Andreas Richter room U2090 Tel: 218 62103 e-mail: richter@iup.physik.uni-bremen.de

1. Measurement TechniquesTechnical Information and Some Hints for the ReportsPractical Measurement Techniques, University of Bremen, SS 2011 Andreas Richter room U2090 Tel: 218 62103 e-mail: richter@iup.physik.uni-bremen.de Anna Serdyuchenko room U 4150 Tel: 218 62120 e-mail: anserd@iup.physik.uni-bremen.de

2. General information A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

3. General Information I Practical Measurement Techniquesconsistsof • a seriesoflecturesaboutselectedmeasurementtechniques in environmental science • a seriesoflecturesrelatedtothe lab experiments • the lab experiments • an oral examatthe end A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

4. Prelimiary Time Schedule: Lectures A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

5. General Information II • In total 4 lab experiments have to be completed successfully • 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 http://www.msc-ep.uni-bremen.de/services/lectures/Measurement_tech_SS11-2.html A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011 - 5 -

6. General Information III • Please get a copy of the lab instructions from the web at least 2 weeks before the lab takes place readthemcarefully – ifyoucomeunprepared, thetutor will send youhomeand fix a newdateathisconvenience • 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 each student has to hand in an individual report • For the remaining two labs one report per group is sufficient A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

7. General information IV • 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 no more than TWICE 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 atthe end ofthislectureand 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 A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

8. General information V 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. A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

9. Safety Considerations In this set of experiments, you will not be exposed to undue danger by inflammable or hazardous material or ionizing or other harmful radiation. However, you should be aware of some general safety considerations. • Don‘t eat or smoke (this might damage the experiment). • If anything is defect, inform your tutor immediately. • Never construct, modify, or disconnect electrical circuits under voltage applied. • Never look into laser beams. • Be informed about emergency exits and fire extinguisher sites. • On alert, immediately leave the lab room. • Don‘t cause danger to yourself or anybody else! A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

10. Reporting A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

11. Reporting on the experiments • for each experiment, you will have to submit a report • students ofthe same 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 (word, latex, …) • 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. Serdyuchenko). 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 A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

12. 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/her 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: • What have you done? • Why have you done it? • How have you done it? • What are the results? • What are the associated errors? • What are the conclusions? A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

13. Structure of Report • Title of the experiment: group and name of the students; date • Introduction: Short description of the experiment and its objectives • Theoretical background: Scientific background on which the experiment is based • Experimental set up: Description of the set up used; components and their principle of operation • Experimental procedure: Description of each step followed during the experiment, indicating the time and relevant details • Data analysis: Description of the data obtained, analysis and conversion procedures applied to obtain the results for interpretation • 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 • 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 • Appendix: Raw data in a table, in graphs or on CD A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

14. 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 usually not acceptable, 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, or using cut-and-paste text from some internet sourcewithoutreference, is considered to be fraud A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

15. Use of graphical data representations • Graphical representation of data and results is highly recommended , “EinBildsagtmehrals 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 A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

16. useful Fig 1: Variation of tropospheric NO2-column with latitude. Data from GEOSCHEM model for July 1997 [Martin et al., 2001] . Example for graphical representations useless A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

17. 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 A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

18. 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 A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

19. 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: In August 2011, exact times TBD Contact: Andreas Richter Anna Serdyuchenko Room: U-2090 Room: U-4150 Phone: 218-62103 Phone: 218- 62120 e-mail: richter@iup.physik.uni-bremen.de e-mail: anserd@iup.physik.uni-bremen.de A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

20. Practicals A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

21. Prelimiary Time Schedule: Practicals A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

22. The available Experiments • Satellite Image Analysis • Natural and man-made radioactivity in soil • DOAS (Differential Optical Absorption Spectroscopy) measurements of stratospheric species • Acoustic Current Measurements • FTS Measurements • Cavity Ring Down Measurements • Ozone Absorption Spectroscopy A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011

23. Ozone Absoprtion Spectroscopy • Very classical spectroscopy! • Three steps to measure your first ozone absorption: • Measure transmission spectrum of pure oxygen • - Prepare set-up (pressure, temperature and intensity stabilization) • Measure transmission spectrum of oxygen/ozone mixture - prepare ozone • Calculate the OD from Beer-Lambert law

24. Natural and Man-Made Radioactivity in Soil • Taking the soil sample • Experiments • Test source with one gamma line – effect of geometry • Test source with multiple lines – energy calibration • Efficiency calibration • Soil sample measurement • Data analysis

25. Natural and Man-Made Radioactivity in Soil

26. 210Pb 214Pb 40K 137Cs 214Bi Gamma spectrometry of soil • Hardware: coaxial HPGe detector Canberra Industries (50% rel. efficiency) housed in a 10 cm Pb shielding with Cu, Cd and plastic lining Source: Fischer 2008

27. Natural and Man-Made Radioactivity in Soil Dana Pittauerová (pittauerova@iup.physik.uni-bremen.de) Dr. Ahmed Qwasmeh (qwasmeh@iup.physik.uni-bremen.de) • room: S4250, phone 62763

28. Acoustic Current Measurements Christian Mertens (cmertens@uni-bremen.de) Determine the structure of ocean currents using data from an acoustic Doppler current profiler (ADCP) that was lowered from a research vessel to the sea floor. ADCP

29. Blue laser cavity ring-down spectroscopy of Nitrogen Dioxide (NO2) • Threestepstomeasureyourfirstabsorption: • Aligncavitieswithhigh-reflectivemirrors- align open cavityfirst- useclosedcavityforabsorptionmeasurements • Measure ring-down time constants- emptycavityfirst, get „offset“ τ0- unknownamount of NO2then, getτα • Calculate the NO2 concentration

30. Satellite Image Analysisteaching the computer to understand the image • satellite image in visible and infrared • enhance, display (e.g., as color image) • teach computer to automatically recognise surface type (e.g., water)

31. Fourier Transform Infrared Spectroscopy Fourier transformation Sunlight Intensity Beam Splitter Wavenumber [cm-1] Moving Mirror Fixed Mirror Detector A. Richter & A. Serdyuchenko, Measurement Techniques SS 2011 V o l t a i r ZPD e V .