Activating a Second Year Measurement Lab Sequence

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Activating a Second Year Measurement Lab Sequence

• Rick Sellens
• Mechanical and Materials Engineering
• Queens University at Kingston, Canada

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Youre here, so you read the paper, right?

• I can start from there and talk about the MECH
  215 Labs

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Youre here, so you read the paper, right?

• I can start from there and talk about the MECH
  215 Labs
• Do your students all show up to labs having read
  the advance material?
• My students
• Dont read it in advance
• Read only the procedure during the lab session,
  and only if they have to
• Read only the reporting requirements after the
  lab session
• Your students may be different

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Key Points (from your reading)

• Active learning is good
• Messy problems with imperfect information are
  good
• Simple equipment is not bad
• Students can do a lot in a lab if you make them
  do it
• Having a faculty member (or similar) in the lab
  is good (and not as expensive as you might think)

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Traditional Labs

• Maybe not 75 yrs old
• Do follow a recipe
• Should be foolproof
• Deliver consistent, predictable results
• Illustrate an important theoretical effect
• Maximize throughput
• Keep students from messing with the equipment

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TAs and Students as Co-Conspirators

• A well constructed, well documented lab can run
  without faculty monitoring
• Both TAs and Students want to finish quickly and
  easily
• Both want good results
• Good report
• Easy to write
• Easy to mark
• 9 out of 10

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Why Active Learning?

• Read, Hear, See, Touch, DO!
• All the usual good pedagogical advantages, plus
• They will do the lab activity, even those who
  would never read the section in the text book or
  lab hand out.

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Thermometers Too Easy?
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Incomplete Information

• Do ask for transient behaviour of the
  thermometer.
• Dont specify
• How to time it
• How often to measure
• How long to measure
• Force students to make a decision
• Then check the data to see if the decision was a
  good one

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Just-in-Time Knowledge Delivery

• Wait for the questions to form from the
  observation
• Why the decay to equilibrium?
• Why did it heat faster than it cooled?
• Now they want to know something about heat
  capacity and convection coefficients
• Now is a good time to deliver

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Planned Failure

• We learn most about systems while troubleshooting
  them.
• Why is your measurement not working?

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Multiple Paths to Success

• Decide on a thermocouple reference source
  bricks provided, or snow, or room temperature.
• Decide how to read the voltage
• DVM more accurate on voltage
• A/D more frequent sampling on accurate timebase

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Lab 0 Labview Programming

• We found they needed a cookbook for this one
• Build their own virtual instrument to use
  throughout the remaining labs
• Need to have a canned VI as a fallback for
  trouble in this lab and later

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Lab 1 General Instrumentation

• Play with basic instruments to find out what they
  can and cant do.
• Get used to measuring transients dynamic
  systems are key
• Run around the room measuring everybody elses
  set up quality

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Lab 2 Temperature Measurement

• Students weld up their own thermocouples
• Lots of troubleshooting bad connections
• Whose weld is best? (small bead, fast response)

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Lab 3 Stress and Strain

• Students apply and solder strain gauges
• High success rate!

• Calibrate with weights of your choice

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Lab 4 Position Measurement

• Decide how to measure position with a rotary
  potentiometer
• Which team member can produce most nearly
  constant angular velocity?
• Differentiate noisy data, twice
• Play with GPS or optical tracking to measure
  capabilities

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Lab 5 Pressure and Flow

• Transients in vacuum cleaner
• Transients in Manometer
• Fast solid state transducers
• Actual results a combination
• How high can you blow?
• Balloon popping step function?

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Costs of being more active

• Traditional lab 2 TAs can do three groups in 2
  3 hours
• MECH 215 A faculty member and 2 Tas can do ten
  groups in 2 3 hours
• Maybe we can afford to have faculty there for the
  whole lab experience(Can we get them to do it?)

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Conclusions

• Active learning is good
• Messy problems with imperfect information are
  good
• Simple equipment is not bad
• Students can do a lot in a lab if you make them
  do it
• Having a faculty member (or similar) in the lab
  is good (and not as expensive as you might think)