Sutron Accubar SDI-12 Manual

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SDI‐TB
SDI‐12TippingBucketInterface
withSmartCompensation
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Operations&Maintenance
Manual
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PartNo.8800‐1205
Revision1.1
25May2018
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SutronCorporationSDI‐TBUsersManual   Rev.1.1 5/24/2018 pg.2
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TABLEOFCONTENTS
1.Introduction.....................................................................................................................................3
2.QuickStart.......................................................................................................................................3
2.1Unpacking...........................................................................................................................3
2.2Operation...........................................................................................................................4
2.3Connections........................................................................................................................7
2.4SensorConfiguration..........................................................................................................7
3.CommandReference........................................................................................................................8
3.1StandardSDI‐12commands...............................................................................................8
3.2ExtendedSDI‐12commands............................................................................................11
AppendixA:Specifications&OrderingInformation......................................................................15
AppendixB:CustomerServicePolicy............................................................................................16
AppendixC:CommercialWarranty...............................................................................................18
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SutronCorporationSDI‐TBUsersManual   Rev.1.1 5/24/2018 pg.3
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1. Introduction
TheSDI‐TBisanultralowpower,compactandruggedSDI‐12raingaugesensor.Itcanbeconfiguredtowork
withmosttippingbucketsizesandconfigurationsandsupportsacorrectionpolynomialforhighrainfallrate
compensation.TheSDI‐TBalsohasnumerousbuiltinfeatureslikeprogrammabledailyrainfallresettime,
programmableyearlyreset.TheSDI‐TBsensorhasabackuppowersourcethatpermitsun‐interrupted
operationforupto10hoursincaseSDI‐12powerislost.
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2. QuickStart
2.1 Unpacking
RemoveSDI‐TBsensorfromtheshippingcontainerandvisuallyinspecttheunitforsignsofdamage
duringshipment.Reportanysuchdamagetothefactoryimmediatelytoensureapromptresponseand
resolution.Retainoneshippingcontainerintheeventafactoryreturnisnecessary.
Pleasenotethatifareturnisrequired,areturnmaterialauthorization(RMA)numberisrequired.Toget
thisRMAnumber,calltheSutronCustomerServiceDepartmentat703‐406‐2800.
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SutronCorporationSDI‐TBUsersManual   Rev.1.1 5/24/2018 pg.4
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2.2 Operation
IMPORTANT:OnpoweringuptheSDI‐TBforthefirsttime,theSDI‐TBrequiresabout2minutesforthe
internalcapacitortochargeupandthesupplyvoltagetogetuptotheminimumvoltagethreshold
requiredforthemoduletobeoperational.Thecapacitortypicallytakesabout10hourstodischarge
oncecompletelycharged
Readinganyoftheseregisterswillinitiateanewmeasurementandthemeasuredvaluewillbereturned.
TheSDI‐TBprovidesastandard3‐wireSDI‐12bustointerfacewithanySDI‐12v1.3compliantloggerand
a2‐wireinterfaceforconnectiontostandardTippingbuckets.
MostTippingbucketsconsistofabucketattachedtoasimpleswitch.Theswitchmakesabriefcontact
betweenthetwowiresasthebuckettips.TheSDI‐TBincrementsthecumulativetotalanddailyrainfall
andrawtipcountforeachtipitrecords.TheSDI‐TBcanbeconfiguredtorecordatiponafallingedgeor
risingedge.Apull‐uporpull‐downresistorisautomaticallyactivedependingonwhetherafallingedge
orrisingedgerespectivelyhasbeenconfigured.
Auserprogrammabledebouncingdurationcanbeconfiguredtofilteroutnoiseduringthevoltage
transitionsastheswitchmakes/breakscontact.
TheSDI‐TBusesaconfigurable‘Bucketsize’orathirdordercompensationpolynomialtoconverttips
intorainfall.Thebucketsizeindicatestheamountofrainfallthatcorrespondstoasingletipofthe
bucket.Bydefault(ifnocompensationhasbeenprogrammed)theSDI‐TBincrementsthetotal
accumulationaftereachvalidtip.Thenewaccumulationsiscalculatedusingtheformula
    
Sincethebuckettakesafiniteamountoftimetotipoverandstartfillingagain,somerainwillbelost
beforethebucketisinpositiontocollectrainagain.Thisamountofrainfalllostwillbecomemore
significantastherainfallrateincreases.Tocompensateforsuchheavyrainfallrates,theSDI‐TBsupports
athirdorderpolynomialwithuserconfigurablecoefficients.Thepolynomialisusedtocomputethe
rainfallforeachtipbasedonhowfrequentlythebuckettips.Thepolynomialisoftheform
/  
 
Thecoefficientscanbeobtainedbyplottingtherainfallininches/houronthex‐axisandthe
compensatedrain(inches/tip)ontheY‐axisandfittingtheresultantcurvetoathirdorderpolynomial.
Thefollowingplotshowsthecurvefora0.01inchbucket.

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SutronCorporationSDI‐TBUsersManual   Rev.1.1 5/24/2018 pg.5
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TheSDI‐TBmeasuresthetimebetweenthecurrenttipandtheprevioustipandusesthebucketsizeto
computetheequivalentrainfallininches/hour.Thepolynomialisthenusedtoconverttheresultant
rainfallininches/hourtorainfallpertip.Ifthecoefficientshavenotbeenconfigured,thebucketsizeis
used.
TheSDI‐TBhasaninternalRealTimeClock(RTC)thatisusedtokeeptimeandcanbeprogrammedto
performdailyandannualrainfallresets.
TheSDI‐TBhasabuiltinrechargeablebackuppowersourcethatisusedtopowerthemoduleforupto
10hoursofuninterruptedoperationincaseSDI‐12powerislost.Thecurrentdrawwillbehigherduring
thechargingphaseandreduceovertime,tillthebackuppowersourceiscompletelycharged.
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0.009
0.0095
0.01
0.0105
0.011
0.0115
0.012
0.0125
0.013
0.0135
0 5 10 15 20 25 30
Inches/tip
Rain(inches/hour)

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SutronCorporationSDI‐TBUsersManual   Rev.1.1 5/24/2018 pg.6
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Fig:ChargingcurrentvsTime
TheinternalRTCandTippingbucketinterfacesarefullyfunctionalwhilerunningoffthebackuppower
source.However,theSDI‐12interfaceisdisabledwhilerunningoffbackuppower.TheSDI‐12interface
functionalityisautomaticallyrestoredwhenSDI‐12powerisrestored.
TheSDI‐TBisfullycompliantwiththeSDIprotocolv1.3The‘D0’commandissuedafteran‘M’command
returnsvariousaccumulationsandcountervalues.
Foreg
Command=aM!
Response=a0005
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Command=aD0
Response=a+<acc_last>+<raw_tip_year>+<acc_year>+<acc_daily>+<acc_yest>
<acc_last>=totalaccumulationssincethelastMcommandwasissued.EverytimeanM
commandisissued,thisparameterwillbereset.
<raw_tip_year>=TheSDI‐TBcanbeprogrammedtoresetitsannualcounters/accumulationat
thestartofarainyear.Thisparameterreturnsthetotalrawtipcountsforthecurrentrain‐year.
<acc_year>=Thisparameterreturnsthetotalrainfallforthecurrentrain‐year.
<acc_daily>=TheSDI‐TBcanbeprogrammedtoresetthedailyrainfallvalueonceeveryday.
Thisparameterreturnsthetotalrainfalltoday.
<acc_yest>=Thisparameterreturnsthetotalaccumulationyesterday.Eachtimethedaily
accumulationisresetbythedailytimer,thetotalaccumulationtodayissavedasyesterday’s
accumulation.
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SutronCorporationSDI‐TBUsersManual   Rev.1.1 5/24/2018 pg.7
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2.3 Connections
TheSDI‐TBsensorisverysimpletoconnectandgetworking.Theunithasa5positionpushheaderfor
interfacingwithanSDIloggerandastandard2‐wireTippingbucket.
PinLabelDescription
TB‐INConnecttothereedswitchterminalofthetippingbucket.
GNDGroundconnectionfortheTippingbucket
SDI‐12Data BidirectionalSDIdatabus
GNDSDI‐12interfaceGroundconnection
Power(4v‐20vSDI‐12powerfromthelogger/SDI‐12master
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2.4 SensorConfiguration
TheSDI‐TBsensorsareconfiguredatthefactorytothedefaultSDIaddress0.IfotherSDI12sensorsare
presentontheSDI12bus,theaddressmustbechangedusingthestandard‘addresschange’command.
RefertotheSDI‐12commandtablebelowforinstructionsonhowtochangetheaddressifneeded.
TheSDI‐TBhasadefaultdebouncingof15ms.Ifthebuckethasaswitchclosetimeotherthan15ms,the
appropriatedebouncedurationcanbesetusingtheXDBNCcommand.
IfthetippingBucketbeingusedhasacapacityotherthanthedefaultsize(0.01”),thebucketsizemust
besetusingtheXBKTSZcommand.
Ifthetippingbucketbeinguseddoesnothaveasiphonortheuserwishestocompensateforheavy
rainfallrates,theXCOMPcommandmustbeusedtosetthepolynomialcoefficients.
TheSDI‐TBsensorisSDI‐12compliantandwillrespondtoallSDI‐12commandsaccordingtoversion1.3
ofthestandard.TousetheSDI‐12commandsyoumusthaveadataloggerorinterfacethatsupports
theSDI‐12standard.MoredetailsontheSDI‐12interfacecanbefoundathttp://www.sdi‐12.org.
ThegeneralformofanSDI‐12commandis:
aC!<CR><LF>
Whereaisthesensoraddress0‐9,A‐Z,a‐z,*,?.(Addresses*and?willaddressanysensor,regardlessof
itsaddress.)
Cisthecommandand!isthelastcharacterofthecommand.

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SutronCorporationSDI‐TBUsersManual   Rev.1.1 5/24/2018 pg.8
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ItisexpectedthattheuserisfamiliarwiththeSDI‐12protocolandthissectioniswrittenaccordingly.
3. CommandReference
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3.1 StandardSDI‐12commands
CommandNameCommandResponseNotes
?QuerySDI
Address?!
A
where
a=address
OnlyoneSDI‐12
deviceshouldbe
connectedtothebus
sinceallwillrespond.
Acknowledge
Activea!A
ISend
IdentificationaI!
Foramastertheexpected
responseis
a13SUTRONSDI‐TBsssssssvx.xx
a
13
SUTRON=manufacturer
SDI‐TB=modelnumber
sssssss=Serialnumber
x.xx=softwarerevisionnumber
Identificationstring
forSDI‐TBsensor.
AChange
Address
aAb!

Example:
0A5!
b
Indicatingnewaddress
example
5




SutronCorporationSDI‐TBUsersManual   Rev.1.1 5/24/2018 pg.9



CommandNameCommandResponseNotes
M
MC
C
CC
Get
accumulation
andrawtip
values
aM!
(orMC,C,CC)
Ex:
8M!

aD0!
Ex:
0D0!


a0005
5valuesavailablein0seconds.
UseD0toretrievedata.
a+<acc_last>+<rawtip_years>
+<acc_year>+<acc_daily>+<acc_yes
t>
where:
a=Sensoraddress
<acc_last>=Rainfallsincelast
measurement
<raw_tip_years>=Totalrawtips
thisyear
<acc_year>=Totalaccumulation
thisyear
<acc_daily>=Totalaccumulation
today
<acc_yest>=Totalaccumulation
Yesterday
Ex:
0+0.01+12+0.12+0.03+0.02
Returnsthecurrent
accumulationvalues
andresetsthe
accumulatedrainfall
sincelast
measurement.
M1
MC1
C1
CC1
Getrainfallin
last‘x’
minutes.
aM1!
(orMC1,C1,
CC1)
Ex:
0M1!

aD0!
Ex:
0D0!

a0002
2valuesavailablein0seconds.Use
D0toretrievedata.

a+<acc_x_minutes><x>

where:
a=address
<acc_x_minutes>=rainfall
<x>=durationforwhichrainfallis
reported

Ex:
0+0.03+15
Returnstheainfallin
thelast‘x’minutes,
wherexcanbeset
usingtheextended
command‘XIDUR’
describedthe
‘ExtendedSDI‐12
commands’table.




SutronCorporationSDI‐TBUsersManual   Rev.1.1 5/24/2018 pg.10







SutronCorporationSDI‐TBUsersManual   Rev.1.1 5/24/2018 pg.11



3.2 ExtendedSDI‐12commands
CommandNameCommandResponseNotes
XDT
Read/Write
current
system
time
aXDT!
or
aXDT+yyyy/mm/dd
hh:mm:ss!

Ex:
0XDT+!
or
0XDT+2015/04/24
17:45:31
SetstimetoApril24,2015
5:45.31pm.
a+yyyy/mm/dd
hh:mm:ss

Ex:
0+2015/04/24
17:45:31


Commandtosetthesystem
timeontheSDI12‐TBmodule.
Thiswillbeusedtoperform
thedailyandYearlyrainfall
resets.
IftheXDTcommandisissued
withoutanyarguments(eg.
aXDT!),thecurrenttimeis
returnedwithoutmodifying
theexistingtime.
Default=2012/01/0100:00.0
hrs

XDR
Read/Write
dailyrainfall
resettime
aXDR!
or
aXDR+hh:mm:ss!

Ex:
0XDR+!
or
0XDR+09:30:15

Resetdailyrainfallat
09:30.15hrseveryday.

a+hh:mm:ss

Ex:
0+09:30:15

Commandtoconfigurethe
dailyresettime.
Default=00:00.0hrs
XYR Read/Write
Yearly
rainfall
resettime
aXYR!
or
aXYR+mm/ddhh:mm:ss!

Ex:
0XYR+!
or
0XYR+05/2409:30:15
ResetYearlyrainfallon
May24at09:30.15hrs
everyyear.
a+mm/dd
hh:mm:ss

Ex:
0+05/24
09:30:15


Commandtoconfigurethe
yearlyresettime.
Default=01/0100:00.0hrs



SutronCorporationSDI‐TBUsersManual   Rev.1.1 5/24/2018 pg.12



CommandNameCommandResponseNotes
XBKTSZ
Read/Write
tipping
bucketsize
aXBKTSZ!
or
aXBKTSZ+<bucketsize>!

Ex:
0XBKTSZ!
or
0XBKTSZ+0.01!

Setthebucketsizeto
compute0.01inchesof
rainfallforeverytip.
a+<bucketsize>

where:
<bucketsize>=
Bucketsize

Ex:
0+0.01
Commandtoconfigurethe
bucketsize.
Thebucketsizeisusedto
convertbuckettipsinto
rainfall.Ifthecompensation
coefficients(XCOMP)arenot
provided,theneachtipis
equaltobucketsize.If
coefficientsareprovided,then
a3rdorderpolynomialisused
toconverttipsintorainfall.
Defaultvalue=0.01
XEDGE Read/Write
edge
aXEDGE!
or
aXEDGE+<edge>!
Where<edge>
=1(risingedge)
=0(fallingedge)

Ex:
0XEDGE!
or
0XEDGE+1!

ConfigurestheTipping
Bucketinputtoregistera
tipontherisingedge.
a+<edge>

where:
<edge>=new
edge
Ex:
0+1
Commandtoconfigurethe
tippingbucketinputedge.Ifa
fallingedgeisconfiguredthen
theinternalpullupresistoris
automaticallyactive,elsepull‐
downresistorisactivated.

Defaultvalue=0(pull‐up)



SutronCorporationSDI‐TBUsersManual   Rev.1.1 5/24/2018 pg.13



CommandNameCommandResponseNotes
XDBNC Read/Write
debouncing
duration
aXDBNC!
or
aXDBNC+<debounce_dura
tion>!
Where
<debounce_duration>=
newdebounceduration
0≤debounce_duration≤
255ms
Ex:
0XDBNC!
or
0XDBNC+30!
ConfigurestheTipping
Buckettoonlyregistera
tipiftheTB‐INlineisheld
intheactivestateforat
least30ms.
a+<debounce_d
uration>
Ex:
0+30
Commandtoconfigurethe
debouncedurationin
milliseconds.
Thisisusedtofilteroutnoisy
tippingbucketoutputs,sothat
theswitchingnoiseisnot
countedasatip.
TheTB‐INinputmustbeheld
intheactivestateforatleast
debounce_durationms.
Defaultvalue=15ms
XIDURRead/Write
Rainsample
duration
aXIDUR!
or
aXIDUR+<duration_minut
es>!
Ex:
0XIDUR!
or
0XIDUR+15!
Willreturnthetotal
rainfallinthelast15
minutes
A+<duration_mi
nutes>
Ex:
0+15
Amovingwindowkeepstrack
ofthetotalrainfallinthelast
duration_minutesminutes.
Max=20minutes.
Default=15mintes.
XRBOOTRebootthe
system
aXRBOOT+SDITB!a+OK
or
0+ERR
Rebootsthemoduleafter8
secs.Allinternalcounter/
accumulationvalueswillbe
lost.



SutronCorporationSDI‐TBUsersManual   Rev.1.1 5/24/2018 pg.14



CommandNameCommandResponseNotes
XCOMPRead/write
compensati
on
polynomial
coefficients.
aXCOMP!
or
aXCOMP+<k3>+<k2>+<k1
>+<k0>
where:
k3,k2,k1,k0are
coefficientsforathird
ordercompensation
polynomial
Ex:
0XCOMP!
or
0XCOMP+0.00000002‐
0.000003+0.0002+0.0092
a+<k3>+<k2>+<
k1>+<k0>

TheSDI‐TBimplementsa3rd
orderpolynomialto
compensateforheavyrainfall
rates.
Ifnocoefficientsareprovided,
eachtip=<bucket_size>.
Thepolynomialisoftheform
/  


Where=inchesofrainper
hour.
XYARead/Write
Yearly
accumulatio
n.
aXYA!
or
aXYA+<yearly_acc>!
<yearly_acc>=New
accumulationthisyear
Ex:
0XYA
or
0XYA+2.1!
a+<yearly_acc>
Ex:
0+1.2
Commandtoread/writethe
totalaccumulationforthis
rainyear.Thiscommandwill
resetthedailyaccumulation,
totalrawtipcount,
accumulationsincelast
measurementandyesterday’s
accumulation.





SutronCorporationSDI‐TBUsersManual   Rev.1.1 5/24/2018 pg.15



AppendixA:Specifications&OrderingInformation

MECHANICAL/ENVIRONMENTAL
Enclosure Pottedenclosureforhumidenvironments
Dimensions3x1.5x1.5inches
Weight ~60gms
Temperature‐40Cto+60C
Connector5pinscrewlessconnector

POWER
InputVoltage DC4v‐20v
Initial(capacitordischarged)Power
updelay
~2minutes
Internalbackuppowerruntime~10hours
Internalbackuppowerchargetime ~18hours
Internalbackuppowercharging
current
25mA(fullydischarged)to100uA(fullycharged)
QuiescentCurrent <100uA@12v(oncefullycharged)

COMMUNICTAION
Protocol SDI‐12v1.3(SDIcommunicationwillbedisabled
whenrunningoffinternalbackuppower)

ORDERINGINFORMATION



SutronCorporationSDI‐TBUsersManual   Rev.1.1 5/24/2018 pg.16



SDI‐TBSDI‐12tippingbucketinterfacewithinternal
backuppower.


AppendixB:CustomerServicePolicy
DearCustomer:
ThankyouformakingtheimportantdecisiontopurchaseSutronequipment.AllSutronequipmentis
manufacturedandtestedtothehighestqualitystandardsassetbySutron’sQualityAssuranceDepartment.Our
CustomerServiceRepresentativeshaveyearsofexperiencewithequipment,systems,andservices.Theyare
electronictechnicianswithfieldandapplicationsexperience,notjustwithatechnicalbackground.
CUSTOMERPHONESUPPORT
CustomerServiceRepresentativesroutinelyhandleawidevarietyofquestionseveryday.Ifquestionsarise,
pleasefeelfreetocontactmeoroneoftheCustomerServiceRepresentatives.Weareavailablefrom8:00amto
5:00pmMondaythroughFridayandwillbehappytotakeyourcall.
Wecananswermostsensorandinterfacequestionsonthefirstcall.Ifwecannotquicklyansweraquestionon
aninterface,wewillworkwithyouuntilwefindasolution.
Sometimesaproblemisapplicationrelated.Althoughweprideourselvesonhandling95%ofapplicationrelated
questionsoverthephone,wemaintainconstantcontactwithourIntegratedSystemsDivisionandEngineering
Divisionforadditionalassistance.
INTRODUCTORYTRAINING
TrainingisanimportantpartoftheSutronCustomerServicephilosophy.TheSutrontrainingpolicyissimple‐‐‐If
youbuySutronequipment,yougetSutrontraining!Withoutthepropertraining,youcannottakeadvantageof
thebenefitsandadvantagesthatSutronequipmentprovides.Weoftensupplyon‐siteintroductorytrainingat
yourfacilityfornocharge.Youprovidetheclassroom,students,equipment,andcoffee‐‐‐we'llprovidethe
instructor.
ON‐SITEVISITS
Ofcoursenotallproblemscanbefixedoverthephone.Sometimesacustomerneedsanon‐sitetechnicianto
identifysiterelatedproblemsortroubleshootanetwork.Sutroncanprovidetheseservicesatareasonablecost.
Callfordetails.IfyouwouldliketolearnmoreaboutSutronproductsemail[email protected]
Thanksagainforyourorder,

PaulDelisi
CustomerServiceManager
SutronCorporation

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SutronCorporationSDI‐TBUsersManual   Rev.1.1 5/24/2018 pg.17
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SutronCorporationSDI‐TBUsersManual   Rev.1.1
 5/24/2018 pg.18
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AppendixC:CommercialWarranty
SUTRONMANUFACTUREDEQUIPMENT
THESUTRONCORPORATIONWARRANTSthattheequipmentmanufacturedbyitsManufacturingDivisionshallconformtoapplicable
specificationsandshallremainfreefromdefectsinworkmanshipandmaterialforaperiodendingtwoyearsfromthedateofshipment
fromSutron’splant.
Sutron’sobligationunderthisWarrantyshallbelimitedtorepairatthefactory(22400DavisDrive,Sterling,VA20164)or,atSutron’s
option,replacementofthedefectiveproduct.InnoeventshallSutronberesponsibleforincidentalorconsequentialdamages,whether
ornotforeseeableorwhetherornotSutronhasknowledgeofthepossibilityofsuchdamages.ThisWarrantyshallnotapplytoproducts
thathavebeendamagedthroughnegligence,accident,misuseoractsofnaturesuchasfloods,fires,earthquakes,lightningstrikes,etc.
Sutron’sliability,whetherincontractorintort,arisingoutofwarrantiesorrepresentations,instructionsordefectsfromanycause,shall
belimitedexclusivelytorepairorreplacementpartsundertheaforesaidconditions.
SutronrequiresthereturnofthedefectiveelectronicproductsorpartstothefactorytoestablishclaimunderthisWarranty.The
customershallpre‐paytransportationchargestothefactory.Sutronshallpaytransportationchargesforthereturnoftherepaired
equipmenttothecustomerwhenthevalidityofthedamageclaimhasbeenestablished.Otherwise,Sutronwillpre‐payshipmentandbill
theamounttothecustomer.Allshipmentsshallbeaccomplishedbybest‐waysurfacefreight.
SutronshallinnoeventassumeanyresponsibilityforrepairsoralterationsmadeotherthanbySutron.Anyproductsrepairedor
replacedunderthisWarrantywillbewarrantedforthebalanceoftheWarrantyperiodorforaperiodof180daysfromtherepair
shipmentdate,whicheverisgreater.Productsrepairedatcostwillbewarrantedfor90daysfromthedateofshipment.
NON‐SUTRONMANUFACTUREDEQUIPMENT
TheaboveWarrantyappliesonlytoproductsmanufacturedbySutron.Equipmentprovided,butnotmanufacturedbySutron,is
warrantedandwillberepairedtotheextentofandaccordingtothecurrenttermsandconditionsoftherespectiveequipment
manufacturers.
EXTENDEDWARRANTYANDON‐SITEMAINTENANCE
Extendedwarrantyandon‐sitemaintenancecontractsareavailable.PricequotationsmaybeobtainedfromSutronCustomerService
Representatives.
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