ultrasonic anemometers - helsinki

www.helsinki.fi/[email protected]

DepartmentofPhysics– AtmosphericDivision/EddyCovariance– setup,design,selection,calibration

Ultrasonicanemometers:

- Campbell- CSAT3- userfriendly;

- needstobeorientatedintomain

winddirection;

- noneedfor“crosswind“correction;

- Gill- R3(3-axis),HS-50/100- doesnotneedtobeorientatedtowardsNorth;

- angleofattackcorrections;

- METEK–USA1- currentlytheonlyheatedoneonthemarket

- noneedtobeorientatedtowardsNorthbutmakeslifeeasier;

- needfor“crosswindcorrection”;

www.gillinstruments.com



InfraRed gas analysers (IRGA)

- Closed-pathgasanalyser:

- LI-6262(CO2/H2O)

- requiresanexternalpump;

- requiresconstantreferencegassupply;

- frequentcalibrationchecks/calibrationneeded;

- tubeattenuation;lagtime;

- LI-7000(CO2/H2O)

- requiresanexternalpump;

- requiresconstantreferencegassupply;

- frequentcalibrationchecks/calibrationneeded;

- tubeattenuation;lagtime;www.licor.com




- Closed-pathgasanalyser:

- CampbellSci.CPEC200(compact3D&CO2/H2O)

- lowpowerconsumption;

-consistsofaCSAT3AandtheEC155IRGA;

- includesasamplepump;

- datarecordingontotheCR3000datalogger;

- notubeattenuation;lagtime;www.campbellsci.co.uk




- Open-pathgasanalyser:

- LI-7500(CO2/H2O)

- noneedforexternalpump;

- lowpowerrequirement;

- noneedforreferencegas;

- userfriendly;lightweight;

- notimelag;




- Open-pathgasanalyser:

- CampbellSci.IRGASON(3DandCO2/H2O)

- noneedforexternalpump;



- userfriendly;lightweight;

- notimelag; www.campbellsci.co.uk




- Closed-path(enclosed)gasanalyser:

- LI-7200(CO2/H2O)

- comeswithitsownpump;



- userfriendly;

- ownloggingsystem;

- lightweight;

- tubeattenuation;lagtime;



Laserspectroscopy

- Closed path cavity ring down

- Picarro (CO2/H2O/CH4,etc.)- requiresanexternalpump;

- needsmainspower;

- noneedforreferencegas(referencecapsuleinside);

- tubeattenuation;www.picarro.com



Laserspectroscopy

- Closed path integrated cavity outputICOS

- LosGatos(CH4,CO,CO2,N2O,H2Oetc.)- requiresanexternalpump;- needsmainspower(amassivegeneratordoesittoo);- noneedforreferencegas;- tubeattenuation;

www.losgatos.com



Laserspectroscopy

- Openpath multipass cell instrument

-LI-7700(CH4)- noneedforexternalpump;- lowpowerrequirement;- noneedforreferencegas;- userfriendly;notimelag;



Site establishment(Quality Assessment/Quality Control)

- purposeofstudyandchoiceofecosystem- enduserofdata;

- sitelocation,landownershipandaccess- arewemeasuringintherightlocation?Pilotproject;

- lengthofdatacollection(campaign/permanent)- enduserofdata;purposeofmeasurement;

- dataexpectations(fluxmagnitude)- whyarethemeasurementscarriedout?Useofcorrectmeasurementprotocols;

- additionalmeasurements- meteorological(atmosphericandsoil)arerequired;



Powerrequirementsandsupply(gettingdowntobusiness...)

- Short-/long-termdatacollection;- Continuousrecordingorsamplingofdata;- 5V,12V,24V,220V/110Vrequired?

- Carbatteries,solarpanels,windenergy,generator,mainspower;



Powersupply

- Carbatteries(additionalpowersource):- frequentreplacement;- idealforshorttermstudies;- easytousebutbloodyheavyifneedstobecarriedaround;

- Solarpanels:- sitelocation;- adequatesupplyallyearround?- chargecontrollerandbatteryunits;- easytouse(onceyouknowhowtheywork);



Powersupply

- Mainspower:- Sitelocation;- distancetonearesttransformer(Voltagedrop);- easytouse(andconverttolowerVoltage);- Nolimitationofsupplytoinstrumentsallyearround;- Expensiveifnewlyestablished;- Runningcosts;- powersurges(?)



Powersupply

- Windenergy:- Sitelocation;

- adequatesupply?- chargecontrollerandbatteryunits;- location(footprintlocation);

- easytouse;

- Fuelgenerator:

- location(footprintlocation);- frequentrefuellingofpetrol,hydrogen,diesel,etc.;

- chargecontrollerandbatteryunits;



Siteinfrastructure

- Ecosystemrelevantstructure;- Access;- Safety;- Protection;- Housing;- Datamanagement;- Set-upselection



Decisiontime

- Open- vs.closed-pathanalyser;- dataquality(dry/wet);- powerrequirements(mains/batteries);- cleaning(filter/openwindow)- referencegasrequirement(gascylinders);- necessityofapump;- datastorage- costs(purchase&runningcosts);



Set-upexamples



Andwhatnow???

- Oncesiteisupandrunning…- Calibrationchecks;

- frequentdatacontrol(toavoidinstrumentdrift,powerfailure,filterclogging,pumpfailure,underestimateddatastorage,dropouts,etc.)

- instrumentandsitemaintenance;- (referencegaschecks);

- Conclusion:thecleaneryoukeepyoursystem

andthebetteryoumaintainyousystemthehigherqualitydatayouwillhave(technicalpointofview)!



Timetogohome…

“Scientificruins”

ultrasonic anemometers - helsinki

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