MECH 322 Instrumentation

Goals

Course Evaluation

My Goals• Observe and Measure Important Physical

Phenomena – Hydrostatic pressure head, manometer fluid shift– Beam bending, strain, elastic modulus (steel and aluminum)– Bernoulli fluid pressure variation with speed (Venturi tube and

Pitot probe)– Boiling water temperature variation with pressure– Seebeck effect (voltage produced at junction of dissimilar

metals)– Heat transfer coefficient dependence on fluid conductivity– Beam vibration frequency and damping– Karman vortex frequency– Feedback control (full on/off, proportional, integral)– Errors in processing time varying signal caused by noise and

aliasing – Predicted, Unpredicted, and Unpredictable behaviors

• In lab we sometimes observe things we did not expect• Requires reinterpretation and/or troubleshooting

Help students feel comfortable using instrumentsand data acquisition and control systems

• Understand theory of operation• Monometers, pressure transmitters• Strain gages, bridge• Pitot probes, venturi, hot film anemometers• MyDAQ and LabVIEW• Thermocouples, signal conditions, LM35• Accelerometers• Digital Relays • DMM, micrometers, rulers, scales…

My Goals• Perform steady and transient measurements,

understand potential errors – Bias (calibration) – Random (not repeatable)– Transient (instrument requires times to respond)

• Communicate– Use clear tables and charts to present engineering

data– Analyze and draw conclusions based on data

• Engineering understanding begins after the measurements (or calculations) are completed

• Students will not be afraid of doing experiments– Will find them “rewarding

• Reasonable work load– Requires focus– ”

Focus Each Lab had Stages

• Clear handouts and lectures (I tried!)– New this year: Lecture Slides

• Web Site – easy materials access• Lab Preparation Homework and Sample Reports

– Help students know what is expected – Reduce lab time confusion– Tutorials– Do these make the make the lab too easy?

• LabVIEW programming by example, not theory • Write reports in lab:

– Analyze soon after data acquisition (allows re-acquisition)– Gives student access to instructor help

• Bulleted conclusion format – Outlines formal reports (prepare for senior year)

Next Year• Lab 10 (beam vibration), redo with a second

weight, analyze exponential damping

• Lab 12: Add Integral Control

• Offer “Lab-in-a-Box” for check out– Materials for Boiling Water Temperature,

Transient TC, and Control labs – Gives students an opportunity to learn how to do

labs at home• Removes lab time constraint• Gives students opportunity to explore• Potential breakage and liability problems

Feedback

• Did you like – Lab preparation problems– Finishing labs in three hours

• Did the Lab Assistants solve too many problems for you?• Was the lab too structured

– Would you have liked more time to explore things?

• What you like to see more low-priced chip-based transducers that you can buy online and use on your own?

• Were the lab calculation lectures– Too detailed (waste of time) – Just right (Clear and helpful)– Too vague (can’t understand)

Feedback

• Now

• E-mail (greiner@unr.edu)

• Please do the evaluation now–https://wcl.unr.edu/

–Two Parts–Instructor–Learning Outcomes

PART I A: EVALUATION OF THE INSTRUCTOR

1. The instructor was effective in facilitating learning in the classroom2. The instructor was well prepared and organized 3. The instructor encouraged student questions and participation in class4. The instructor was available and helpful outside of class5. The instructor demonstrated a thorough knowledge of the course content6. The instructor provided a clear course syllabus and completed the course objectives7. Exams and assignments were appropriate and covered the course content and objectives.8. The pace and amount of work required for this course were appropriate

PART I B: COURSE INFORMATION AND EVALUATION1. The textbook and handouts contributed to your learning2. The audiovisual materials used in the classroom contributed to your learning3. The computer resources were adequate and were effectively incorporated into teaching4. The classroom environment was conducive to learning

PART II: STUDENT DEVELOPMENT EVALUATION (1, 2, 5, 7, 9, 11)

This course increased my:

1. ability to apply mathematics, science, and engineering

2. ability to design and conduct experiments, and analyze and interpret data

3. ability to design a system, component, or process to meet a desired need

4. ability to function on multidisciplinary teams

5. ability to identify, formulate, and solve engineering problems

6. understanding of professional and ethical responsibilities

7. ability to communicate effectively

8. understanding of the impact of engineering solutions on society and the world

9. recognition of the need for and the ability to engage in life-long learning

10. knowledge of contemporary issues

11. ability to use modern engineering tools and skills necessary for engineering practice

5 Statistical Methods Labs

1. UNR Quad Measurement– Find grass seed cost and uncertainty, very practical

2. Quad Data Analysis– Mean, St. Dev (Data Exclusion, Correlation Coefficient)– Wide range of results highlights need for calibration

3. Monometer Calibration– Calibration removes bias – Standard Deviation of output and input quantifies impression

4. Strain Gage Installation– length error estimates

5. Elastic Modulus Measurement– Uncertainty in best fit slope – Propagation of error, compare calculated to literature value

• Written Midterm

3 Steady and Data Acquisition Labs

6. Air Speed and Volume Flow Rate – Use pressure transmitters, check consistency– Propagation of error

7. Steady Temperature of Boiling Water at Elevation– TC, signal conditioner, LabVIEW, compare with

prediction

8. Numerical Differentiation and Spectral Analysis of Unsteady Signals

– Sampling Rate Theory, Time derivatives– Demonstrate unsteady data processing errors and

solutions

• Written Midterm

4 Unsteady Measurement Labs

9. Transient Response of a Thermocouple– Heat transfer in water and air (effect of kFluid)– uncertainty

10.Vibration of a Weighted Cantilever Beam– Natural frequency prediction and damping– uncertainty

11.Karmon Vortex Unsteady Speed– Dynamic measurement and spectral analysis– uncertainty

12.Temperature Feedback Control– Analog output, digital relay, logic

• Lab Practicum Final

EvaluationME Curriculum has 14 outcomes

1. The course increased my ability to apply the principles of mathematics, science, and engineering

Instrument models, dynamic response of TC, vibrating beam, error analysis

2. The course increased my ability to conduct and design experiments, as well as to analyze and interpret data

Focused on understanding and performing experiments 3. (not applicable) The course increased my ability to identify and

document desired needs and to design a system component, or process to meet desired needs within realistic constraints such as economic, environmental, social, political, ethical, health and safety, manufacturability, and sustainability

4. (not applicable) The course increased my ability to function on multi-disciplinary teams

5. The course increased my ability to identify, formulate, and solve engineering problems

Lab experiences require interpreting measurements, dealing with unexpected results, and troubleshoot problems

6. (not applicable) The course increased my ability to explain professional and ethical responsibility and identify professional and ethical issues

7. The course increased my ability to communicate effectively

Quantitative engineering communication using tables and charts Draw bulleted conclusions from dataAbstract of resultsFormal citations

Evaluation (cont)8. (not applicable) The course enhanced my broad education

necessary to understand the impact of engineering solutions in a global, economic, environmental, and social context

9. (not applicable) The course increased my ability to explain the need for, and an ability to, engage in life-long learning

10. (not applicable) The course increased my ability to identify and analyze contemporary issues

11. The course increased my ability to use the techniques, skills, and modern engineering tools necessary for engineering practice

Modern measurement instrumentation Computer Data Acquisition and Control program

12. The course increased my ability to apply the principles of science, including chemistry and calculus-based physics, in the identification, formulation, and solution of engineering problems; with depth in at least one of chemistry or calculus-based physics knowledge domains.

Newton’s law analysis: Vibrating beamFirst law analysis: Dynamic response of thermocouple

13. (not applicable) The course increased my ability to apply the principles of mathematics and computational methods, including multivariable calculus and differential equations, in the identification, formulation, and solution of engineering problems.

14. The course increased my familiarity with statistics and linear algebra.

Sample mean, standard deviationLinear Regression, St Dev of fit, Propagation of Error

Open Ended Lab/Design• Revisit One Unsteady Lab

– student choice, improve or “fix problems”

• Damped Vibration of a Cantilever Beam– Rigid fixture, steel beam, different weights

• Karmon Vortex Unsteady Speed– Vary cylinder diameter and distance to probe

Student Posed Labs

• Student poses a question

• Design and perform an experiment to answer it

• (+) More motivated self learning

• (-) Slower, more student and instructor effort for the same basic skills than “directed study”