component provides a comprehensive foundation in the process of capturing, conditioning, and converting electrical signals into digital data. It encompasses the fundamental building blocks of data acquisition systems. These include analog circuitry for input interfaces, signal conditioning circuits, analog-to-digital converters (ADCs), and digital signal processing techniques. Emphasis is placed on the performance characteristics of ADCs, such as resolution, sampling rate, quantization noise, architecture, as well as the impact of aliasing and the importance of anti-aliasing filters. Additionally, this component aims to provide students with a profound comprehension of essential analog circuits employed in instrumentation, such as operational and instrumentation amplifiers, filters, multiplexers, and digital interfaces, with special attention given to the design considerations of precision instrumentation amplifiers, noise reduction techniques, electrical isolation methods, and other signal integrity issues.

• Introduction to Electrical Signals
• Signal Acquisition
• Sampling and reconstruction of signals
• Spectral overlapping (aliasing)
• Quantization, quantization error, encoding
• ADC performance characterization
• Digital-to-Analog Converter Architectures
• Analog-to-Digital Converter Architectures
• Signal Conditioning
• Fundamental circuit configurations
• Instrumentation amplifiers
• Specialized amplifiers / applications
• Active analog filters
• Electronic noise
• Electromagnetic compatibility

• Part III. Electronic Instrumentation

Moving from the basic principles of signal conditioning to the measurement context, this section focuses on the study of digital instruments typically used to measure electrical quantities. These instruments include, but are not limited to, multimeters for measuring voltage, resistance, and other electrical properties, as well as waveform analyzers such as oscilloscopes, which are used to measure signal characteristics like peak-to-peak and RMS values of periodic voltage signals. The goal is to explore these instruments in depth, emphasizing their operating principles, design considerations, and measurement capabilities. As a result, students will gain a deeper understanding of how to operate these instruments effectively and obtain circuit references for future designs.

• Digital Multimeter
• Power and Energy Meters
• Oscilloscopes
• Digital Counters
• Impedance Meters

• Part IV. Sensors, Transducers and Measurement Systems

This section covers the measurement of non-electrical quantities and introduces a wide range of transducers. These are studied in detail with respect to the underlying physical mechanisms. In addition, the application of such devices is explored through the study of appropriate electronic circuit interfaces and the proper conditioning for each transducer.

• Transducer Devices
• Thermoresistive, Thermoelectric, Electromechanical, Photoelectric, Electromagnetic. Electrochemical
• Digital Communication with Transducers
• Examples of Complete System/Circuit Designs: From the Transducer to Digital Display

Mandatory literature

Teaching methods and learning activities

The teaching methods and learning activities in this course combine theoretical instruction with direct practical application. This approach allows for a solid understanding of the fundamental concepts by carrying out practical experiments that emphasize the application of measurement techniques and the design of various measurement systems, both for electrical and non-electrical quantities.

In the Measurement component, lectures provide a structured foundation that introduces the basic principles, metrological standards and analytical methods needed to take accurate measurements and interpret data. In the Instrumentation component, the operating principles of measurement systems and the most common types of electronic circuits are studied, delving into implementation details and introducing examples of practical application in the context of engineering. Interactivity with the students is promoted in all topics, particularly those related to the limitations and common problems of the various practical implementations. In the form of an open discussion, students are challenged to analyze the most typical solutions, thus promoting critical thinking about the details of the topics covered.

Practical classes are designed to complement and reinforce the theoretical framework by involving students in experimental procedures using laboratory equipment. Through these practical activities, students develop essential skills in calibration, data acquisition and uncertainty analysis with laboratory instrumentation. Students also participate collaboratively in various measurement system implementation projects, working on the design and execution of experiments, the interpretation of results and the critical evaluation of measurement limitations. This balanced approach equips students with the knowledge and technical skills required for effective application in engineering and research. The effectiveness of the integration of theory and practical experimentation is assessed through various practical assessment sessions in class with the instructor, the production of technical documentation by the students and the oral presentation of the work to their peers.

Software

keywords

Evaluation Type

Assessment Components

Amount of time allocated to each course unit

Eligibility for exams

Attendance in laboratory classes is mandatory and subject to the maximum number of absences allowed.

The justification of a class absence does not eliminate the respective work from the count for the purpose of classification.

Students who have attended laboratory classes in previous academic years may keep that classification component. This option is automatically granted if the student does not enroll in a laboratory class. Otherwise, the previous laboratory classification will be permanently canceled.

Calculation formula of final grade

The final classification (C) out of 20 is determined as follows:

C = 0.40 × E + 0.60 × min{ P, E + 4 }

where:

• E is the exam grade (out of 20.0);
• P corresponds to the total laboratory score (out of 20.0);

with P determined by:

P = 0.15 × ( LAB₁ + LAB₂ ) + 0.35 × ( PRJ₁ + PRJ₂ )

in which:

• LAB₁ and LAB₂ correspond to the evaluation results (out of 20.0 each) of the first and second parts of the proposed laboratory work, covering measurements / uncertainties and transducers, respectively;
• PRJ₁ and PRJ₂ are the classifications (out of 20.0 each) obtained in the two projects.

Examinations or Special Assignments

The initial laboratory classes focus on proper circuit implementation on a test board and the application of appropriate measurement techniques. Students are evaluated as they progress through these classes, culminating in an oral evaluation of each member of the group, which includes a set of test procedures to be performed. This evaluation component is referred to as LAB₁.

The final laboratory classes are dedicated to communicating with transducers through digital interfaces. The development of student work during these classes and their experimental demonstrations are the target of the evaluation indicated as LAB₂.

Internship work/project

In the laboratory classes, two projects (namely PRJ₁ and PRJ₂) will be carried out involving the implementation of complete measurement chains.

PRJ₁ concludes with the submission of a technical datasheet containing all relevant specifications and performance metrics of the work developed by each student group.

PRJ₂ concludes with an oral class presentation of the work.

The PRJ₁ and PRJ₂ evaluations are not limited to the deliverables required for each of these projects, but also cover the work done and individual performance demonstrated by students in the classroom.

Special assessment (TE, DA, ...)

All students are required to perform the proposed laboratory work, including students with special status.

Students with special status are subject to the same evaluations as other regular students.

Classification improvement

Theoretical component: by means of an examination held during the period provided for this purpose.

Practical component: by performing all laboratory activities in the following academic year, with mandatory enrollment in a laboratorial class.

Observations

Any practices detected and identified as fraudulent or improper that violate the provisions of the "Ethical Code of Academic Conduct for the University of Porto" will be reported.