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41 Daggett Drive, San Jose, CA 95134
Phone: +1 (650) 962 9620 Fax: +1 (650) 962-9647 Email: info@mmr-tech.com Web: www.mmr‐tech.com
GeneralOperation
Sample Preparation
TheMMRSeebeckSystemcanbeusedformeasurementofthe Seebeckcoefficientofa widerangeof
differentconductivesubstances,metals,organicconductors,andsemiconductors.Samplesshouldbein
the form of a thin strip or wire to be installed on the Seebeck Stage. The actual dimensions and the
shapeofsamplesarenotcritical,but shouldbe considerably smallerthan the Seebeckstage itself.We
recommendthatthewidthofthesamplesnotexceed1mm(40mils),and thelength5mm(200mils).
For proper installation of the samples, good electrical and thermal contacts must be provided at both
endsofthesampletotheSeebeckStageAreas(shownbelow).Theunknownsampleshould
beinstalled
to the left or the Seebeck Stage center, and the reference sample to the right. Do not switch these
locations; otherwise you will get completely incorrect results! For attaching the samples to copper
surfaces, one can either use regular soldering alloys, or electrically/thermally conductive cement or
epoxy. The bonding
substance should be able to withstand the temperature range of the proposed
measurements. Materials of high specific resistivity and low thermal conductivity should not be used.
The resistance of the sample plus the bonding material to the Seebeck Stage should be less than
100Kohm.
Installtheunknownsamplefirst,
usingthebondingmaterialofyourchoice,Theworkingjunctionshould
belocate das close aspossible to the slotthat separates the two copper surfaces oftheunknownand
referencesamples(seepage10), Thelocationoftheotherendofthesampleismuchless critical.Ifthe
sample
cannot be formed or folded, attach it at any convenient point on the copperplate which is
common to the unknown and reference samples, and as close to the center as possible. Install the
referencesample in a similar manner.Cutapproximately 5 millimeters (0.2")of the referencematerial
wire supplied
with the System. For the standard Seebeck System version this is a wire of Constantan.
Attachoneendofthewirepiecetothecopperplatewhichiscommontobothsamples.Usethesame
point as for the unknown sample. Theunknownandreferencesamplesshould have direct thermal
contact
in this point. Attach the other end of the reference sample taking into account the same
considerationsasforthetestedsample.Theworkingjunctions ofbothsamplesshouldhavesymmetri cal
locations relative to the stage heater. Finally, using an appropriate fluid, clean the Seebeck Stage of
possiblesurfacecontamination.
WerecommendtheuseofFreon'sand/ormethylorethylalcohol.Any
cleaningmaterialsusedmustbenon‐conductive.
Notice: Be very careful wh ile mounting the samples. Bad electric al or thermal contacts, asymmetrical
locationoftheworkingjunctions,andsurfacecontamination cancauseseriousmeasurementerrors.
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