Hobo MX2306 User manual

HOBO®MXSoilMoisture(MX2306)and
MXSoilMoistureandTemperature(MX2307)DataLoggerManual
26456‐A
TheHOBOMXSoilMoisture(MX2306)andHOBOMXSoilMoistureandTemperature(MX2307)
dataloggersmeasuresoilmoistureandtemperatureinnumeroussoiltypes,includinghigh
salinityandsandysoil.TheseBluetooth®‐enabledloggersaredesignedforwireless
communicationwithaphone,tablet,orcomputer.UsingtheHOBOconnect®app,theusercan
easilyconfiguretheloggerandthendownloadloggeddatatovieworexportforfurther
analysis.Theloggerscancalculateminimum,maximum,average,andstandarddeviation
statisticsandbeconfiguredtoindicatealarmsatuser‐specifiedthresholds.Theloggersalso
supportburstlogging,inwhichdataisloggedatafasterintervalwhensensorreadingsare
aboveorbelowcertainlimits.
Specifications

MeasurementRange
(selectoneat
configuration)
0.00to0.64m³/m³VWCinmineralsoils
0.00to0.70m³/m³VWCinsoillessmedia
ApparentDielectricPermittivity:1(air)to80(water)
Accuracy*±0.031m³/m³typicalinmineralsoilsthathavesolutionEC<8
dS/m
±0.051m³/m³typicalinsoillessmedia
ApparentDielectricPermittivity:+/‐1Ɛafortherange1to40
(soilrange);+/‐15%forover40
Resolution0.001m³/m³
ApparentDielectricPermittivity:0.1Ɛa
DielectricMeasurement
Frequency
70MHz
VolumeofInfluence430ml
Percentof
FieldCapacity
(forVWCmeasurements
only)
Range:0to200%
Resolution:0.1%

TemperatureSensor
(MX2307)

Range‐40to100°C(‐40to212°F),withtipandcableimmersioninfresh
waterupto50°C(122°F)foroneyear
Accuracy±0.25°Cfrom‐40to0°C(±0.45from‐40to32°F)
±0.2°Cfrom0to70°C(±0.36from32to158°F)
±0.25°Cfrom70to100°C(±0.45from158to212°F)
Resolution0.04°C(0.072°F)
Drift<0.01°C(0.018°F)peryear
ResponseTime3minutesinairmoving1m/s;20secondsinstirredwater
4minutesinairmoving1m/swithRS3‐BSolarRadiationShield
Logger
OperatingRange‐25°to60°C(‐13°to140°F)
RadioPower1mW(0dBm)
TransmissionRangeApproximately30.5m(100ft)line‐of‐sight
WirelessDataStandardBluetoothLowEnergy(BluetoothSmart)
LoggingRate1secondto18hours
LoggingModesFixedinterval(normal,statistics)orburst
MemoryModesWrapwhenfullorstopwhenfull
StartModesImmediate,pushbutton,date&time,ornextinterval
StopModesWhenmemoryfull,pushbutton,date&time,orafteraset
loggingperiod
HOBOMX2306and
MX2307DataLoggers
Models:
SoilMoisture(MX2306)
SoilMoistureand
Temperature(MX2307)
IncludedItems:
Screws
Cableties
RequiredItems:
HOBOconnectapp
Mobiledevicewith
BluetoothandiOS,
iPadOS®,orAndroid™,ora
Windowscomputerwitha
nativeBLEadapteror
supportedBLEdongle
Accessories(sold
separately):
Solarradiationshield
(RS3‐Bforusewith
MX2307)
Soilmoistureverification
clip(TEROS‐CLIP)
Replacementbattery
(HRB‐2/3AA)


MX2307ModelShown

HOBOMXSoilMoisture(MX2306)andMXSoilMoistureandTemperature(MX2307)DataLoggerManual
1‐508‐759‐9500(U.S.andInternational)2www.onsetcomp.com
1‐800‐LOGGERS(U.S.only)
TimeAccuracy±1minutepermonth0°to50°C(32°to122°F)
BatteryType2/3AA3.6Voltlithium,userreplaceable
BatteryLife2years,typicalwithloggingintervalof1minuteandBluetooth
AlwaysOnenabled;5years,typicalwithloggingintervalof1
minuteandBluetoothAlwaysOndisabled.Fasterlogging
intervalsandstatisticssamplingintervals,burstlogging,
remainingconnectedwiththeapp,excessivedownloads,and
pagingmayimpactbatterylife.
Memory110,000measurements,maximum(472KB)
FullMemoryDownload
Time
Approximately60seconds;maytakelongerthefurtherthe
deviceisfromthelogger
DimensionsLoggerhousing:10.8x5.08x2.24cm(4.25x2.0x0.88in.)
Soilmoisturesensor:7.5x5.1x2.4cm(2.95x2.02x0.95inches)
Soilmoisturesensorneedlelength:5.4cm(2.13inches)
Soilmoisturesensorneedlediameter:0.32cm(0.13inches)
Temperaturesensor(MX2307)diameter:0.53cm(0.21in.)
Sensorcablelength:2m(6.56ft)
WeightMX2306:229g(80oz)
MX2307:267g(94oz)
MaterialsLogger:Acetal,siliconegasket,stainless‐steelscrews
SoilMoistureSensor:ASAplasticbodywithpolyurethaneepoxy
fillingandstainless‐steelpins
TemperatureSensor(MX2307):Stainless‐steelwaterprooftip
Cable:PVC,UVresistantandrodentrepellent(soilmoisture
sensorcable)
EnvironmentalRatingLogger:‐25to60°C(‐13to140°F);weatherproof;NEMA6and
IP67
SoilMoisturesensorandcable:‐40to60°C(‐40to140°F)
Temperaturesensorandcable(MX2307):Immersioninwaterup
to50°C(122°F)for1year

TheCEMarkingidentifiesthisproductascomplyingwithall
relevantdirectivesintheEuropeanUnion(EU).

TheUKCAmarkingidentifiesthisproductascomplyingwithall
relevantdirectivesintheUKDeclarationofConformity.
 Seelastpage
*Foradditionalaccuracy,t hesensordatacanbepost‐calibratedforaparticularsoilbyapplyingacalibrationequation
tothedataexportedfromtheapp.

LoggerComponentsandOperation
 
MountingHoles:Usetheholesatthetopandbottomofthe
loggertomountit(seeDeployingandMountingtheLogger).
AlarmLED:ThisLEDblinksredevery4secondswhenanalarm
istripped(unlessShowLEDisdisabledasdescribedin
ConfiguringtheLogger).
StatusLED:ThisLEDblinksblueevery4secondswhenthe
loggerislogging(unlessShowLEDisdisabledasdescribedin
ConfiguringtheLogger).Iftheloggeriswaitingtostartlogging
becauseitwasconfiguredtostart“OnButtonPush”orwitha
delayedstart,itwillblinkevery8seconds.
StartButton:Pressthisbuttontowakeupthelogger;boththe
alarmandstatusLEDswillblink.Oncetheloggerisawake,
pressthisbuttontomoveittothetopofthedeviceslistinthe
app.Pressthisbuttonfor3secondstostartorstopthelogger
whenitisconfiguredtostartorstop“OnButtonPush”(see
ConfiguringtheLogger).BothLEDswillblinkfourtimeswhen
youpressthebuttontostartorstoplogging.Pressthisbutton
for10secondstoresetapassword(seeSettingaPassword).
MX2307modelshown
AlarmLED
Mounting
Holes
StartButton
ExternalSensor
StatusLED

HOBOMXSoilMoisture(MX2306)andMXSoilMoistureandTemperature(MX2307)DataLoggerManual
1‐508‐759‐9500(U.S.andInternational)3www.onsetcomp.com
1‐800‐LOGGERS(U.S.only) 
ExternalSensor:Thisisthesoilmoisture(andtemperature
sensorinMX2307model)attachedtothebottomofthelogger.
SoilMoistureSensorComponentsand
Operation
Thesoilmoisturesensormeasuresthevolumetricwater
content(VWC)ofsoilusingstainless‐steelneedles.Aferrite
corepositionedonthesensorcable7.6cm(3inches)away
fromthesensorheadisusedtoisolatethesensorfromany
interferencesinthesystem.Thismitigatesanypotentialnoise
fromthesystemonthemeasuredsensordata.
Important:Donotattachanythingtothesectionofthe
cablebetweenthesensorheadandtheferritecoreas
thismayinfluencethemeasurements.

TheVWCmeasurementsensitivityiscontainedwithina430mL
volumeroughlydepictedinthefollowingfigures.Notethatthe
sensorismostsensitivetothemoistureintheareaclosestto
theneedles,soitiscriticalthattherearenoairgapsaroundthe
needles.





DownloadingtheAppand
ConnectingtoaLogger
Installtheapptoconnecttoandworkwiththelogger.
1. DownloadHOBOconnecttoaphoneortabletfromtheApp
Store®orGooglePlay™.
DownloadtheapptoaWindowscomputerfrom
www.onsetcomp.com/products/software/hoboconnect.
2. OpentheappandenableBluetoothinthedevicesettingsif
prompted.
3. Pressthebuttonontheloggertowakeitup.
4. TapDevicesandthentaptheloggerintheapptoconnect
toit.
Iftheloggerdoesnotappearorifitishavingtrouble
connecting,followthesetips:
Makesuretheloggeris“awake”bypressingthestart
button.ThealarmandstatusLEDswillblinkoncewhen
theloggerwakesup.Youcanalsopressthebuttona
secondtimetobringtheloggertothetopofthelistif
workingwithmultipleloggers.
Makesuretheloggeriswithinrangeofthemobiledevice
orcomputer.Therangeforsuccessfulwireless
communicationisapproximately30.5m(100ft)withfull
line‐of‐sight.
Ifthereareseveralloggersinthearea,movethelogger
toalocationwithfewerloggers.Interferencecan
sometimesoccurwhennumerousloggersareinone
location.
Ifyourdevicecanconnecttotheloggerintermittentlyor
losesitsconnection,moveclosertothelogger,within
sightifpossible.
Iftheloggerappearsintheapp,butcannotbe
connected,closetheappandthenpowerdownthe
devicetoforcethepreviousBluetoothconnectionto
close.
Oncetheloggerisconnected,youcan:
Tapthis:Todothis:

Selectloggersettingsandsavethemontothe
loggertostartlogging.SeeConfiguringthe
Logger.

Readout(offload)loggerdata.SeeReadingOut
theLogger.
WARNING:Riskof
personalinjuryis
present.Sensorneedle
pointsareextremely
sharpandwillpuncture
skin.Handlewithcare.
Ferritecore

HOBOMXSoilMoisture(MX2306)andMXSoilMoistureandTemperature(MX2307)DataLoggerManual
1‐508‐759‐9500(U.S.andInternational)4www.onsetcomp.com
1‐800‐LOGGERS(U.S.only) 
Tapthis:Todothis:

Startloggingiftheloggerwasconfiguredtostart
withabuttonpush.SeeConfiguringtheLogger.

Stoptheloggerfromrecordingdata(this
overridesanyStopLoggingsettingsdescribedin
ConfiguringtheLogger).

IlluminatetheloggerLEDsfor4seconds.

Setaloggerpasswordthatwillberequiredif
anothermobiledeviceattemptstoconnecttoit.
Toresetapassword,pressthebuttononthe
loggerfor10secondsortapandtapReset.

Marktheloggerasafavorite.Youcanthenfilter
thelistofdevicestoonlyshowloggersmarkedas
favorites.

Updatethefirmwareonthelogger.Alogger
readoutwillbecompletedautomaticallyatthe
beginningofthefirmwareupdateprocess
Important:Beforeupdatingthefirmwareon
thelogger,checktheremainingbatterylevel
andmakesureitisnolessthan30%.Make
sureyouhavethetimetocompletethe
entireupdateprocess,whichrequiresthat
theloggerremainsconnectedtothedevice
duringtheupgrade.

Note:Tappingthisiconisonlyrequiredwhenusingthe
apponaniPhone®,iPad®,orAndroiddevice.
ConfiguringtheLogger
Usetheapptosetupthelogger,includingselectingthelogging
options,configuringalarms,andothersettings.Thesesteps
provideanoverviewofsettingupthelogger.Forcomplete
details,seetheappuser’sguide.
1. Pressthebuttonontheloggertowakeitup.
2. Intheapp,tapDevicesandtaptheloggerintheappto
connecttoit.Ifyouareworkingwithmultipleloggers,you
canpressthebuttonontheloggerasecondtimetobringit
tothetopofthelist.
3. Taptoconfigurethelogger.
4. TapNameandtypeanameforthelogger(optional).Ifno
nameisselected,theloggerserialnumberisusedasthe
name.
5. TapGrouptoaddtheloggertoagroup(optional).TapSave.
6. TapLoggingIntervalandchoosehowfrequentlythelogger
willrecorddataunlessoperatinginburstloggingmode(see
BurstLogging).Note:Ifanalarmisconfigured,thelogger
willusetheloggingintervalthatwasselectedastherateto
checkforalarmconditions(alarmsarenotavailableifburst
loggingisconfigured).SeeSettingupAlarmsformore
details.
7. TapStartLoggingandselectwhenloggingwillbegin:
Now.Loggingwillbeginimmediatelyafterconfiguration
settingsareloadedonthelogger.Thedatawillstartwith
thisindeterminedtimeandattheselectedlogging
intervalfromthere.
OnNextLoggingInterval.Thisisthemostcommonstart
option.Loggingwillbeginatthenextevenintervalas
determinedbytheselectedlogginginterval.Forexample,
ifa10‐minuteintervalisselected,thedatawillstartat
thenexteven10‐minutetime.
OnButtonPush.Loggingwillbeginoncethebuttonon
theloggerispressedfor3seconds.
OnDate/Time.Loggingwillbeginonadateandtimeyou
specify.Selectthedateandtime.
TapSave.
8. TapStopLoggingandselecttheoptionsforwhenlogging
willend.
a. Chooseoneoftwomemoryoptions:
WhenMemoryFills.Theloggerwillcontinuerecording
datauntilthememoryisfull.
Never(WrapWhenFull).Theloggerwillcontinue
recordingdataindefinitely,withnewestdata
overwritingtheoldest.Thisoptionisnotavailableif
theLoggingModeissettoBurst(seeBurstLogging).
b. SelectOnButtonPushtobeabletostoploggingby
pushingthebuttonontheloggerfor3seconds.
c. Selectoneofthefollowingtimeoptionsforwhentostop
logging:
Never.Selectthisifyoudonotwanttostopthelogger
atanypredeterminedtimeframe.
OnDate/Time.Selectthisifyouwanttheloggerto
stoploggingonaspecificdateandtime.Selectthe
dateandtime.
After.Selectthistocontrolhowlongtheloggershould
continueloggingonceitstarts.Choosetheamountof
timetheloggerwilllogdata.Forexample,select30
daysifyouwanttheloggertologdatafor30daysafter
loggingbegins.
d. TapSave.
9. TapLoggingMode.Selecteitherfixedorburstlogging.With
fixedlogging,theloggerrecordsdataforallenabledsensors
and/orselectedstatisticsattheloggingintervalselected
(seeStatisticsLoggingfordetailsonchoosingstatistics
options).Inburstmode,loggingoccursatadifferent
intervalwhenaspecifiedconditionismet.SeeBurst
Loggingformoreinformation.TapSave.
10. EnableordisableShowLED.IfShowLEDisdisabled,the
alarmandstatusLEDsontheloggerwillnotbeilluminated
whilelogging(thealarmLEDwillnotblinkifanalarmtrips).
YoucantemporarilyturnonLEDswhenShowLEDis
disabledbypressingthebuttonontheloggerfor1second.
11. EnableordisableBluetoothAlwaysOn.IfBluetoothAlways
Onisenabled,theloggerwill“advertise”orregularlysend
outaBluetoothsignalforthephone,tablet,orcomputerto
findviatheappwhileitislogging,whichusesbattery
power.WhenBluetoothAlwaysOnisdisabled,thelogger
willonlyadvertiseduringloggingwhenthebuttononthe
>
>
>
>
>
>

HOBOMXSoilMoisture(MX2306)andMXSoilMoistureandTemperature(MX2307)DataLoggerManual
1‐508‐759‐9500(U.S.andInternational)5www.onsetcomp.com
1‐800‐LOGGERS(U.S.only) 
loggerispressedtowakeitup,therebypreservingasmuch
batterypoweraspossible.
12. SelectSoilType:
Mineral–forcommonsoils,withECvaluesupto8
dS/m.
Soilless–forpottingsoils,perlite,andpeatmosswith
ECvaluesupto8dS/m.
ApparentDielectricPermittivity–rawmeasurements
thatcanbeusedinpublishedequationssuchasthe
Toppequationtoderivesoilmoisturedata.
13. EnableordisablePercentofFieldCapacity–Toseesoil
moistureasthepercentoffieldcapacity,enablethisand
enterthefieldcapacityforthesoilatthesiteinVolumetric
WaterContentonascaleof0.01to1.00.Notethatthe
PercentofFieldCapacityvaluesreportedwillbelimitedto
therangeof0%to200%.IfyouselectedApparentDielectric
Permittivityasyoursoiltype,theoptionforPercentofField
Capacityisdisabled.
14. SelectwhethertouploaddataviatheHOBOconnectappor
theMXGateway.UsingtheMXGatewayrequiresa
HOBOlinkaccount.
15. Enable/Disablethesensorsthatwillbelogged(MX2307
model)andsetupanyalarmstotripwhenasensorreading
risesaboveorfallsbelowaspecifiedvalue.SeeSettingup
Alarmsfordetailsonenablingsensoralarms.Notethatfor
theMX2307,temperatureisshownaschannel3.Thisis
becausechannel2isreservedforApparentDielectric
Permittivity,ifthatisselected.
16. Taptosavetheconfigurationsettings,andstart
loggingbasedonthesettingsyouselected.Pressthestart
buttonontheloggerifitwassetuptostartloggingwitha
buttonpush.SeeDeployingandMountingtheLoggerfor
detailsonmountingandseeReadingOuttheLoggerfor
detailsondownloading.
SettingupAlarms
Youcansetupalarmsfortheloggersothatifasensorreading
risesaboveorfallsbelowaspecifiedvalue,theloggeralarm
LEDwillblinkandanalarmiconwillappearintheapp.Thiscan
alertyoutoproblemssoyoucantakecorrectiveaction.
Tosetanalarm:
1. TapDevices.Pressthebuttonontheloggertowakeitup(if
necessary).
2. Taptheloggerintheapptoconnecttoitandtap.
3. Tapasensor(taptheEnableLoggingtoggleifnecessary).
4. SelectHighifyouwantanalarmtotripwhenthesensor
readingrisesabovethehighalarmvalue.Dragtheslideror
typeavaluetosetthehighalarmvalue.
5. SelectLowifyouwantanalarmtotripwhenthesensor
readingfallsbelowthelowalarmvalue.Dragtheslideror
typeavaluetosetthelowalarmvalue.
6. FortheDuration,selecthowmuchtimeshouldelapse
beforethealarmtrips,andselectoneofthefollowing:
Cumulative.Thealarmwilltriponcethesensorreadingis
outoftheacceptablerangefortheselecteddurationany
timeduringlogging.Forexample,ifthelowalarmisset
to0.05
m³/m³ forasoilmoisturealarmandtheduration
issetto30minutes,thealarmwilltriponcethesensor
readingshavebeenbelow0.05
m³/m foratotalof30
minutessincetheloggerwasstarted.
Consecutive.Thealarmwilltriponcethesensorreading
isoutoftheacceptablerangecontinuouslyforthe
selectedduration.Forexample,ifthelowalarmissetto
0.05
m³/m³ forasoilmoisturealarmandthedurationis
setto30minutes,thealarmwillonlytripifallsensor
readingshavebeenbelow0.05 m³/m foracontinuous30‐
minuteperiod.
7. TapSave.ForMX2307models,repeatsteps3–7forthe
othersensorifdesired.
8. Intheconfigurationsettings,selectoneofthefollowing
optionstodeterminehowthealarmindicationsarecleared:
LoggerReconfigured.Thealarmiconindicationwill
displayuntilthenexttimetheloggerisreconfigured.
SensorinLimits.Thealarmiconindicationwilldisplay
untilthesensorreadingreturnstothenormalrange
betweenanyconfiguredhighandlowalarmlimits.
Whenanalarmtrips,theloggeralarmLEDblinksevery4
seconds(unlessShowLEDisdisabled),analarmiconappearsin
theapp,andanAlarmTrippedeventislogged.Thealarmstate
willclearwhenthereadingsreturntonormalifSensorinLimits
wasselectedinstep8.Otherwise,thealarmstatewillremainin
placeuntiltheloggerisreconfigured.
Notes:
Alarmlimitsarecheckedateverylogginginterval.For
example,iftheloggingintervalissetto5minutes,the
loggerwillcheckthesensorreadingsagainstthe
configuredhighandlowalarmsettingevery5minutes.
Theactualvaluesforthehighandlowalarmlimitsareset
totheclosestvaluesupportedbythelogger.Inaddition,
alarmscantriporclearwhenthesensorreadingiswithin
theresolutionspecifications.
Whenreadingoutthelogger,alarmeventscanbe
displayedontheplotorinthedatafile.SeeLogger
Events.
BurstLogging
Burstloggingisaloggingmodethatallowsyoutosetupmore
frequentloggingwhenaspecifiedconditionismet.For
example,anMX2307loggerisrecordingdataata5‐minute
loggingintervalandburstloggingisconfiguredtologevery30
secondswhenthetemperaturerisesabove85°F(thehighlimit)
orfallsbelow32°F(thelowlimit).Thismeanstheloggerwill
recorddataevery5minutesaslongasthetemperature
remainsbetween85°Fand32°F.Oncethetemperaturerises
above85°F,theloggerwillswitchtothefasterloggingrateand
recorddataevery30secondsuntilthetemperaturefallsback
to85°F.Atthattime,loggingresumesevery5minutesatthe
normallogginginterval.Similarly,ifthetemperaturefallsbelow
32°F,theloggerwouldswitchtoburstloggingmodeagainand
recorddataevery30seconds.Oncethetemperaturerisesback
to32°F,theloggerwillreturntonormalmode,loggingevery5
minutes.Note:Sensoralarms,statistics,andtheStopLogging
option“WrapWhenFull”arenotavailableinburstlogging
mode.

HOBOMXSoilMoisture(MX2306)andMXSoilMoistureandTemperature(MX2307)DataLoggerManual
1‐508‐759‐9500(U.S.andInternational)6www.onsetcomp.com
1‐800‐LOGGERS(U.S.only) 
Tosetupburstlogging:
1. TapDevices.Pressthebuttonontheloggertowakeitup(if
necessary).
2. Taptheloggerintheapptoconnecttoitandtap.
3. TapLoggingModeandthentapBurstLogging.
4. SelectLowand/orHighandeithertypeordragthesliderto
setthelowand/orhighvalues.
5. Repeatstep4fortheothersensorifdesired.
6. Settheburstlogginginterval,whichmustbefasterthanthe
logginginterval.Keepinmindthatthefastertheburst
loggingrate,thegreatertheimpactonbatterylifeandthe
shortertheloggingduration.Becausemeasurementsare
beingtakenattheburstloggingintervalthroughoutthe
deployment,thebatteryusageissimilartowhatitwouldbe
ifyouhadselectedthisrateforthenormallogginginterval.
7. TapSave.
Notes:
Thehighandlowburstlimitsarecheckedattheburst
loggingintervalratewhethertheloggerisinnormalor
burstcondition.Forexample,iftheloggingintervalisset
to1hourandtheburstloggingintervalissetto10
minutes,theloggerwillalwayscheckforburstlimits
every10minutes.
Ifhighand/orlowlimitshavebeenconfiguredformore
thanonesensor,burstloggingwillbeginwhenanyhigh
orlowconditiongoesoutofrange.Burstloggingwillnot
enduntilallconditionsonallsensorsarebackwithin
normalrange.
Theactualvaluesfortheburstlogginglimitsaresetto
theclosestvaluesupportedbythelogger.
Burstloggingcanbeginorendwhenthesensorreadingis
withintheresolutionspecifications.Thismeansthevalue
thattriggersburstloggingmaydifferslightlythanthe
valueentered.
Oncethehighorlowconditionclears,thelogging
intervaltimewillbecalculatedusingthelastrecorded
datapointinburstloggingmode,notthelastdatapoint
recordedatthenormalloggingrate.Forexample,the
loggerhasa10‐minuteloggingintervalandloggedadata
pointat9:05.Then,thehighlimitwassurpassedand
burstloggingbeganat9:06.Burstloggingthencontinued
until9:12whenthesensorreadingfellbackbelowthe
highlimit.Nowbackinnormalmode,thenextlogging
intervalwillbe10minutesfromthelastburstlogging
point,or9:22inthiscase.Ifburstlogginghadnot
occurred,thenextdatapointwouldhavebeenat9:15.
ANewIntervaleventiscreatedeachtimethelogger
entersorexitsburstloggingmode.SeeLoggerEventsfor
detailsonplottingandviewingtheevent.Inaddition,if
theloggerisstoppedwithabuttonpushwhileinburst
loggingmode,aNewIntervaleventisautomatically
loggedandtheburstconditioniscleared,evenifthe
actualhighorlowconditionhasnotcleared.
StatisticsLogging
Duringfixedlogging,theloggerrecordsdataforenabled
sensorsand/orselectedstatisticsatthelogginginterval
selected.Statisticsarecalculatedatasamplingrateyouspecify
withtheresultsforthesamplingperiodrecordedateach
logginginterval.Thefollowingstatisticscanbeloggedforeach
sensor:
Themaximum,orhighest,sampledvalue
Theminimum,orlowest,sampledvalue
Anaverageofallsampledvalues
Thestandarddeviationfromtheaverageforallsampled
values.
Forexample,anMX2307loggerisconfiguredwithboththesoil
moistureandtemperaturesensorsenabled,andthelogging
intervalissetto5minutes.Theloggingmodeissettofixed
loggingwithNormalandallfourstatisticsenabledandwitha
statisticssamplingintervalof30seconds.Onceloggingbegins,
theloggerwillmeasureandrecordtheactualsoilmoistureand
temperaturesensorvaluesevery5minutes.Inaddition,the
loggerwilltakeasoilmoistureandtemperaturesampleevery
30secondsandtemporarilystoretheminmemory.Thelogger
willthencalculatethemaximum,minimum,average,and
standarddeviationusingthesamplesgatheredoverthe
previous5‐minuteperiodandlogtheresultingvalues.When
readingoutthelogger,thiswouldresultin10dataseries:two
sensorseries(withsoilmoistureandtemperatureloggedevery
5minutes)pluseightmaximum,minimum,average,and
standarddeviationseries(fourforsoilmoistureandfourfor
temperaturewithvaluescalculatedandloggedevery5minutes
basedonthe30‐secondsampling).
Tologstatistics:
1. TapDevices.Pressthebuttonontheloggertowakeitup(if
necessary).
2. Taptheloggerintheapptoconnecttoitandtap.
3. TapLoggingModeandthenselectFixedLogging.
4. SelectNormaltorecordthecurrentreadingforeach
enabledsensorattheloggingintervalshownatthetopof
thescreen.Donotselectthisifyouonlywanttolog
statistics.
5. Selectthestatisticsyouwanttheloggertorecordateach
logginginterval:Maximum,Minimum,Average,and
StandardDeviation(averageisautomaticallyenabledwhen
selectingStandardDeviation).Statisticswillbeloggedforall
enabledsensors.Inaddition,themorestatisticsyourecord,
theshortertheloggerdurationandthemorememoryis
required.
6. TapStatisticsSamplingIntervalandselecttheratetouse
forcalculatingstatistics.Theratemustbelessthan,anda
factorof,thelogginginterval.Forexample,ifthelogging
intervalis1minuteand5secondswasselectedforthe
samplingrate,theloggerwilltake12samplereadings
betweeneachlogginginterval(onesampleevery5seconds
foraminute)andusethe12samplestorecordtheresulting
statisticsateach1‐minutelogginginterval.Notethatthe
fasterthesamplingrate,thegreatertheimpactonbattery
life.Becausemeasurementsarebeingtakenatthestatistics
samplingintervalthroughoutthedeployment,thebattery
usageissimilartowhatitwouldbeifyouhadselectedthis
rateforthenormallogginginterval.
7. TapSave.

HOBOMXSoilMoisture(MX2306)andMXSoilMoistureandTemperature(MX2307)DataLoggerManual
1‐508‐759‐9500(U.S.andInternational)7www.onsetcomp.com
1‐800‐LOGGERS(U.S.only) 
SettingaPassword
Youcancreateanencryptedpasswordfortheloggerthatwill
berequiredifanotherdeviceattemptstoconnecttoit.Thisis
recommendedtoensurethatadeployedloggerisnot
mistakenlystoppedorpurposelyalteredbyothers.This
passwordusesaproprietaryencryptionalgorithmthatchanges
witheveryconnection.
Tosetapassword:
1. TapDevices.Pressthebuttonontheloggertowakeitup(if
necessary).Taptheloggerintheapptoconnecttoit.
2. Tap(ifapplicable)andthen.
3. TypeapasswordandthentapSet.
Onlythedeviceusedtosetthepasswordcanthenconnectto
theloggerwithoutenteringapassword;allotherdeviceswill
berequiredtoenterthepassword.Forexample,ifyousetthe
passwordfortheloggerwithyourtabletandthentryto
connecttotheloggerlaterwithyourphone,youwillbe
requiredtoenterthepasswordonthephonebutnotwithyour
tablet.Similarly,ifothersattempttoconnecttotheloggerwith
differentdevices,theywouldalsoberequiredtoenterthe
password.Toresetapassword,pressthebuttononthelogger
for10secondsorconnecttotheloggerandtap(if
applicable),then,andtapReset.
ReadingOuttheLogger
Tooffloaddatafromthelogger:
1. TapDevices.Pressthebuttonontheloggertowakeitup(if
necessary).
2. Taptheloggerintheapptoconnecttoitandtap.The
loggerwillreadoutthedatatothephone,tablet,or
computer.
3. Oncethereadoutiscomplete,tapHOBOFilesandselect
thefiletoviewit.Tap(ifapplicable)andtapto
exportthedata.
DatacanalsobeuploadedautomaticallytoHOBOlink,Onset’s
web‐basedsoftware,viatheapportheMXgateway.For
details,seetheappuser’sguideandseetheHOBOlinkhelpfor
detailsonworkingwithdatainHOBOlink.
LoggerEvents
Theloggerrecordsthefollowinginternaleventstotracklogger
operationandstatus.Youcanvieweventsinexportedfilesor
ploteventsintheapp.
Toplotevents,tapHOBOFilesandselectafiletoopen.
Tap(ifapplicable)andthentap.Selecttheeventsyou
wanttoplotandtapOK.
InternalEventNameDefinition
HostConnectedTheloggerwasconnectedtothemobile
device.
StartedTheloggerstartedlogging.
InternalEventNameDefinition
StoppedTheloggerstoppedlogging.
Alarm
Tripped/Cleared
Analarmhasoccurredbecausethe
readingwasoutsidethealarmlimitsor
backwithinrange.Note:Althoughthe
readingmayhavereturnedtoanormal
rangeduringlogging,analarmcleared
eventwillnotbeloggediftheloggerwas
setuptomaintainalarmsuntil
reconfigured.
NewIntervalTheloggerhasswitchedtologgingatthe
burstloggingrateorbacktothenormal
rate.
SafeShutdownThebatteryleveldroppedbelowasafe
operatingvoltageandthelogger
performedasafeshutdown.
InstallingtheSoilMoistureSensor
Therearetwoinstallationmethodsforinstallingthesoil
moisturesensor:boreholeortrench.
BoreholeInstallationMethod
Thismethodallowsforaprofileofsoilmoisturesensorstobe
installedatdifferentdepthswithinasingleaugeredborehole,
therebyminimizingsoildisturbanceatthemeasurementsite.A
10‐cm(4‐inch)boreholeisaugeredverticallyatthe
measurementlocation.Youcanthencarefullyinsertandplace
thesensorbyhandorbuyorrenttheBoreholeInstallationTool
fromMeter(recommendedfordepthsgreaterthan50cm(19.7
inches).EmailMeterat[email protected](NorthAmerica)
or[email protected](Europe)fordetailsonbuying
orrentingthetool.

IfinstallingthesensorwithouttheBoreholeInstallationTool,
lookdowntheholewithaflashlight,reachinwiththesensor
andpushitintotothesideoftheundisturbedsoil.Lookdown
theholeagainandmakesureitisfirmlyseated.Youcanalso
considerattachingthesensortoPVCpipingorsimilarmaterial
toaidinplacingthesensor.YoucanthenusethePVCasalever
toassistwithpushingthesensorintotheundisturbedsoil.

HOBOMXSoilMoisture(MX2306)andMXSoilMoistureandTemperature(MX2307)DataLoggerManual
1‐508‐759‐9500(U.S.andInternational)8www.onsetcomp.com
1‐800‐LOGGERS(U.S.only) 
TrenchInstallationMethod
Thismethodisbestforshallowinstallationsatlessthan40cm
(15.7inches).Thisrequiresdiggingatrenchwithashovel,
excavator,orothertooltothedepthofthedeepestinstalled
sensor(ifinstallingmorethanoneinthemeasurement
location).Fordeepinstallations,thismayrequirealargetrench.
Thesensoristheninstalledcarefullybyhandintothe
undisturbedsoilofthetrenchsidewall.Thetrenchiscarefully
backfilledtopreservethebulkdensityofthesoilandavoid
dislodgingtheinstalledsensorbyaccidentallysnaggingthe
ferritecore.

SensorInstallationGuidelines
Beforeinstallingthesensor,followtheseguidelines:
TestthesensorfunctionalityandaccuracyusingtheTEROS
verificationclip.Withtheverificationclipattached,the
readingsshouldbeintherangeof0.35to0.42m
3
/m
3
.
RefertotheTEROSverificationclipdocumentationfor
moreinformation.Ifyoudonothaveaverificationclip,
youcanperformaroughcheckofsensorfunctionalityin
airandwater.Thesensorwillproducereadingsof~0.64
m
3
/m
3
inwater(sensorfullysubmergedinwaterto1cm
upcable)andslightlynegativeinair.UseHOBOconnectto
exportorviewthedataforyourtest.
Whencreatingtheholetoinstallthesensor,avoid
interferingobjects.Installationnearlargemetalobjects
canaffectthesensorfunctionanddistortreadings.Large
objectslikerootsorrockscouldpotentiallybendthe
needles.
Thesensormaybepositionedinanydirection.However,
thereislessrestrictiontowaterflowwhenthesensor
bodyisplacedinaverticalpositionasshownbelow.A
verticalpositionwillalsointegratemoresoildepthinto
thesoilmoisturemeasurement.Installingthesensorwith
thesensorbodyinahorizontalpositionwillprovide
measurementsatamorediscreetdepth.

Avoidanymetallocatedbetweenthesensorandthe
ferritecorebecauseitcaninterferewithVWC
measurements.
Wheninstallingsensorsinrockysoils,usecaretoavoid
bendingsensorneedles.
Minimizeairgapsaroundthesensor.Airgapsaroundthe
sensorneedleswillresultinlowreadingsofsoilmoisture.
Useconduittoprotectthecableagainstdamagefrom
animals,lawnmowers,exposuretochemicals,etc.
Secureanyloosecableswithcableties.
SensorInstallationInstructions
1. Augerordigaholetothedesiredsensordepth.
2. Carefullyinsertthesensorintheholeandpushthesensor
sothattheneedlesareinsertedintotheundisturbedsideof
thesoil.Checkthatthesensorisfirmlyseated.
3. Ifusingthetemperaturesensorforsoiltemperature,insert
thatintothesideofthehole,atleast2cm(1inch)fromthe
soilmoisturesensorandferritecore.
4. Securethecable(s)andinstallconduitbeforebackfillingthe
hole.
5. Carefullyreturnthesoiltothehole,packingitbacktoits
nativebulkdensity.Donothittheferritecoreasthiscould
pullthesensorfromthesoil.
6. IfusingtheMX2307loggerforairtemperature,asolar
radiationshieldisrequiredifthetemperaturesensorwillbe
insunlightatanytime.(SeeAccessories)
DeployingandMountingtheLogger
Followtheseguidelineswhendeployingthelogger:
Mounttheloggersothesensorcableisnotbeingpulled.
Leaveabout5cm(2inches)ofdriploopinthecable
whereitcomesoutoftheloggertopreventwaterfrom
enteringtheloggerhousing.

Usetheincludedlargescrewsorcabletiestomount
theloggerviathemountingholes.Usethescrewsto
attachtheloggertoawallorflatsurface.Usethe
cabletiestoaffixtheloggertoaPVCpipeormast.
ProtectingtheLogger
Note:Staticelectricitymaycausetheloggertostoplogging.
Theloggerhasbeentestedto8KV,butavoidelectrostatic
dischargebygroundingyourselftoprotectthelogger.Formore
information,searchfor“staticdischarge”ononsetcomp.com.
DripLoop



©2015–2022OnsetComputerCorporation.Allrightsreserved.Onset,HOBO,HOBOconnect,andHOBOlinkareregisteredtrademarksof
OnsetComputerCorporation.AppStore,iPhone,iPad,andiPadOSareservicemarksorregisteredtrademarksofAppleInc.Androidand
GooglePlayaretrademarksofGoogleLLC.WindowsisaregisteredtrademarkofMicrosoftCorporation.BluetoothandBluetoothSmart
areregisteredtrademarksofBluetoothSIG,Inc.Allothertrademarksarethepropertyoftheirrespectivecompanies.
Patent#:8,860,569 
26456‐A
1‐508‐759‐9500(U.S.andInternational)
1‐800‐LOGGERS(564‐4377)(U.S.only)
www.onsetcomp.com/support/contact
Maintenance
Tocleanthesoilmoisturesensorandneedles,useamild
detergent,suchasliquiddishsoap,andanonabrasivesponge
orcloth.Avoiddetergentsthatcontainlotionsormoisturizers.
Rinsethesensorandneedlesthoroughlywithtapordeionized
(DI)water.The logger is designed for outdoor use, but should be
inspected periodically. Wipe off any dust or grime with a damp
cloth. 
Troubleshooting
Ifthesoilmoisturesensorreadingsaretooloworslightly
negative,checkforairgapsaroundthesensorneedles.These
couldbeproducedbelowthesurfaceofthesubstratewhenthe
needlecontactsalargepieceofmaterialandpushesitoutof
theway,orifthesensorisnotinsertedperfectlylinearly.
Ifthesensorreadingsaretoohigh,makesurethemediawas
notpackedexcessivelyorinsufficientlyduringsensor
installation.Higherdensitycancausethesensorreadingstobe
elevated.
BatteryInformation 
Theloggerrequiresoneuser‐replaceable2/3AA3.6Vlithium
battery(HRB‐2/3AA).Batterylifeis2years,typicalwitha
loggingintervalof1minute,butmaybeextendedto5years
whentheloggerisconfiguredwithBluetoothAlwaysOn
disabled.Expectedbatterylifevariesbasedontheambient
temperaturewheretheloggerisdeployed,theloggingor
samplinginterval,frequencyofoffloadingandconnectingto
themobiledevice,numberofchannelsthatareactive,anduse
ofburstmodeorstatisticslogging.Deploymentsinextremely
coldorhottemperaturesorloggingintervalfasterthan1
minutecanimpactbatterylife.Estimatesarenotguaranteed
duetouncertaintiesininitialbatteryconditionsandoperating
environment.








BatteryReplacement
1. UseaPhillips‐headscrewdrivertounscrewthefour
screwsfromthebackofthelogger.
2. Carefullyseparatethetopandbottomofthelogger
enclosure.
3. Removetheoldbatteryandinsertthenewbattery
observingpolarity.Itisrecommendedthatyou
replacethedesiccant(DESICCANT2)whenreplacing
thebattery.
4. Makesuretherubbersealiscleanandfreeofany
debrisandthencarefullyreassemblethelogger
enclosureandscrewinthefourscrews.
WARNING:Donotcutopen,incinerate,heatabove85°C(185°F),
orrechargethelithiumbattery.Thebatterymayexplodeiftheloggeris
exposedtoextremeheatorconditionsthatcoulddamageordestroy
thebatterycase.Donotdisposeoftheloggerorbatteryinfire.Donot
exposethecontentsofthebatterytowater.Disposeofthebattery
accordingtolocalregulationsforlithiumbatteries.

FederalCommunicationCommissionInterferenceStatement
ThisequipmenthasbeentestedandfoundtocomplywiththelimitsforaClassBdigitaldevice,pursuanttoPart15oftheFCCRules.Theselimitsaredesignedtoprovide
reasonableprotectionagainstharmfulinterferenceinaresidentialinstallation.Thisequipmentgeneratesusesandcanradiateradiofrequencyenergyand,ifnotinstalledand
usedinaccordancewiththeinstructions,maycauseharmfulinterferencetoradiocommunications.However,thereisnoguaranteethatinterferencewillnotoccurina
particularinstallation.Ifthisequipmentdoescauseharmfulinterferencetoradioortelevisionreception,whichcanbedeterminedbyturningtheequipmentoffandon,theuser
isencouragedtotrytocorrecttheinterferencebyoneofthefollowingmeasures:
Reorientorrelocatethereceivingantenna
Increasetheseparationbetweentheequipmentandreceiver
Connecttheequipmentintoanoutletonacircuitdifferentfromthattowhichthereceiverisconnected
Consultthedealeroranexperiencedradio/TVtechnicianforhelp
ThisdevicecomplieswithPart15oftheFCCRules.Operationissubjecttothefollowingtwoconditions:(1)Thisdevicemaynotcauseharmfulinterference,and(2)thisdevice
mustacceptanyinterferencereceived,includinginterferencethatmaycauseundesiredoperation.
FCCCaution:Anychangesormodificationsnotexpresslyapprovedbythepartyresponsibleforcompliancecouldvoidtheuser'sauthoritytooperatethisequipment.
IndustryCanadaStatements
ThisdevicecomplieswithIndustryCanadalicense‐exemptRSSstandard(s).Operationissubjecttothefollowingtwoconditions:(1)thisdevicemaynotcauseinterference,and
(2)thisdevicemustacceptanyinterference,includinginterferencethatmaycauseundesiredoperationofthedevice.
Avisdeconformitépourl’IndustrieCanada
LeprésentappareilestconformeauxCNRd'IndustrieCanadaapplicablesauxappareilsradioexemptsdelicence.L'exploitationestautoriséeauxdeuxconditionssuivantes:(1)
l'appareilnedoitpasproduiredebrouillage,et(2)l'appareildoitacceptertoutbrouillageradioélectriquesubi,mêmesilebrouillageestsusceptibled'encompromettrele
fonctionnement.TocomplywithFCCandIndustryCanadaRFradiationexposurelimitsforgeneralpopulation,theloggermustbeinstalledtoprovideaseparationdistanceofat
least20cmfromallpersonsandmustnotbeco‐locatedoroperatinginconjunctionwithanyotherantennaortransmitter.
Unscrewthesefour
screwstoreplace
thebattery