93814 - SENSORI E TECNICHE DI MISURA AVANZATE PER L'INGEGNERIA M

Academic Year 2021/2022

  • Teaching Mode: Traditional lectures
  • Campus: Bologna
  • Corso: Second cycle degree programme (LM) in Mechanical Engineering (cod. 5724)

Learning outcomes

The course aims at providing notions related to the selection, use and performance of different types of sensors, either traditional or advanced, for the measurement of mechanical and thermal quantities. Signal conditioning and acquisition techniques will also be treated, as well as modern virtual instrumentation for signal processing. The course includes hands-on lessons on the use and application of some of the sensors presented during the course and their interfacing to data acquisition systems.

Course contents

Measurement performance of sensors

Measurement systems configurations: active and passive sensors, analog and digital sensors, principal and interfering inputs. Static characteritics of sensors: static calibration, measurement uncertainty and reference regulations. Dynamic characteristics of a sensor: transfer functions, order I and II sensors, basics of signal analysis.

Dimension, displacement and velocity measurements

Callipers, potentiometres, LVDTs, piezoelectric, capacitance and optical proximity sensors. Incremental and absolute encoders. Lase Doppler interferometers and velocimeters.

Absolute displacement, velocity and acceleration measurements

Sismometers. Accelerometers and piezoelectric accelerometers. Accelerometer calibration.

Deformation measurements

Strain gages. Resistance strain gages: types, applications, manufacturing and fixing of sheet strain gages, Wheatstone bridge, temperature effect, strain measurement configurations. Digital Image Correlation. Modern optical strain gages: fiber Bragg gratings, distributed measurement techniques.

Force, torque and power measurements

Scales and piezolelectric and strain gage load cells. Torquemeters. Mechanical, hydraulic and magnetic dynamometers.

Pressure measurements

Manometers, piezoelectric, piezoresistive and capacitive pressure sensors. Sound pressure and intensity gages.

Flow velocity and rate measurements

Pitot tube, hot wire anemometry, Laser Doppler Anemometer (LDA), Particle Image Velocimetry (PIV).

Readings/Bibliography

Handouts for the course are available on the virtual learning platform (https://virtuale.unibo.it), as well as the copies of the presentations used in the classroom. The teaching material is sufficient to prepare the examination. The presentations copies alone are useful to take notes or as schemes to support the study, which must however be deepened on the handouts. The books reported in the following list are useful for further deepenening of the course contents.

Reference books:

E.O. Doebelin, Strumenti e Metodi di misura , McGraw Hill

Other books

R. Figliola, D. Beasley, Theory and design for Mechanical Measurements, Ed. Wiley&Sons

G. Minelli, "Misure meccaniche", Patron

Teaching methods

Teaching is divided into lectures in the classroom, that will be held both in presence and online.

Assessment methods

The assessment of the learning outcomes is done through a written examination. The latter aims at verifying the knowledge acquired during the course, related to the execution and related issues of measurements under both static and dynamic conditions, and the operation and calibration of instruments analysed during the course.

The written test consists of three open questions, composed of some sub-questions, of which at least one is focused on the first part of the course, i.e. static and dynamic performance of measurement systems.

In the event of full pass, the obtained grade can be confirmed or an oral examination taken.

Teaching tools

Videoprojector, pc.

Office hours

See the website of Raffaella Di Sante

SDGs

Quality education Industry, innovation and infrastructure

This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.