humidity measurement technology – pros &...
TRANSCRIPT
![Page 1: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/1.jpg)
HumidityMeasurementTechnology– pros&cons
Helping you make a better measurement.
![Page 2: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/2.jpg)
BruceMcDuffee MichaelBoetzkes
WebinarPresenters&HumidityExperts
![Page 3: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/3.jpg)
Agenda&Takeaways
Agenda• Parameterreview• Mechanical• Psychrometer (wet-bulb)• CapacitiveSensors• ResistiveSensors• Chilledmirror• Metaloxide• Applicationcases
Takeaways• Knowwhichsensormakessenseforyourapplication.
![Page 4: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/4.jpg)
Parameteroverview
• RelativeHumidity• Vaporpressure• Dewpoint• Wetbulb
![Page 5: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/5.jpg)
Mechanical
• Usesorganicmaterialsthatchangeinshapeduetochangesinrelativehumidity.
• Shapechangeisconnectedtomechanicallevers,springs,etc.tooutputareading
• Humanhair,catgut,textile,goldbeater’sskin
![Page 6: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/6.jpg)
Mechanical
Pros Cons
Noelectricityneeded Notreliable
Fun Impossible tocalibrate
Onlyaccurate midrange(30to80%RH)
High inhysteresis
Veryslowresponse
Use a mechanical when:• When you need a general idea• If you don’t have much money to spend on humidity measurement• For fun if you’re a humidity geek
Image source - Wikipedia
![Page 7: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/7.jpg)
Psychrometer (wet-bulb)
• Requires2temperaturesensors.• Oneiscoveredwithwetsock.• Airisdrawnoverthetemperaturesensor.
• Thedifferenceordepressionbetweenthetwomeasurementsindicatestheamountofwatervaporpresent. Image source: Wikipedia
![Page 8: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/8.jpg)
Psychrometer (wet-bulb)Pros Cons
Inexpensive($30to$90onAmazon) Requires skillandconsistencytooperatewell
Noproblemwithcondensation Notaccurateinsmallspaces
Easyconversionwithcharts orgraphs Manyvariables=highuncertainty
Use a psychrometer when:• Working with evaporative cooling installations• Large air sample is available• Able to control the variables• Operators remain consistent• No electricity is available (and don’t want to rely on or carry batteries)
Image source: commons.Wikimedia.com
![Page 9: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/9.jpg)
CapacitiveSensors
• Asrelativehumiditychanges,theamountofwatermoleculesabsorbedbythepolymerchangesthedielectricconstantofthecapacitor,varyingthecapacitance.
• Astherelativehumidityincreases,thecapacitanceincreasesalmostinalinearfashion.
Electronic Humidity Sensor
Porous
electrode
Polymeror oxidedlelectriclayer
Electrode
![Page 10: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/10.jpg)
CapacitiveSensorsPros Cons
Accurate andreliable Limitedaccuracy inverydryconditions
Resilienttowater, dustandchemicals Dependentonthemanufacturer
Smallsize Requireselectronicsto generatethesignal
Fast response Hightemp+highRH canaffectcalibration
Widemeasurementrange(0to100%RH) Moreexpensive thanresistive
Widetemperaturerange(-70to+200C)
Use a capacitive sensor when:• Condensation is possible• Dirty environment• Need good performance (accuracy, repeatability, stability, etc.)
![Page 11: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/11.jpg)
ResistiveSensors
• Asrelativehumiditychanges,theresistancechanges.
• IncreaseinRHcauseslowerresistance.
Image source: Sensor Magazine
![Page 12: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/12.jpg)
ResistiveSensors
Pros Cons
Fieldreplaceablewithoutcalibration Notsuitableforextremes
Inexpensive Notresistanttoharsh conditions
Goodformid-rangeRH(20%to90%) Repeatabilityquestionable
Cannot toleratecondensation
Use a resistive sensor when:• conditions are moderate• 20% - 90% RH• Condensation is not expected to occur• Accuracy and repeatability are not critical
Image source: Sensor Magazine
![Page 13: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/13.jpg)
ChilledMirror
• Fundamentalmeasurement• Dewpointtemperatureisdeterminedbythetemperatureofthemirrorwhendeworfrostformsonthemirror.
• Beawareofdewpointvsfrostpoint.• Knowthepressureatthepointofinterest.
Image source: Thunder Scientific
![Page 14: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/14.jpg)
ChilledMirrororCondensationHygrometer
Pros Cons
Lowuncertainties;(+/- .1Ck=2) Expensive comparedtoothertechnologies
Highlystable Requiresverycleanenvironment
Broadrange(-100Cto+100C) High levelofmaintenance
Fundamentalmeasurement Requiresaskilled, trainedoperator
Airflow throughsensinghead
Use a chilled mirror when:• Low uncertainty and high stability are a requirement (Lab, R&D)• Measurement environment is clean and controlled• You have a lot of money and you don’t know what to do with it.• Not recommended for inline or field applications.
![Page 15: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/15.jpg)
MetalOxide
• AluminumOxide(Al2O3)mostcommon
• Watervaporadsorbstooxide• Conductivityvarieswithamountofwatervapormolecules
• Givesanabsolutemeasure• Needpressureandtemperatureforconversions
Image source: Sensor Magazine
![Page 16: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/16.jpg)
MetalOxide
Pros Cons
Excellentforverydryconditions(aslowas-100C)
Slowresponse tochanges
Very smallfootprint Largecalibrationshiftsfromwetair
Requires numerouscalibrations
Calibrationisusuallyveryexpensive
Notstableovertime
Use a metal oxide when:• Very dry, very clean air/gas• For dew point temperature < -70C• Stable, uneventful air streams• Measuring trace moisture in absolute terms (ppm, mixing ratio, p)
![Page 17: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/17.jpg)
SummaryofTechnologies
Othertechnologies:• Spectroscopy• Colorchangingchemicals• Saturatedlithiumchloride• Electrolytic• Acoustic• Adiabaticexpansion• Gravimetric• Andmore
1. Mechanical2. Psychrometer (wet-bulb)3. CapacitiveSensors4. ResistiveSensors5. Chilledmirror6. Metaloxide
![Page 18: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/18.jpg)
Comments&Questions
Pleasetypeyourquestionsintothechatboxatthelowerleftportionofyourscreen.
![Page 19: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/19.jpg)
TakeawaysforaBetterMeasurement
![Page 20: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/20.jpg)
ChoosetheBestTechnologyforYourApplication
Glovebox whereyouhavetomaintain5ppmwatervapor.
• Temperatureis23C• Airisveryclean• Minimalchanceofcondensation• Needveryhighaccuracy,reliabilityandstability.
• Moneyisnoobject
Image source: Flickr: Glovebox; Author: Idaho National Laboratory
![Page 21: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/21.jpg)
ChoosetheBestTechnologyforYourApplication
• Compressedairsystem• Desiccantdryers-40Cdewpoint• 90psigoperatingpressure• Industrialenvironment• Condensationlikelyatsomepointinthesystem(unreliabledryers)
• Needinlinemeasurementatcriticalpointsofuse
• Lowbudgetoperation
![Page 22: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/22.jpg)
ChoosetheBestTechnologyforYourApplication
Cleanroom• Temperatureis23C• Humidity40%• ParticlesizeClassISO3• Airpressuredifference• Airchangerate• Airflowvelocity
![Page 23: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/23.jpg)
SummaryofChoosingtheCorrectInstrument
1. Measurementenvironment2. Performancerequirements3. Parameterrequired
![Page 24: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/24.jpg)
Comments&Questions
Ifwedon’tgettoyourquestiontoday,we’llrespondviaemailafterthewebinar.
![Page 25: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/25.jpg)
Rotronic Academy
• Resourcesforhumiditymeasurement• ResourcesforcGMPmapping• Resourcesforenvironmentalmonitoring
www.rotronic-usa.com/academy
![Page 26: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/26.jpg)
NextWebinarHowtoMapaWarehouseThursday,December1st1:00PMESTwww.rotronic-usa.com/webinars
![Page 27: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/27.jpg)
Helpingyoumakeabetterhumiditymeasurement– andmore.
Transmitters,meters,OEMprobesforhumidity,dewpoint,CO2,differentialpressure,andmore.
NEW!Rotronic MonitoringSystemwww.rotronic-usa.com/RMS
![Page 28: Humidity Measurement Technology – pros & conscontent.rotronic-usa.com/rs/479-NTR-434/images/Rotronic... · 2016. 10. 27. · Humidity Measurement Technology – pros & cons Helping](https://reader035.vdocuments.us/reader035/viewer/2022071515/613734110ad5d206764877e7/html5/thumbnails/28.jpg)
Thankyou!email:[email protected]:www.rotronic-usa.com
On-demandwebinarsandregistrations:www.rotronic-usa.com/webinars