Instrumentação e Medidas

Objectives

Familiarize students with generic electronic instruments used in laboratories. Basic knowledge of metrology concepts. Develop the expertise to project, automatic measuring systems based on acquisition systems and remote control of instrumentation devices.

Syllabus

Fundamentals of Instrumentation and Measurements. International Metrology System. Uncertainty in Measurement. Units and Standards. Basic modules for instrumentation: Operational Amplifiers. Basic circuits and limitations. Instrumentation amplifiers. Isolation amplifiers. RMS converters. Analog multiplier. Heterodyning. AD and DA converters. Data Acquisition Systems. Signal sampling. Parameter estimation. Measuring Instruments. Function generator. Oscilloscope. Spectrum Analyzer. Lock-in amplifier. Power supplies. Measurement of electrical quantities. Voltage, current, power, energy, resistance and impedance. Transducers. Signal Conditioning. Linearization. Force and position transducers. Virtual Instruments and Automated Measuring Systems. Basic Concepts. Standards for communication protocols. Acquisition Systems. Instruments and programs.

Prerequisites

Circuit Analysis

Cross Competence Component

Team work. The assessment percentage associated with this competence should be around 10%.

Laboratorial Component

The laboratory sessions are 3 hours per week. In week 1, the students perform a non-evaluated session of introduction to the laboratory instruments. The evaluated part consists of four assignments, where the first two are done in weeks 2 and 3 (with 1 laboratory session for each work with a 15% weight on the final laboratory grade). The last two assignments are done in weeks 4 through 7 (with 2 laboratory sessions for each and a 35% weight on the final laboratory grade). The assignments require previous preparation e end with the delivery, in the end of corresponding session, of a form filled out with the obtained results and conclusions.

Programming And Computing Component

This course includes, in the laboratory assignments, a MATLAB component in which the students configure a data acquisition board to acquire multiple input voltages and perform signal processing to estimate several parameters from the input voltages (average value, RMS value, frequency and spectrum). MATLAB is also used to remotely control instruments using IEEE 488.2 interface. LabVIEW is taught for data acquisition, instrument control and signal processing.

Ethical Principles

All members of a group are responsible for the group’s work In any assessment, every student shall honestly disclose any help received and sources used. In an oral assessment, every student shall be able to present and answer questions about the entire assignment and solution.