Code: BMETE11AP65
Lecturer: András Halbritter
Mid-term tests: -
Grading: oral exam
<20 minutes/ person
First 10 minutes: discussion of the randomly drawn topic (see exam topics on next slides). The focus is on the
understanding of the concepts.
If you were absent on <= 5 lectures: you can use the slides or anything you wish both for the preparation and for this part
of the exam, and you can also request an online exam, if you wish. In case of more absences, you cannot use the slides,
and you have to make the exam in person.
Second 10 minutes: flash questions on any topic. You cannot use anything, but only the most relevant message of each
topic is asked.
Grades: 5: High level of understanding for the whole material
4: Good level of understanding for the whole material
3: Significant understanding with significant shortages
2: Weak, but still somewhat valuable knowledge
The language of the oral exam is English, but the English knowledge is not an aspect of grading.
Detailed information: Moodle page of the course
(Loosely related) literature: -Keithley Low Level Measurements handbook
-Varga Dezső és Bagoly Zsolt (ELTE TTK): Elektronika és méréstechnika
-James A. Blackburn: Modern Instrumentation for Scientists and Engineers
-Fredric J. Harris: On the use of Windows for Harmonic Analysis with the Discrete Fourier Transform Proceedings of the IEEE 66 p51–83 (1978)
-Heinzel, G.; Rüdiger, A.; Schilling, R. (2002). Spectrum and spectral density estimation by the Discrete Fourier transform (DFT), including a comprehensive list of window functions and some new flat-top windows
EXAM TOPICS:
1. A motivating experiment for the subject of measurement techniques: demonstrating the zero resistance of a superconductor. Tricks and difficulties in resistance measurement: cable and contact resistance, four-probe measurement method; digital error; nonlinear temperature sensor characteristics; hysteretic cooling and warming. More accurate experiment by an alternative method: persistent current measurement with a magnetic field sensor. The role of bridge configuration in magnetic field measurement.
2. PID regulation. The role of parameters P, I and D, the time constant of the control, problems in case of incorrect setting. Applications: temperature control, atomic distance control (scanning tunnelling microscope, STM), Michelson interferometer.
3. Ideal voltage and current sources, ideal voltage and current meters. Simple voltage and current generator circuits. Operational amplifiers: comparator, non-inverting and inverting voltage amplifier, current amplifier, logarithmic current amplifier and charge amplifier circuits.
4. D/A converter with summing amplifier circuit. Flash and successive approximation A/D converters. Data acquisition card specifications and input settings. Concepts of resolution and accuracy. Common mode rejection.
5. Basic functions of analog and digital oscilloscopes: input coupling, triggering, averaging and enhanced resolution, ultra-fast sampling methods. Measurements with oscilloscope. Synchronization, function generator burst mode. Concept of complex impedance. RC time constant problems due to stray capacitances in high frequency measurements.
6. Wave propagation in coaxial cables, telegrapher’s equations. The concept of wave impedance. Reflections at the cable end, the role of impedance matching. Measurement of signal propagation speed by standing wave and time of flight methods. Reflection and transmission on in-line resistors.
7. Suppression of external interference: electrostatic coupling, shielding and grounding; inductive coupling, twisted pairs; low-frequency disturbances caused by high-frequency interference rectification; thermoelectric voltages, offset compensation; concept of guarding.
8. Fourier series, Fourier transform. Fourier integral over a finite time interval. Discrete Fourier Transform (DFT), consequences of the Nyquist-Shannon sampling theorem.
9. Concept and properties of window functions. Spectral leakage, frequency resolution, amplitude accuracy, and the role of normalization. Properties of rectangular, Hanning and flattop windows. Why can we suppress spectral leakage by a window decaying at the sides of the measurement interval?
10. Concept of fast Fourier transform, FFT spectrum analyzers. Further methods of spectrum analysis: heterodyne techniques, hybrid and swept tuning spectrum analyzers.
11. The principle of the lock in amplifier. Phase locked loop, PLL synchronization to external reference signal. Measuring a small signal in a noisy environment using a modulation technique. Noise filtering considerations – why should we use a lock-in? Higher harmonic measurements with a lock-in.
12. Experimental definition of noise. The spectral density of noise, the Fourier transform of the current-current correlation function and the Fourier transform of the current fluctuations, and the relationship between these quantities. Spectral density calculation based on DFT.
13. Thermal noise calculation, relation between conductance and noise through the correlation time. Minimum input noise of a current amplifier. Cross correlation measurement technique.
14. Shot noise of independently emitted electrons, electron charge measurement. Equivalent noise bandwidth. Resistance fluctuations, 1/f type noise. Aliasing in noise measurement, antialiasing filter.
15. International System of Units (SI). Old and new definitions of basic units, reasons for the introduction of the new SI system. Historical evolution of time and distance measurement.
16. Atomic clock as a time standard. The quantum metrology triangle: converting voltage to time through the Josephson effect, current to voltage through the quantized Hall effect and current to time by electron pumps. Mass measurement: Watt balance and Avogadro project.
17. Magnetic field sensors: inductive sensors; magnetoresistive sensors (anisotropic magnetoresistance, giant magnetoresistance and spin valve sensors, tunneling magnetoresistance), Hall probes, SQUIDs.
18. Distance and position sensors: inductive sensors, capacitive sensors, touch screen with pressure sensitive pen, laser rangefinders and ultrasonic distance sensors, LIDAR system.
19. Temperature sensors, primary and secondary thermometers. Thermocouples, resistance thermometers, thermistors. Light and electromagnetic radiation sensors: photodiodes, CCD sensors, CMOS active pixel sensors, bolometers. Accelerometers: MEMS accelerometers and gyroscopes, piezoelectric accelerometers.
20. Measurement of radiation and particles. Interactions of ionizing radiation and matter, neutral particle detection. Gas-filled ionization detectors: ion chambers, proportional counters and Geiger-Müller tubes. Scintillation detectors with photoelectron multipliers. Applications. Fundamentals of nuclear electronics, integral and pulse mode detection, energy resolved spectra.
Lecturer: András Halbritter
Mid-term tests: -
Grading: oral exam
<20 minutes/ person
First 10 minutes: discussion of the randomly drawn topic (see exam topics on next slides). The focus is on the
understanding of the concepts.
If you were absent on <= 5 lectures: you can use the slides or anything you wish both for the preparation and for this part
of the exam, and you can also request an online exam, if you wish. In case of more absences, you cannot use the slides,
and you have to make the exam in person.
Second 10 minutes: flash questions on any topic. You cannot use anything, but only the most relevant message of each
topic is asked.
Grades: 5: High level of understanding for the whole material
4: Good level of understanding for the whole material
3: Significant understanding with significant shortages
2: Weak, but still somewhat valuable knowledge
The language of the oral exam is English, but the English knowledge is not an aspect of grading.
Detailed information: Moodle page of the course
(Loosely related) literature: -Keithley Low Level Measurements handbook
-Varga Dezső és Bagoly Zsolt (ELTE TTK): Elektronika és méréstechnika
-James A. Blackburn: Modern Instrumentation for Scientists and Engineers
-Fredric J. Harris: On the use of Windows for Harmonic Analysis with the Discrete Fourier Transform Proceedings of the IEEE 66 p51–83 (1978)
-Heinzel, G.; Rüdiger, A.; Schilling, R. (2002). Spectrum and spectral density estimation by the Discrete Fourier transform (DFT), including a comprehensive list of window functions and some new flat-top windows
EXAM TOPICS:
1. A motivating experiment for the subject of measurement techniques: demonstrating the zero resistance of a superconductor. Tricks and difficulties in resistance measurement: cable and contact resistance, four-probe measurement method; digital error; nonlinear temperature sensor characteristics; hysteretic cooling and warming. More accurate experiment by an alternative method: persistent current measurement with a magnetic field sensor. The role of bridge configuration in magnetic field measurement.
2. PID regulation. The role of parameters P, I and D, the time constant of the control, problems in case of incorrect setting. Applications: temperature control, atomic distance control (scanning tunnelling microscope, STM), Michelson interferometer.
3. Ideal voltage and current sources, ideal voltage and current meters. Simple voltage and current generator circuits. Operational amplifiers: comparator, non-inverting and inverting voltage amplifier, current amplifier, logarithmic current amplifier and charge amplifier circuits.
4. D/A converter with summing amplifier circuit. Flash and successive approximation A/D converters. Data acquisition card specifications and input settings. Concepts of resolution and accuracy. Common mode rejection.
5. Basic functions of analog and digital oscilloscopes: input coupling, triggering, averaging and enhanced resolution, ultra-fast sampling methods. Measurements with oscilloscope. Synchronization, function generator burst mode. Concept of complex impedance. RC time constant problems due to stray capacitances in high frequency measurements.
6. Wave propagation in coaxial cables, telegrapher’s equations. The concept of wave impedance. Reflections at the cable end, the role of impedance matching. Measurement of signal propagation speed by standing wave and time of flight methods. Reflection and transmission on in-line resistors.
7. Suppression of external interference: electrostatic coupling, shielding and grounding; inductive coupling, twisted pairs; low-frequency disturbances caused by high-frequency interference rectification; thermoelectric voltages, offset compensation; concept of guarding.
8. Fourier series, Fourier transform. Fourier integral over a finite time interval. Discrete Fourier Transform (DFT), consequences of the Nyquist-Shannon sampling theorem.
9. Concept and properties of window functions. Spectral leakage, frequency resolution, amplitude accuracy, and the role of normalization. Properties of rectangular, Hanning and flattop windows. Why can we suppress spectral leakage by a window decaying at the sides of the measurement interval?
10. Concept of fast Fourier transform, FFT spectrum analyzers. Further methods of spectrum analysis: heterodyne techniques, hybrid and swept tuning spectrum analyzers.
11. The principle of the lock in amplifier. Phase locked loop, PLL synchronization to external reference signal. Measuring a small signal in a noisy environment using a modulation technique. Noise filtering considerations – why should we use a lock-in? Higher harmonic measurements with a lock-in.
12. Experimental definition of noise. The spectral density of noise, the Fourier transform of the current-current correlation function and the Fourier transform of the current fluctuations, and the relationship between these quantities. Spectral density calculation based on DFT.
13. Thermal noise calculation, relation between conductance and noise through the correlation time. Minimum input noise of a current amplifier. Cross correlation measurement technique.
14. Shot noise of independently emitted electrons, electron charge measurement. Equivalent noise bandwidth. Resistance fluctuations, 1/f type noise. Aliasing in noise measurement, antialiasing filter.
15. International System of Units (SI). Old and new definitions of basic units, reasons for the introduction of the new SI system. Historical evolution of time and distance measurement.
16. Atomic clock as a time standard. The quantum metrology triangle: converting voltage to time through the Josephson effect, current to voltage through the quantized Hall effect and current to time by electron pumps. Mass measurement: Watt balance and Avogadro project.
17. Magnetic field sensors: inductive sensors; magnetoresistive sensors (anisotropic magnetoresistance, giant magnetoresistance and spin valve sensors, tunneling magnetoresistance), Hall probes, SQUIDs.
18. Distance and position sensors: inductive sensors, capacitive sensors, touch screen with pressure sensitive pen, laser rangefinders and ultrasonic distance sensors, LIDAR system.
19. Temperature sensors, primary and secondary thermometers. Thermocouples, resistance thermometers, thermistors. Light and electromagnetic radiation sensors: photodiodes, CCD sensors, CMOS active pixel sensors, bolometers. Accelerometers: MEMS accelerometers and gyroscopes, piezoelectric accelerometers.
20. Measurement of radiation and particles. Interactions of ionizing radiation and matter, neutral particle detection. Gas-filled ionization detectors: ion chambers, proportional counters and Geiger-Müller tubes. Scintillation detectors with photoelectron multipliers. Applications. Fundamentals of nuclear electronics, integral and pulse mode detection, energy resolved spectra.
- Teacher: Szabolcs Csonka
- Teacher: András Ernő Halbritter