Learning objectives
Knowledge and ability to understand: Through the front lessons held during the course, the student will acquire the methods and knowledge necessary to understand the working principles, the performances of the measuring instruments and their application fields.
Ability to apply knowledge and understanding:
Through practical classroom exercises, students learn how to apply knowledge acquired in a real context of design, as well as in multidisciplinary or non-familiar areas.
Judgment autonomy:
The student must be able to understand and evaluate critically the operation and performance of the various instruments / systems / measurement chains in order to identify the most appropriate application solutions.
Communication skills:
Through lectures and discussion with the lecturer, the student acquires the specific vocabulary inherent to the world of measurement. It is expected that, at the end of the course, the student will be able to convey, in oral and written form, the main course content such as ideas, engineering problems and their solutions.
Learning ability:
The student who has attended the course will be able to deepen his or her knowledge of metrology and sensor technology, even outside the topics covered in class, in order to deal effectively with problems in the world of work or undertake further training.
Prerequisites
Course unit content
The course aims to provide students with general criteria for the selection and implementation of measuring systems. It starts with basic metrology and the static performance of measuring instruments and then addresses the main types of sensors used in industrial plant and automation.
Full programme
Introduction to Metrology. Measurement process. Intensive and extensive quantities. Measurement methods: deviation/zeroing, direct/indirect. Measurement model. Expression of a measurement. Significant digits. Error and uncertainty. Compatibility of measurements. International System of measurement units. Evaluation of uncertainty according to GUM (Guide to the expression of Uncertainty in Measurement). Standard uncertainty (Type A or B), combined uncertainty, extended uncertainty. Monte Carlo Methods for the estimation of uncertainty. Elements of statistics. Static calibration and static properties of measurement instruments. Dynamic properties of measurement instruments. Simple signals and sinusoids. Transfer function. Fourier analysis and frequency domain. Dynamic calibration. Zero order systems, first order systems, second order systems. Acquisition chain of signals. Analog-to-digital conversion. Sampling of signals and aliasing. Quantization of a signal. Filters (ideal and real) and their transfer functions. Configuration of system for single channel and multiple channel acquisition. Trigger: characteristic parameters and its use in the acquisition process. Elements of temperature scales (relative and absolute). Temperature measurements. Thermal expansion methods (bimetallics, liquid-in-glass, pressure). Thermocopules, electrical-resistance sensors, thermistors. Fundamentals of thermal radiation. Broadband radiation thermometers (Pyrometers). Relative displacement sensors. Resistive potentiometers, LVDT, optical encoders (incremental and absolute), capacitance pickups, eddy-current transducers, laser triangulation sensor. Seismic sensors: seismometer and accelerometers. Piezoelectric accelerometers. Strain measuements. Definition of stress and strain in mono-axial case. Resistance strain gauges. Rosette strain gauges. Application of strain gauges. Wheatstoone bridge. Applications: normal stress and bending stress. Temperature effects on strain gauges. Force measurements. Basic methods of force measurements. Elastic force transducers. Bonded strain gauge transducers (load cells): compression, bending and torque. Piezoelectric load cells. Impact hammer with load cell. Pressure measurements. Definition of relative and absolute pressure. Liquid column manometer. Elastic pressure transducers: Bourdon tube, diaphragms and bellows. Membrane with strain gauges pressure transducers. Piezoelectric pressure transducers. Measurement of dynamic pressure.
Bibliography
The slides in PDF format used in the lessons.
E.O. Doebelin : Measurement Systems: Application and Design Mc Graw Hill.
https://www.ceinorme.it/it/normazione-it/vim.html
https://www.bipm.org/en/publications/guides
Teaching methods
Didactic activities are lectures regarding theoretical basis of metrology and basic principles of measurement instruments. Theoretical lessons are supported by guided practice, analysis and visualization of data with MATLAB. Slides as support for lectures will be weekly uploaded on Elly platform. To download the slides, enrolment to the course is mandatory. Slides are considered part of didactic material. It is worth remembering to non-frequenting students to check information and materials provided on Elly. The professor is available for clarifications about the lectures by appointment (via email).
Assessment methods and criteria
The exam is written and consists of a series of closed or open questions.
Questions cover the theoretical content or exercises covered in the course.
The duration of the test is 1,5 hours. The evaluation is done with the scale 0-30. The test is considered passed with a total score of at least 18 points. The honor is assigned if the maximum score is obtained in all the questions.
Answers are assessed according to the relevance and completeness of the answer and according to the mastery of the subject vocabulary.
Online registration to the exam is MANDATORY. For possible partial tests a list will be opened on Elly.
Other information
