An exploration of measurement of the most important physical quantities, by the application of sensors based on a variety of physical principles, in conjunction with electronic systems appropriate and adequate to the measurements in question.
· Main components of generic sensor/instrumentation system
- Sensor/ transducer (characterization of sensor performance in terms of their linearity, working range, sensitivity, hysteresis, repeatability and reproducibility)
- Signal conditioning element
- Signal processing element
- Control/feedback loop
- Data presentation
· Review of physical effects used for sensing: resistive, capacitive, inductive, thermoelectric, piezoelectric, pyroelectric, photovoltaic, etc.
· Sensors and associated electrical circuits for measuring:
- Temperature (thermistors, RTDs, thermocouples/thermopiles, Si based temperature sensors);
- Strain;
- Displacement/Force (using resistive (for both linear and angular displacement), capacitive, inductive and ultrasound sensors).
· Measurement techniques for electrical sensors with small and large dR:
- Voltage dividers (with examples of Thevenin and Norton equivalent circuits calculations);
- Bridges for strain gauge measurements (Wheatstone and Kevin double bridge);
- Tuned amplifiers;
- Lock-in amplifiers.
· Noise and interference in electronic measurement systems:
- Sources of noises and interference in electronic measurement systems and methods to eliminate them (for example autocorrelation and so forth).
- Bandwidth, noise figure, SNR, noise temperature.
· Dynamic behaviour of sensors measurement systems:
- Examples and behaviour of zero-order, first-order, and second-order systems;
- Natural and forced (step and sinusoidal) responses;
- Damping and Q-factor;
- Frequency response;
- Laplace transforms.
· Four terminal networks and loading:
- The effects of electrical loading;
- Resistive ladder networks;
- Characterisation of four terminal networks using Z-parameters, Y-parameters, A-parameters, Hybrid parameters, S-parameters and their combinations;
- T and pi networks for attenuation and filtering.
- Transmission lines and related impedance, inductance and capacitance.
· Biasing requirements and frequency response of practical operational amplifiers (and BJT and FET based amplifiers) for use with sensors measurement systems.
· Data conversion using DACs and ADCs:
- weighted summation, binary resistive ladder.
- voltage to time, dual-slope, ADCs based on DACs, ramp, successive approximation, tracking, sigma-delta. Flash ADCs.
· Sampling problems in digitization: quantization error, ADC non-linearities, jitter, aliasing, spectral folding, Nyquist, anti-aliasing filters, sample-and-hold circuits.
· The Intelligent multivariable measurement systems
- Modern Touch pad technologies
- E-nose technologies
- Pattern recognition
· Radiometry & photometry: Definitions, units. Wavelength dependence of detectors and windows. Thermal detectors of radiation; photon detectors, bolometers and basic associated electronic circuitry considerations, fibre optics.
Reliability, Choice and Economics of Measurement Systems
•Lectures
•Laboratory classes
•Problem-solving assignments
•Tutorials
•Web-based self-learning materials e.g. vendors’ sites and recent conference and journal papers.
| Module Content & Assessment | |
|---|---|
| Assessment Breakdown | % |
| Formal Examination | 80 |
| Other Assessment(s) | 20 |