Massachusetts Institute of Technology Department of Electrical Engineering and Computer Science 6.002 -Electronic Circuits Spring 2007 Lab Practice & Safety Handout S07-006 Introduction This handout discusses aspccts of thc cxpcri~nc~ital Itlab work that you will pcrforni in 6.002. bcgins witli a discussion of good lab practice, and ends witli a discussion of lab safcty. You should pay spccial attcntion to tlic EECS Elcctrical Safcty Noticc attachcd to thc cnd of this handout (H07). As indicated, it niust bc signcd and rcturncd to tlic EECS I~istru~ncnt Dcsk in tlic Lab in ordcr for you to pick up your lab kit. Your Lab Notebook Your lab notcbook should bcco~nc a coniplctc and pcrlnanc~it rccord of tlic cxpcrimcnts you pcrfor~n during thc scnicstcr. Tlic notcbook itsclf should bc a bound hard covcr ~iotcbook with graph-rulcd pagcs. Sincc your lab notcbook should co~itaili your raw cxpcrimc~ital data, you should ncvcr copy data into your lab notcbook from somc othcr papcr. If you do not liavc your lab notcbook with you whcn you rccord your data, you should staplc thc pagc of raw data into your lab notcbook. Copying data into your lab ~iotcbook aftcr coniplcting an cxpcrinicnt risks beautifying your lab notcbook witli copying crrors. Likc any lab notcbook, your 6.002 lab ~iotcbook should contaili tlircc distinct scctions for cacli cxpcri~ncnt pcrfornicd: (1) thc dcsign, analysis and prcdictio~is you co~nplctc bcforc your cxpcrimcntal work: (2) thc data and obscrvations you rccord during your cxpcriniclltal work; (3) and tlic analysis and intcrprctations you colnplctc aftcr your cxpcrimc~ital work If your lab notcbook is organized in this nianncr, thcn anyone, includi~ig yoursclf, should bc ablc to pick up your lab notcbook at a latcr time and follow your prcli~ninary analysis, reconstruct tlic cxpcri~ncntsyou pcrformcd, rcproducc your raw data, and rcacli cquiwlcnt conclusions. Sincc your lab work is only uscful if it can bc cxplai~icd to and rcproduccd by othcrs, your lab notcbook niust bc niorc than analyscs and ~iunibcrs witli no contcxt. Thc following guidclincs should hclp you producc niorc consistc~it lab rccords witli clcas distinctions bctwccn your cxpcctations: your actual data, and your a~ialysis of thc data. PT~-Lab Wr,r.k Prc-lab work is dcsigncd to ~notivatc and dcfinc your cxpcrinicnts~ and thus prcparc you for your in-lab work. Prc-lab work sliould bc trcatcd likc a sniall liomcwork, and sliould bc writtcli up in Cite as: Anant Agarwal and Jeffrey Lang, course materials for 6.002 Circuits and Electronics, Spring 2007. MIT OpenCourseWare (http://ocw.mit.edu/), Massachusetts Institute of Technology. Downloaded on [DD Month YYYY].your lab notcbook. Thc qucstions askcd in thc 6.002 prc-lab assig~nncnts arc indicativc of thc typc of qucstio~is you sliould ask wlicn examining a scicntific or cnginccring hypothcsis. Your analysis of thcsc qucstions should ~notivatc and guidc thc cxpcrinicnts you will pcrforni, and suggcst how tlic cxpcrimc~ital rcsults will co~ifirm or rcfutc thc liypotlicsis undcr examination. Thc 6.002 prc-lab assiglimcnts will gcncrally a~ialyzc and prcdict thc pcrformancc of an clcc- tronic circuit, and rcsult in prcdictio~is for thc data you will rccord during your in-lab work. As you work througli tlic assignments, you should think about how you could cxpcrilncntally dctcrlninc whcthcr your analysis is corrcct. If you do not scc how thc in-lab work sccks to vcrify your prc-lab work, thcn ncithcr cffort is of valuc cvcn if both arc corrcctly pcrfor~ncd. Finally, as you work on tlic prc-lab assignnicnts, you should takc thc time to ~icatly draw tlic circuits you will build during your in-lab work, and to prcparc any graphs and tablcs ncccssary to organizc data rccording. IT!,-Lah Wr~k Thc notcs you takc during your in-lab work arc siniply a rccord of wliat you did and wliat you obscrvcd. A mi~iinial rccord includcs at lcast tlic following. (1) A labclcd circuit diagram in your lab notcbook adjaccnt to tlic rccordcd data. Thc diagram should includc: voltagc and currcnt sourcc a~nplitudcs and frcqucncics: rcsistor, capacitor, and inductor valucs; scniiconductor and intcgratcd circuit namcs; oscilloscopc and niulti~nctcr co~i~icctions: you think arc important to circuit opcratioli such as and any otlicr co~~ilncnts shielding, coniponcllt tcmpcraturc and so on. You should also notc or skctch your prcdictio~is bcforc you takc a mcasurcnicnt. (2) A rccord of your spccific proccdurcs and mcasurcmc~its. This should includc kcy oscilloscopc and ~nultilnctcr settings, sourcc adjustments niadc wliilc rccordi~ig data, small coniponcnt cha~igcs and so on. You should rccord raw data in your notcbook and intcrprct it latcr, cvcn if latcr nicans only a fcw ~ninutcs latcr bcforc you niovc on to tlic ncxt cxpcrinicnt. For cxa~nplc, if you usc thc voltagc drop across a rcsistor to lncasurc a currcnt you should rccord tlic mcasurcd voltagcs in your lab notcbook and convcrt thcsc nicasurcnicnts to currcnt latcr. If any data is u~icxpcctcdly largc or small? or noisy or noisc-frcc, for cxamplc, or sonic adjustnicnt is particularly largc or scnsitivcl you sliould notc this in your lab notcbook as part of thc data. Finally, i~icludcd in your notcbook should bc all coni~nc~its ncccssary to rccrcatc your cxpcri~ncntal proccdurc. Wavcfornis skctchcd dircctly from tlic oscilloscopc warrant a fcw additional guidclincs. Ncvcr niakc a rough skctch that you will copy into your lab ~iotcbook latcr: cach tinic data is copicd from o~ic lncdiuni to anothcr, ncw crrors and intcrprctations crccp silcntly into thc data. Rathcr, ~icatly skctcli tlic wavcform dircctly into your lab notcbook as accuratcly as possiblc. Sucli skctchcs should bc at lcast as largc as thc oscilloscopc scrccn, and arc no st accuratc if you lct thc rulcd syuarcs of your notcbook graph papcr corrcspo~id to thc rulcd graticulc on tlic oscilloscopc scrccn. (3) Coninicntary about i~iaccuracics in your data. Rccord and plot prcciscly what you scc as accuratcly as possiblc; do not rccord what you cxpcct to scc. Rclatcd to thc accuratc rccording of data is tlic issuc of precision. You 111ust indicatc in your data how prccisc your rcadings arc. Sucli an i~idication can bc as simplc as an cstiniatc of tlic ~ioisc in thc mcasurcnicnt. Wlicn skctcliing
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