PulseVWC-1AcclimaTDR-310WSoilMoisture,EC,&TemperatureProbe

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AcclimaTDR310W:SoilMoisture,TemperatureandElectricalConductivitySensor NOTE:Hub-ReadySensorsRequireaPulseHubBaseToOperate. TheTDR-310WisamodificationtotheAcclimaTDR-315N.Itsshorterrodsallowitfitinstandardrockwoolandcococoirblocks.Itisacompleteintegratedtimedomainreflectometerthatcombinesultra-fastwaveformgeneratinganddigitizingfunctionswithaprecision5pico-secondresolutiontimebaseandhighlysophisticatedwaveformdigitizingandanalyzingfirmwarethatprovidestruetimedomainanalysisofsoil-propagatedwaveforms.Ingreenhouseapplications,itisinsertedhorizontallyintothesidewallofarockwoolororganicsoilblock. Features SDI-12Interface 3-element10cmstainlesssteelwaveguide 5m3-conductorwaterproofcable(standard) Waterproof MeasurementRanges VolumetricWaterContent:0%to100% MediumTemperature:-40to+55degreesC MediumPermittivity:1to100 MediumBulkElectricalConductivity:0to6000µS/cm PoreWaterEC(HilhorstModel):0to55000µS/cm 20%to80%IncidentWaveRiseTime:300ps WaveformDigitizingResolution:5ps IncidentWaveAmplitude:2.3V RecommendedInstallation Therecommendedmethodofinstallationistodigavertical-walledtrenchwithonedimensionatleast12inchesdeep.Thedepthofthetrenchshouldbeacoupleofinchesbelowthedepthatwhichthesensoristobeinstalled.Insertthewaveguiderodshorizontallyintotheverticalwallattheendofthetrench.Theinsertionforcemaybequitesevereinsomesoils.Thiscanbereducedbydeeplywateringthesoilbeforeinstallationand/orbyusingamechanicalforcemultipliertopushthesensorintothesidewall. Incorrectusageofthissensorvoidsourwarranty. It'srecommendedtohaveyourVWCsensorsplacedinthesamepositionthroughoutyourpotstoensureaccurateandconsistentreadings. ClothPots Ifyourclothpotistoothick,youwon'tbeabletogetanaccuratereading.IfyouareusingaclothpotanoticeaconstantVWCpercentage,theprobesmaynotbeabletopenetratedeepenough.IntheseinstanceswesuggesttheVerticalPositioningmentionedbelow. RockWool BlockHydration Beforeinsertingthesensorwaveguideintotheblock,theblockshouldbethoroughlyhydrated. Rockwoolblocksareofteninhomogeneousindensity.Someportionsoftheblockaremoretightlypackedthanotherportions.Thedenservolumestendtobemorehydrophobicandaredifficulttowet.Thelessdensevolumestendtoprovidepreferentialpathsforwatertoflowdownwardthroughtheblockcreatingwetteranddrierregionsthroughoutthematerial.Iftheblocksarenotthoroughlyhydratedtherewillbeairinclusionsintheblockthatmayremaindryforweeks–thuslimitingrootgrowthandcreatingfalseVWCandPWECreadings.EvenafterthoroughlyhydratingtheblockthesaturationwaterintheinclusionsdrainsoutcausingunderestimationoftheVWCreading.Butontheaveragetheseerrorscanbecompensatedmakingthereadingsusefulbutnottotallyaccurate.Arecommendedmethodofhydratingarockwoolblockistoplaceitinabucketcontainingabout12inchesofwater.Theblockwillfloatforaboutaminutethensinkbelowthesurfacewhenitisfullyhydrated.Allowanotherminuteorsoforallbubblingfromtheblocktostop.Thenlifttheblockoutofthewaterbythebottomtoavoidtearingthefibersatthetopoftheblock. VerticalPosition RockWoolandothergreenhousesubstratesaregenerallyusedathighwatercontentlevels–atorabovethefieldcapacityofthematerial.Thiscausesthewaterto‘sink’towardthebottomofthematerial.Measurementstaken1inchfromthetopoftheblockreported20%watercontent.Measurementstaken4”fromthetopoftheblockshowed63%watercontent.Forblockswithlesswatercontentthepositionoftheaveragewatercontentshiftstosomeextent,makingitdifficulttogethighaccuracyreadings.Whatthisinfersisthatthelevelatwhichthesensorwaveguideisinsertedintotheblockiscriticalifconsistentandreasonablyaccuratemeasurementsareneeded. OrganicSubstrates Organicgrowingmediaisusuallyprocuredasloosematerialinbagsorasdried,compressedbricks.Whenusedingreenhouseapplicationsitisnormallyplacedintoplasticbagstoholdittogether.Theloosematerialneedstobecompactedintothegrowingbag,otherwiseitwillnotsupportthesensorwellandairvoidsaroundthewaveguidecouldoccurandcauseerroneousreadings. Hydration Theorganicmaterial,whetherlooseorinbrickform,isplacedintoaplastic‘growbag’.Atypicalbaghasavolumeofalittleover1gallonandhassmallholesinitsbottom.Thebottomfoldisalsonotsealedandwillallowwatertoleakinandout.Placethefilledbagintoabucketcontainingabout8-10inchesofwaterornutrientsolutionandallowittosinktothebottomwhileholdingthetopofthebagtokeepitfromcapsizing.Allowthebagtositinthewateruntilthetopsurfaceisfullyhydrated.Thismayseveralminutesanduptoanhourforcompressedmaterial.Compactthewetmaterialinthebagsothatitisdenseenoughtosupportthesensorwaveguide. Verticalposition Cocoandpeat-basedmaterialshaveahigherfieldcapacitythanrockwoolanddonotexhibitasmuchofawatergradient.Butamildgradientwillformatsaturationlevelsintheorganicmaterial.Henceitisneedfultobeconsistentwiththelevelofinsertionintothebagwall.Theinsertiontoolcanbeusedtoprovidethisconsistencyandtoprovideaflatvoid-freepenetrationintothesoil.Acommonlevelforwaveguideinsertionisabout1.5inchesfromthebottomofthesubstrate. MineralSoils TheTDR310Wwasdesignedforgreenhouseapplications,butitcanbeusedinfieldapplicationsaswell.Itisinherentlyaccurateinallmineralsoiltypeswithoutsoil-specificcalibration. Calibration Thetechnologyusedtomeasurewatercontent(VWC),andelectricalconductivity(EC)makesassumptionsaboutthetypeofmediumitisin,soyouneedtoselectthecorrectcalibrationforyourtypeofsoil.WeoffercalibrationsforSoil(Default),Rockwool,andseveraltypesofCoco.