1. 1 Measurement Techniques Technical Information and Some Hints for the Reports Practical Measurement Techniques, University of Bremen, SS 2008 Andreas Richter room U2090 tel: 218 4474 e-mail: richter@iup.physik.uni-bremen.de Astrid Bracher room U 3215 tel 218 8958 e-mail Astrid.Bracher@awi.de

2. A. Richter & A. Bracher, Measurement Techniques SS 2008- 2 - General Information I In total 4 lab experiments have to be completed successfully One lab (Satellite Image Analysis) takes place during the present term break. The remaining 3 labs will take place during the summer term The labs will take place on Wednesdays from 10 a.m. until 5 p.m. if not stated otherwise The labs will be performed in groups of 2 students each Lab instructions, including descriptions of the experimental setup, the tasks to be performed and further literature are available for every experiment on the Measurement Techniques website The “Measurement Techniques“ folder in the PEP office also contains all the lab instructions and in some cases additional material

3. A. Richter & A. Bracher, Measurement Techniques SS 2008- 3 - General Information II Please get a copy of the lab instructions at least 2 weeks before the lab takes place At least one week before the labs take place contact the lab instructor about the exact time and location of the lab, and perhaps have a first look at the instruments you will use For each lab experiment a lab report / protocol has to be written For the first two of the four labs (Satellite Image Analysis and the second one) each student has to hand in an individual report For the remaining two labs one report per group is sufficient

4. A. Richter & A. Bracher, Measurement Techniques SS 2008- 4 - General information III The complete reports have to be handed in 2 weeks after the lab to the tutor If the report is not accepted by the lab instructor it can be corrected ONCE within two weeks after receiving it from the lab instructor A special report form will accompany you through the practical and the review process. This form will be given to you during the first lab and has to be handed in at the end of semester You will need this report with all signatures to be admitted to the oral exam

5. A. Richter & A. Bracher, Measurement Techniques SS 2008- 5 - General information IV Note: If you:  fail to show up,  are not prepared appropriately,  submit a revised report which is still not accepted by the instructor you will have to do an additional experiment at the end of the semester to be admitted for the exam. Extra experiments can only be done once and should you fail this one also, you will not pass the course.

6. A. Richter & A. Bracher, Measurement Techniques SS 2008- 6 - The available Experiments Satellite Image Analysis (done during term break) Natural and man-made radioactivity in soil Ozone and NOx measurements DOAS (Differential Optical Absorption Spectroscopy) measurements of stratospheric species Acoustic Current Measurements FTS Measurements

7. A. Richter & A. Bracher, Measurement Techniques SS 2008- 7 - Time Schedule Date ABCDEF March 6Lectures March 25 – April 3 Satellite Image Analysis April 9Lectures April 16Lectures April 23Lectures April 30Lectures May 7Radioactivity Ocean FTS May 14DOASOcean FTS May 21FTSDOAS Ocean May 28 FTS O3Ocean June 4DOASRadioactivityO3 June 11OceanRadioactivityDOAS July 9 Lecture July 16 Oral Exams July 17 Oral Exams

8. A. Richter & A. Bracher, Measurement Techniques SS 2008- 8 - Reporting on the experiments for each experiment, you will have to submit a report students within one group submit two separate and two joint reports after the experiment, you have 2 weeks for writing the report and submitting it to the tutor reports are prepared with a word processor the length of the report is typically 6 – 8 pages the supervisor will read the report and usually ask for some revisions / corrections / additions / changes you then have another week to submit a corrected report if necessary, you will have to submit a second revision should the supervisor still not accept your report, this will be discussed with the lecturers (A. Richter and A. Bracher). If all else fails, you will have to take another (additional) experiment only when all your reports have been accepted, you will be admitted to the oral exam

9. A. Richter & A. Bracher, Measurement Techniques SS 2008- 9 - Contents of the Report ideally, your report should enable another scientist to set-up a similar experiment, to repeat the measurements and to compare his results with yours it should also give the motivation why things have been done the way they were done for the purpose of the practical, it should show that you have understood the experiment questions to answer in the report: 1.What have you done? 2.Why have you done it? 3.How have you done it? 4.What are the results? 5.What are the associated errors? 6.What are the conclusions?

10. A. Richter & A. Bracher, Measurement Techniques SS 2008- 10 - Structure of Report 1.Title of the experiment; group and name of the students; date 2.Introduction: Short description of the experiment and its objectives 3.Theoretical background: Scientific background on which the experiment is based 4.Experimental set up: Description of the set up used; components and their principle of operation 5.Experimental procedure: Description of each step followed during the experiment, indicating the time and relevant details 6.Data analysis: Description of the data obtained, analysis and conversion procedures applied to obtain the results for interpretation 7.Results and error analysis: Final numerical and graphical results with the corresponding associated error. A detailed description of the error analysis should also be included 8.Discussion of results: Interpretation of the final results in relation to the objectives of the experiment. You can use the questions given in the instructions for the experiment as a guideline 9.Appendix: Raw data in a table, in graphs or on a floppy disk / CD

11. A. Richter & A. Bracher, Measurement Techniques SS 2008- 11 - Use of external sources of information in addition to the explanations provided in the experiment description and lecture, you are expected to use other sources of information (papers, books, web pages, discussion with your colleagues) any information source used must be acknowledged in the text through appropriate citations quoting another text verbatim (“cut and paste”) is rarely a good idea and has always to be indicated by using quotation marks if you can’t say it in your own words, you have probably not understood it quotes from the experiment description are not acceptable using data or text from the reports of other groups is considered to be fraud

12. A. Richter & A. Bracher, Measurement Techniques SS 2008- 12 - Use of graphical data representations Graphical representation of data and results is highly recommended “Ein Bild sagt mehr als 100 Worte” All figures must have  clear axis labels indicating the quantity plotted and the units used  figure captions explaining the contents of the figure  figure numbers for reference  proper reference and explanation in the text figures must be large enough to see all the necessary details line thickness and symbol sizes must be adequate, colours often help the ranges used for x and y axis must be appropriate for the range of values shown individual measurement points should be shown by symbols connecting lines should usually be linear, not spline or polynomials where possible, add error bars

13. A. Richter & A. Bracher, Measurement Techniques SS 2008- 13 - Example for graphical representations useless Fig 1: Variation of tropospheric NO 2 -column with latitude. Data from GEOSCHEM model for July 1997 [Martin et al., 2001]. useful

14. A. Richter & A. Bracher, Measurement Techniques SS 2008- 14 - Numerical results often, a numerical result is expected from your experiment all numerical results have to be given with units checking units often helps to find errors all results must be accompanied by error estimates the number of digits given must make sense with the errors:  E = 13.45278456 +-2.54378 W m -2 => E = 13.5 +-2.5 W m -2  E = 3E8 +-2.5 W m -2 => E = 31 786 209 +- 2.5 W m -2 all results should be put into context e.g.  is of expected order of magnitude  lies within 5% of the predicted value  is twice as large as expected for clean situations

15. A. Richter & A. Bracher, Measurement Techniques SS 2008- 15 - Overall form form matters! use section numbering use clear section headers use numbering for equations, figures and tables don’t forget page numbers before submitting, check your report for  logic  completeness  grammar and spelling submit your report in a binder and not as a staple of sheets clearly indicate your names, date of the experiment, date of submission of report on the cover sheet

16. A. Richter & A. Bracher, Measurement Techniques SS 2008- 16 - Final Exam Type of exam:Oral exam (45 minutes) Prerequisites: Successful completion of all 4 labs Content:15 minutes presentation on one experiment Questions related to the lectures Questions to the 4 labs Date:On July 16 and 17, 2008 exact times TBD Contact: Andreas RichterAstrid Bracher Room: U-2090Room: U-3215 Phone: 218-4474Phone: 218- 8958 e-mail: richter@iup.physik.uni-bremen.de e-mail: Astrid.Bracher@awi.de