water activity - lab equip activity, by definition,is the measurement of water vapor pressure...
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• DetermineproductqualitywithROTRONICAwproducts
• ROTRONICAwdevicesforlaboratoryandportablesystems
• SpecialUSBprobesfordirectPCconnection
• AwQuickfunctionprovidesaccurateAwreadings
withinafewminutes
• Laboratorybench-topindicatorreadsupto4probes
simultaneously
• Largechoiceofprobesfordifferentapplications
• Easytocalibrateandmaintain
FAST AND PRECISE WATER ACTIVITY MEASUREMENTS.INTRODUCING AIRCHIP DIGITAL TECHNOLOGY.
WATER ACTIVITY MEASUREMENT
WATER ACTIVITY
ROTRONIC offers a complete range of water activity products. Use any combination of probes to fit your application.
ROTRONIC products are freely combinable and can be perfectly adapted to your needs. The devices are accurate and
are characterized by their high efficiency, exchangeability, and ease of calibration.
BE PRECISE:ADVANTAGES AT A GLANCE.
What is water activity?Wateractivity,bydefinition,isthemeasurementofwater
vaporpressuregeneratedby the freeornon-chemically
bound water in foods and other products. The bound
waterandmoisturecontentcannotbemeasureddirectly
withthismethod.TheAwvalue(range:0.00...1.00aw)is
animportantindicatorfortheshelflifeoffoods,pharma-
ceuticalandcosmeticproductsanditstronglyinfluences
theoccurrenceandgrowthofmicroorganisms.
Water activity Contaminantaw=0.91…0.95 Manybacteriaaw=0.88 Manyyeastsaw=0.80 Manymildewsaw=0.75 Halophilebacteriaaw=0.70 Osmiophileyeastsaw=0.65 Xerophilemildew
WATER ACTIVITY
Why measure water activity?Thefreewaterinaproductinfluencesitsmicrobiological,chemicalandenzymaticstability.Thisisofgreatimportanceespeciallyforper-
ishableproductssuchasfoods,grains,seedsandparticularlyforpharmaceuticalpowdersandtablets.Ifthereistoomuchfreewater,the
foodisspoiled.Toolittlewatercanadverselyaffectproductproperties.
Thetableshowstypicalgrowththresholdsbelowwhichthespecifiedorganismcannot
reproduceandthereforespoiltheproduct.Thereforewateractivityhasasignificantim-
pactontheshelflifeofaproduct.
Themeasurementofwateractivityalsoprovidesusefulinformationaboutcharacteristics
suchascohesion,storability,agglomerationorflowpropertiesofpowdersandtabletsor
theadhesionofcoatings.
Aw Quick functionality for very fast and precise resultsRegularAwmeasurementtakesaboutanhourtodetermineexactAwvalue.TheROTRONICAwQuickfunctionallowsAwmeasurement
resultsin5minutesorless.Thefunctionisnearlyaspreciseastheregularmeasurementmethod.Itrequiresanenvironmentwithstable
temperaturesvariationswhichismostlygiveninlaboratoryandindoorapplications.Thebench-topunitHygroLabC1,thehandhelddevice
HP23-AW-AandthesoftwareHW4-P-QUICK-VxallincludetheAwQuickcapability.
Foradditionaltimesavingupto4probescanbeconnectedtotheHygroLabC1.Forapplicationswithalargeamountofmeasurementsup
to64USBprobescanbedirectlyconnectedtotheHW4softwarewhichalsoprovidestheAwQuickfunction.
AllmeasurementresultsaresavedinlogfileseitherdirectlyinthedeviceorviatheHW4softwareonthePC.
Software calibrationIt'sessentialthatinstrumentshaveregularcalibrationcheckstraceabletonationalstand-
ardsensuringoptimumperformanceatalltimes.HW4softwareprovidesconvenient,easy
tousecontrolofthecalibrationprocess,andifrequired,thesensoradjustmentsequence:
• Fullsoftwarecontrolofcalibrationoradjustmentsequenceandtiming
• Singleormultiplepointsadjustment/calibration
• Preciseadjustmentto0.001Aw(0.1%RH)and0.1K
• Automaticgenerationofadjustment,calibrationandconfigurationreports
• Pre-configuredtosuitROTRONICSCScertifiedhumiditystandards
• Userconfigurablecalibrationandadjustmentprocess
WATER ACTIVITY
What is equilibrium relative humidity?Equilibriumrelativehumidity(ERH)isthevalueofrelativehumidityintowhichahygroscopicproductcanbeplacedwherenonetexchangeof
moisturebetweentheproductandthesurroundingenvironmentcantakeplace.Itisexpressedonascaleof0…100%.ERHistypicallyusedinthe
paperandpharmaceuticalindustries,butcanbeappliedtoalmostanyproductthatissensitivetomoisture,orwherethepresenceofmoisture
canaffectproducthandling.
Aw or ERH?BothAwandERHareanexpressionoftheamountoffreewatervaporpresentonaproduct,bothatitssurfaceandwithinitsstructure,andare
practicallythesamemeasurementexpressedinaslightlydifferentway.Throughoutthisbrochurewewillrefertowateractivity,butthiscanbe
interchangedwithERH.Wherespecified,ROTRONICproductsoffertheusertheoptiontoselectdisplayunitsasAwor%RH.
What is water content?Watercontent,whenreferring toasolidmaterial, isanexpressionof thepercentageof thematerialsweightwhich iswater (both in liquidor
gaseousphase);usuallyreferredtoas‘percentmoisturecontent’.Thistermiswidelyusedinmanyareasofindustry.
Water activity or water content?There is frequently confusion between water activity and water content
measurements. In many industries, water content is used to control the
amountofwaterpresentinaproductforquantitativereasons.Forexample,
ifaproduct issoldbyweight,controlling itswatercontentmaybeuseful
in maintaining product quality, but can also impact on profitability (more
waterequalsmoreprofit).Wateractivity ismoresignificant forqualitative
considerations such as product stability, shelf life (e.g. microbiological &
enzymaticstability,aroma retention),handlingcharacteristics (e.g.agglo-
meration of powders), physical properties (e.g. dimensions of paper) and
chemicalstability(e.g.pharmaceuticals).Wateractivityandwatercontent
canberelatedbyagraphcalledaSorptionIsotherm(seediagram)soifthe
user has the ability to measure both parameters, the relationship can be
definedandeachparameterderivedfromtheother(interpolation).Inpractice,thesorptionisothermmaybeimpracticaltouse,because,notonly
doestherelationshipbetweenAwandmoisturecontentchangewithtemperatureofmeasurement,butalsoanyvariationsinthematerialcompo-
sitionhasamodifyingeffect.Thisisespeciallythecasewithproductsofnaturaloriginsuchasfoodandpaper.Theusershouldthereforedecide
whichparameterofmeasurementisbestsuitedtotheirproductsandprocesses.Forqualitycontrolpurposesmoisturecontentlimitsareeasily
convertedtowateractivitylimitsbyverysimplecomparativetests.Wateractivitymeasurementoffersanon-destructive,easy-to-usemeasurement
inawiderangeofconvenientconfigurationsforbothlaboratoryandon-siteuse.
WATER ACTIVITY
Order code HygroLab C1
Probeconnections 4xHC2stationprobeorHC2insertionprobe
Parametersshown Aw,%RH,°C,°F
AwQuickfunction IntegratedandviaHW4softwareHW4-P-QUICK-Vx(inshipmentincluded)
Calculations Allpsychrometriccalculationsavailableoruserdefinedcalculations
Probeadjustment Singleormultiplepointforrelativehumidity&temperature
Oneortwopointtemperature
Memory 4x500Awvalues(2,000Awvalues)
Measurementinterval 1s
Start-uptime 3s
Powersupply 8…16VDCwithACadapter
Interfaces EthernetandUSB
HW4compatible V3.1andhigher
Rangeofapplication -10…60°C(14…140°F)/0…1Aw/0…100%RH
LCD 3-linealphanumericwithtrendindicators
Clock Realtimeclockprovidesatimestampforeverymeasurement
Currentconsumption Max.120mA(12VDC,backlightON,4probesconnected,Ethernet)
IPprotectionclass IP21
CE/EMCconform EMC2008/108/EG
FDA/GAMP FDA21CFRpart11/GAMP5
Dimensions/Weight 225x170x70mm/1100g
Material Aluminum,ABS-757
HygroLab C1
Laboratory applicationROTRONICprovidesahigh-endlaboratorydevice–theHygroLabC1–for
wateractivitymeasurementswithuptofourprobes.Connectstation
probesandinsertionprobesformeasuringwateractivityincheese,meat,
tobacco,buildingmaterials,animalfeed,pharmaceuticalsproductsand
muchmore.
Validated softwareEasy-to-useandintuitive,thelaboratorygradeindicatorcanbeusedby
anyone.HW4runningonaPCprovidesremotemonitoringwithcharting
anddatarecordingfunctions.
Features• 4inputchannelsforHC2stationprobesorHC2insertionprobes
canbeconnectedformeasurementofwateractivity,relativehumidity
andtemperature
• AwQuickfunctionforfastmeasurementresults(typically4-5minutes)
• Audiblealarmtoindicatecompletedmeasurement
• Savesupto2,000datarecordswith%RH,°C/°F,dateandtime
PS-40
HC2-AW
WP-40
AW-KHS
WATER ACTIVITY
Order code HC2-AW
Probetype MeasurementprobewithUARTinterface
Connection ViaUART,1mcable
Forusewith HygroLabC1,HP23-AW-A
Accuracyat23°C±5K(73.4°F) ±0.008Aw/±0.8%RH/±0.1K
Temperaturedependence 0.001K/K,0.0002aw/K
Sensor HYGROMER®WA-1/Pt-100,1/3DINClassB
Calculations Deworfrostpoint
Longtermstability <1%RH/year
Powersupply Viadisplayinstruments
Rangeofapplication -40…85°C(-40…185°F)/0…100%RH
Filtertype Wiremeshfilterwith20…25μmporesize
Responsetimet63 <20s
Measurementinterval 1s
Start-uptime 1.5s
IPprotection IP20
CE/EMCconformity EMC2008/108/EG
FDA/GAMP FDA21CFRpart11/GAMP5
Dimensions/Weight Ø68x60mm/600g
Material Stainlesssteel,aluminum
Aw station probesThestationprobesaredesignedforusingwithHygroLabC1
orHygroPalmHP23-AW-A.Measurementofwateractivitywiththis
digitalprobeisprecise,fastandeasy.Theprobecanbecalibra-
tedwiththeHygroLabC1orviatheHW4software.Minimized
internalvolumeofthesensorchamberensuresfastequilibrium
withallproducts,andanallmetalconstructionensuresgood
temperaturestabilityduringmeasurements,withstainlesssteel
usedonallcriticalsurfaces.Sampleholders,samplecontainers
andasealingmechanismaredetailedinaccessories.
Typical accessoriesSampleholders: WP-14-S,WP-40,WP-40TH
Disposablesamplecontainer: PS-14(14mmdeep),PS-40(40mmdeep)
Note: Ordersamplecontainersseparately.
Sampleholderscanalsobeusedascalibrationdevice.
Typical accessories
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