Conducting an experiment

• Begin by reading through the entire description of the experiment. Make sure you understand the goals of the experiment before you begin. Make note of and attempt to resolve all questions that may arise during preparation, by consulting the references and/or the instructor. Do not perform experimental steps whose purpose you do not understand!
• Aim to complete each experiment in the scheduled time. Keep clear and complete records; write down answers to the questions asked as well as your own observatons without waiting to be prompted. Remember to describe the problems you encounter and how you solved them. You might run into the same difficulty a few weeks later.
• Make a preliminary measurement before you start to acquire your final results. This way, you will:
  • understand the operation of the equipment;
  • ensure that the equipment is working correctly;
  • establish the range of values, so that you can choose the optimal settings on all your instruments;
  • find out what takes the most time, and budget accordingly.
• Graph the experimental curves and staple or glue them into the lab book.

  Remember the importance of proper captions, axes' labels, specification of units, and definition of symbols. These must be done as you go along, do not wait until later as you will lose track of the settings once you change them in the course of an experiment.

• Analyze your measurements and estimate the errors.
• Keep your reports brief, with an absolute maximum length of ten pages. Reference your work, do not copy text from manuals and books. However, make sure your reports are complete. Always include properly annotated diagrams of your circuits, make sure pinouts, meter settings, and other ``trivial'' details are clearly marked. Pay attention to these details: what may seem obvious at the moment will be forgotten soon after you complete the experiment. Your lab book should contain all of the information necessary to reproduce your experiments later, and to write your lab reports away from your lab station.

  You will be required to submit seven lab reports over the course of the first ten weeks of labs (experiments #4, #5, and #6 take two weeks each). Each report is due one week after the lab date. All of these lab reports together will account for 70% of your final mark.

  Attempt to write your lab reports as if they were scientific papers. To find out what format you are expected to follow see, for example, Canadian Journal of Physics. Generally speaking, you should address the following points clearly and explicitly:

  Title

  The name of the experiment performed.

  Abstract

  A brief summary of the most important factors in the experiment including the statement of the final result and conclusions.

  Introduction

  Describe the motivation for doing the experiment, the physical principles involved, how the technique used differs from other techniques, etc.

  Procedure

  A carefully labelled diagram of the apparatus, with a description of its features; a careful account of how the measurements were done including the precautions taken to eliminate systematic errors. In simple cases, it may be sufficient to simply state that the procedure as described in the Manual was followed exactly. All changes in the procedure, modifications of the circuit or of the component values, etc. must be clearly noted.

  Results

  A tabulation of the experimental data, graph(s) where appropriate, derivation of the desired result, plus an estimate of the random and systematic errors as well as numerical fit of theoretical curves to the experimental data points where appropriate. If a computer program or a macro is used to analyze the data, its listing should be attached as an Appendix to your report.

  Discussion

  A discussion of the precision of the result, how the experiment can be improved and its ultimate limitations, possibly a comparison with other methods of obtaining the same result.

  Conclusions

  As appropriate.

  References

  All texts, publications, and other references used to assist in the experiment should be listed.

  Handwritten reports will not be accepted. You are encouraged to use TEX/L^ATEX to write your reports. A skeleton report is available for you to copy into your own filespace and to edit as appropriate. Several different programs capable of data analysis and plotting are available on the PC's in the lab and on the University Unix servers, including physica/edgr, gnuplot, maple, xmgrace, and SigmaPlot. All of these are capable of generating PostScript output which can then be included in your lab report. Consult your instructor for details.

• The last three weeks of the course are reserved for your term project, although you are encouraged to select one and start preliminary work on it as early as possible. A list of available projects should be posted in the lab early in the semester. Unlike the step-by-step experiments in this lab manual, you will be given a task, and a minimum of instructions on how to proceed.

  In lieu of a final exam, you will be required to present your project and demonstrate its operation, as well as to submit a written report on your work. Several Faculty members and representatives from the Electronics Shop usually attend these final presentations.

  Your project report may take the form of a lab report, or that of a User's Manual for your particular device. Under certain circumstances, the report may be replaced by an interactive Help facility built into the software that you have written to support your device.

  The term project (including the report) is worth 30% of the final mark.

Please refer to this outline, and to this introductory chapter throughout the course of the experiments. The marking scheme used to evaluate your work is implicitly contained here.