DISTELL Torrymeter User manual
USERMANUAL
DISTELLFISHFRESHNESSMETER
ModelTorrymeter
©DISTELL.Com,December2010(Version2.8)–forusewithv1firmware
distell‐ing.pres.part.verb.1.todistell.2.to
rapidlyanalysefatcontentoffoodproductsusing
microwavetechnology.
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Contents
Introduction........................................................................................................................................5
Freshnessoffishanditsmeasurement.......................................................................................................................5
FreshnessMeterbenefits............................................................................................................................................5
Generaldescription.....................................................................................................................................................6
Principleofoperation..................................................................................................................................................6
Technicaldata.............................................................................................................................................................7
Step‐by‐stepguide..............................................................................................................................8
TheFreshnessMeterkit..............................................................................................................................................8
MeterUnit..................................................................................................................................................................8
Data/powerSocket.............................................................................................................................................8
Sensor..................................................................................................................................................................8
ReadButton(Yes)................................................................................................................................................8
ResetButton(No)................................................................................................................................................8
Datacable...................................................................................................................................................................8
CD‐ROM......................................................................................................................................................................9
Usermanual................................................................................................................................................................9
Carrycase...................................................................................................................................................................9
Powersupply/charger...............................................................................................................................................9
ChargingtheMeter..............................................................................................................................................9
Gettingstarted..................................................................................................................................10
Switchon..................................................................................................................................................................10
Measuringproductsamples......................................................................................................................................10
Comparingthemeterwithlaboratoryanalysis.........................................................................................................11
MenuStructure.........................................................................................................................................................12
Productmenu....................................................................................................................................................12
Researchmenu..................................................................................................................................................13
Samplesmenu....................................................................................................................................................13
Downloadmenu.................................................................................................................................................13
AddProductoption............................................................................................................................................14
Date&Timemenu.............................................................................................................................................14
Usagerecommendations...................................................................................................................15
Usingthemeterinqualitycontrol.............................................................................................................................15
Sampling............................................................................................................................................................15
FreshnessMeterperformance...................................................................................................................................15
Therelationshipbetweenmeterreadingsandothermeasuresoffreshness.....................................................15
Effectsofhandlingandprocessing.....................................................................................................................17
Effectsoffreezingandbrining............................................................................................................................17
Metercareandservice..............................................................................................................................................18
Cleaningandgeneralcare..................................................................................................................................18
Beforecallingforservice....................................................................................................................................18
Warrantyandservice.........................................................................................................................................18
DataManagementSystem................................................................................................................19
Installation................................................................................................................................................................19
Requirements.....................................................................................................................................................19
InstallingtheDMS..............................................................................................................................................19
RunningtheDMS......................................................................................................................................................19
HistoricalDataDownload.........................................................................................................................................19
Step1:ConnectingtheMeter............................................................................................................................19
Step2:ConfiguretheDMS.................................................................................................................................19
Step3:Initiatethedownloadfromthemeter....................................................................................................20
RealTimeDataDownload.........................................................................................................................................20
Enablingreal‐timedatadownload.....................................................................................................................21
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Annotatingthedata.................................................................................................................................................21
DMSdatafiles..........................................................................................................................................................21
Printingdata.............................................................................................................................................................21
Exportingdata..........................................................................................................................................................21
DataManagementsoftwareHelp............................................................................................................................21
Advancedtopics.......................................................................................................................................................21
Organolepticcharts..........................................................................................................................22
Cod,boxed................................................................................................................................................................23
Cod,normalhandling...............................................................................................................................................24
Codfillets,skin‐on(skinside)....................................................................................................................................25
Codfillets,boneside.................................................................................................................................................26
Haddock&Whiting,boxed.......................................................................................................................................27
Haddock&Whiting,normalhandling.......................................................................................................................28
Saithe,boxed............................................................................................................................................................29
Saithe,normalhandling............................................................................................................................................30
Plaice,boxed............................................................................................................................................................31
Place,normalhandling.............................................................................................................................................32
Redfish,boxed..........................................................................................................................................................33
Redfish,normalhandling..........................................................................................................................................34
Herring,5%fat,boxed,unhandled...........................................................................................................................35
Herring,10%fat,boxed,unhandled.........................................................................................................................36
Herring,15%fat,boxed,unhandled.........................................................................................................................37
Herring,20%fat,boxed,unhandled.........................................................................................................................38
Herring,25%fat,boxed,unhandled.........................................................................................................................39
Herring,30%fat,boxed,unhandled.........................................................................................................................40
Mackerel,8%fat,boxed,unhandled.........................................................................................................................41
Mackerel,13%fat,boxed,unhandled.......................................................................................................................42
Salmon,normalhandling..........................................................................................................................................43
Bluewhiting,boxed..................................................................................................................................................44
Bluewhiting,normalhandling..................................................................................................................................45
Chisawasawa,normalhandling................................................................................................................................46
Ladyfish,normalhandling........................................................................................................................................47
Seabream(dentexspp.),normalhandling...............................................................................................................48
Seabream(pagellusspp.),normalhandling.............................................................................................................49
Spanishmackerel,normalhandling..........................................................................................................................50
Tilapia,normalhandling...........................................................................................................................................51
Guidanceforanglingclubcompetitions............................................................................................52
ContactDetails.................................................................................................................................53
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Introduction
Freshnessoffishanditsmeasurement
Fishisahighlyperishablecommodity.Whennewlycaughtithaspleasant,sweetflavoursthatarehighly
acceptable.Onstoragetheseflavoursareprogressivelylostandthoughthefishisacceptable,itisnot
ofsuchhighquality.Furtherstorageproducesoffflavours,andultimatelythesebecomesostrongthat
thefishisunfittoeat.
Fishisgenerallystoredandtransportedinice,and,undertheseconditionsspeciesfromarcticor
temperatewaterswillreachtheunfitstatewithinabouttwoweeks.Tropicalfishcanbeheldsomewhat
longer.Spoilageismuchfasterifthefishisnotheldatchilltemperatures.Itisthereforeimportantfor
anyoneconcernedwithqualityoffishtobeabletomeasureitsfreshnessi.e.theamountof
deteriorationthathasoccurredsinceitwascaught.
Traditionally,freshnesshasbeenassessedbysensorymethods;usingthehumansensesofsight,smell
andtouch.Thisapproachgivesanimmediateappraisalofqualitywithoutdamagetothefish.
However,therearesomedifficulties.Trainedandexperiencedstaffisrequired,andthistrainingtakesa
longtime.Itisnoteasytomakesensoryassessmentquantitative.Thechangesoccurringduring
spoilagecanbedescribedandcodified,butindividualsmayinterpretthesedescriptionssomewhat
differently.Thoughasinglejudgemaybeconsistentwithinhimself,differentjudgeswillvaryamong
themselves.
Thismakesitdifficulttoestablishstandardsthatcanbeappliedindifferentlocations,andbydifferent
assessors.
Thereisthereforeaneedforobjectivemethodsformeasuringfreshnessthatdonotdependonthe
subjectiveopinionofhumanjudges.Severalchemicalproceduresareinuseforthispurpose,butall
sufferfromcommondisadvantagesinrespecttoqualitycontrolwithintheindustrialenvironment,in
thattheyaresomewhatslowtocarryout,whereasqualitycontrollersandinspectorsusuallyrequirean
immediateanswer.Theanalysisrequireslaboratoryfacilitiesandappropriatelyqualifiedstaff,afeature
whichrendersthemethodsunsuitableforfieldwork,andexpensiveforfactoryuse.Themethodsare
destructiveandthedamagedfishsamplesarenolongerfitforprocessing.
Generally,aqualitycontrollerorinspectorneedstoevaluatethefreshnessofabatchoffishratherthan
oneindividualsample.Anappropriatenumberoffisharetaken,thefishevaluatedseparatelyandthe
averageofthebatchcalculated.Therecordingandcalculationrequired,thoughsimple,are
inconvenienttocarryoutatthemarketorinthefactory.
Thereistherefore,arequirementforarapidandobjectivemethodformeasuringfishfreshnessina
widerangeofconditions.Themethodshouldbeaccessibletountrainedstaffandnon‐destructivein
use.Preferablyitshouldalsoallowbatchgradingwithaminimumofcomputationandrecordkeeping.
TheFishFreshnessMeter,orTorrymeter,hasbeendevelopedtomeettheserequirements.
FreshnessMeterbenefits
TheFishFreshnessMeter,whenusedwithorganolepticcharts,eliminatestheuncertainty,delayand
costpreviouslyincurredbysendingfishsamplestoatestlaboratory.Itcanbeusedoutoftheboxon
known,calibratedfishspecies,andafterasimplecalibrationprocedurefornewspecies.
Thefollowingsectionsofthemanualexplainfullyhowtousethemeterandorganolepticcharts.Before
these,itwillbeusefultohaveanintroductiontotheirunderlyingconcepts.
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Forknownspecies–oneforwhichanorganolepticchartexists–theprocedureissimple.Takeameter
readingfromasampleofyourrequiredspecies;theresult,measuredontheTorryFreshnessScale,
shouldbebetween16forfreshand1forspoiled.Thenrefertotherelevantorganolepticchartforan
interpretationofthemeterreadinganditsimplicationforthefreshnessofyoursample.
Forexample,ifyouwishtosamplecodwhichisboxedbetweencatchandport,refertothefirstchartin
‘Organolepticcharts’.Thischartshowsthatameterreadingof16representsafishoflessthan2days
old.Areadingof8wouldindicatethatthefishwas10daysoldandareadingofbelow3wouldindicate
thatthefishwasmorethan18daysold,andspoiled.
Ifthespeciesisnotknownandhasnoorganolepticchart,youcanperformacustomcalibrationexercise
inwhichyougenerateachartforfuturereference.Todothis,takeasetofreadingsforthefishasit
decaysfromfreshtospoiled.Thismaygiveareasonablesetofreadingsfromsomewherenear16
(fresh)to3orbelowwhenspoiled.Ifthisisinfactthecase,thereadingscanbeusedtowriteintoan
organolepticchartwhichbecomesthereferenceforthenewspecies.
Alternativelyhoweveryoumayfindthattherangeofreadingsasthefishdecaysfromfreshtoputridis
toonarrowforusefulinterpretation.Forexampleyoumayseeaninitialreadingof12whenfreshand8
whenspoiled.Theansweristousethefullinternalrangeofthemeter,whichhasmuchmoreresolution
availablethanthescalesavailablewiththeTORRY‐1(0.1to18.5)orTORRY‐STD(1to18)scales.The
internalrangeisaccessedusingtheRESEARCH‐1calibration,whichoffersarangeof0.1toabove99.9.
Bytakingasecondsetofreadingsusingthishigherresolutionyouwillbeabletoobtainasetof
meaningfullydifferentiatedreadingsoverthenarrowrangeofthe12–8exampleabove.Having
obtainedareferencedatasetofsuchreadingsovertheperiodfromfreshtoputridyoucan:
a. Simplycontinueusingthisdatasetasareferenceforfuturemeasurementsofthesame
species,or
b. Loadthedataintoaspreadsheetforfurtheranalysisorreference,or
c. GenerateanAnalysisDatasetofequaldailydecrementsfrom18to1,andusethiswithinthe
DataManagementSystemtoscaletheReferenceDatasetreadings.Thescaledoutput
datasetbecomesthenewcustomcalibrationforthenewspecies;itcanbestoredinthe
meterandenteredintoanewOrganolepticChart.
YoucanrefertotheFreshnessMeterTechnicalManual,ontheCD‐ROMandontheDistellwebsite,for
moreinformationoncustomcalibrations.
Generaldescription
ThislatestmodeloftheFishFreshnessMeteriscompact,robust,fullyportableandsuitableforany
normalapplicationwithinfishprocessingindustrymarkets,processingfactoriesorqualitycontrol
laboratories.Itprovidesrapidmeasurementsandissimpletouse.
ThefreshnessofthefishisindicatedontheLCDdisplay.
Themetercanbesettomeasurefrom1‐16fish.Themenudrivensoftwarewillsumthereadingsofall
thesamplesandthendisplaytheiraveragevalue.Themeterismostaccurateinthismode.
Generallythemeasurementscanbetakenwithoutdisturbingthefishintheircontainers,andthetesting
doesnotdamageormarkthesamplesinanyway.
Principleofoperation
TheoriginalresearchleadingtothedevelopmentoftheFishFreshnessMeterwascarriedoutatTorry
ResearchStation,inAberdeen,Scotland.
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Itwasfoundthatcertaindielectricpropertiesofthefishskinandmusclealterinasystematicwayduring
spoilage,astissuecomponentsdegrade.Thesealterations,occurringatmicroscopiclevel,arestrongly
associatedwiththegrosschangesinappearance,odour,texture,andflavourwhichtakeplaceduring
spoilageandwhicharenormallyusedtojudgefreshness.Hence,determinationoftheappropriate
dielectricpropertiesgivesameasurementofthefreshnessofthefish.
Thebaseoftheinstrument(sensinghead)hastwopairsofconcentricallyarrangedelectrodes.This
sensingheadisapplieddirectlyontotheskinofthefish.Analternatingcurrentispassedthroughthe
fish,betweentheouterpairsofelectrodesandtheresultingvoltagesensedbytheinnerpair.The
phaseanglebetweenthecurrentandvoltageismeasuredandconvertedelectronicallytoallowdigital
displayonaconvenientscaleintherange0‐18.Thephaseangleandhencethemeterreading
decreaseswithspoilage.Thecurrentpassedthroughthefishisapproximately1milliampandsocannot
harmtheoperatororaffectthefish.
Betweenthemeasuringelectrodesaretwoauxiliaryelectrodes.Theseelectrodes,inconjunctionwith
oneofthecarbonelectrodes,sensewhetherthereispropercontactwiththefish.Thefishsensing
devicepreventsreadingsbeingtakenunderinappropriateconditionse.g.inair,orinice.Sincethe
phaseangledependsontemperatureaswellasfreshness,thereadingdisplayedbytheinstrumentmust
becorrectedtothevalueitwouldshowatareferencetemperatureof0°C.
Themeterispoweredbyrechargeablebatterieswithintheinstrument.Theyhavesufficientcapacityto
allowafullworkingday’soperation.
Technicaldata
ThisUserManualdoesnotcoverthetechnicalsideoftheFreshnessMeteringreatdepth.Youcanfind
acopyofourTechnicalManualontheCD‐ROMthatissuppliedwiththemeter,oryoucandownloada
copyfromourwebsite.ThiswillhelpyouexplorethetechnicalaspectsoftheFreshnessMeter’s
operation,aswellashowtocreatecustomcalibrations.
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Step‐by‐stepguide
TheFreshnessMeterkit
YourFreshnessMeterkitcomprisesthefollowingitems:
•Meterunit
•Powersupply/charger
•USBdatacable
•CD‐ROM
•Usermanual
•Carrycase
Pleasetakegoodcareofthemeter.Itisameasurement
instrumentandshouldbehandledcarefully.Themetershouldbecleanedandstoredinitscaseafter
use.
MeterUnit
Data/powerSocket
The7‐waysocketonthesideofthemeter
servesthreefunctions:
•Datadownloadsocket,for
transferringdatatoPC,usingcable
supplied.
•Allowsthemetertorunonexternal
power
•Usedforcharginginternalbatteries
Sensor
Thesensorhastwooutercarbonelectrodesfor
measuringfreshness,andtwoinnermetal
electrodesforsensingcontactwiththeskinof
thefish.
Itisagoodideatowipethesensorclean
betweenreadings,sinceitiseasyforfishscalestosticktothesensorandaffectreadings.
ReadButton(Yes)
•Pressandholdthisbuttontotakeareading;
•Presstoanswer‘Yes’toanyYes/Noquestiononthedisplay.
ResetButton(No)
•Presstoresetthemeasurementroutine,ortoabortanincompleteseriesofreadings;
•Presstoanswer‘No’toanyYes/Noquestiononthedisplay.
Datacable
Alwaysusethedatacablesuppliedfordownloadingtocomputer.Connectthe7‐wayplugtooutleton
meterandtheotherenddirectlyintoaUSBportonyourcomputer.
Sensor
Data/powersocket
Powerswitch
LCDDisplay
Read/YesbuttonReset/Nobutton
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CD‐ROM
TheCDcontainstheusermanuals,DataManagementSystem,calibrationcharts,andotheruseful
information.
Usermanual
Ahardcopyoftheusermanualandthecalibrationcertificateisincluded.
Carrycase
TheFreshnessMeterkitissuppliedinarobustcarrycase,andcomescompletewithtwokeysfor
securityofyourFreshnessMeter.
Powersupply/charger
Onlytheunitsuppliedwithyourkitshouldbeusedtocharge
thebatterypack,orpowerthemeter.Thisisconnectedtothe
7‐wayoutletonthemeter.Thechargersupplyunitsimplyplugs
intothemainssocket,acceptinginputmainsvoltagefrom
110v–240vAC,50–60Hz.Thechargerunitcomescomplete
withvariousplugconfigurationsforusearoundtheworld.
AredLEDwillilluminatewhencharger/powersupplyis
switchedon.Thebatterypackshouldbefullychargedaftera
periodof12hours.Whenchargingiscomplete,firstdisconnect
thechargerfromthemainsandthenfromthemeter.
Thepowersupply/chargercanalsobeusedtopowerthe
meterduringusewhilealsochargingtheinternalbatteriesatareducedrate.
ChargingtheMeter
NotesonchargingtheMeter:
•Insertpowerunitconnectorplugcarefullyinto
metersocket(toinsert,turnpluggentlyuntilthe
plugslidesintotheconnector.
•Metershouldbechargedforafull12hoursbefore
useifpossible.
•Alwaysensurethatmeterisswitched“OFF”before
charging.
•Whenchargingiscomplete,firstdisconnectthe
powerunitfromthemainsandthenfromthe
meter.
•Alwaysfitdust/moisturecapinplacebefore
commencingwork,especiallyinwetenvironments.
Note:UseonlythisDistellpowerunitforbatterychargingormeterpower.Donotuseexcessiveforce
whenpluggingthepowerunitintothemetersocket.
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FreshnessMeterUserManualPage10
Gettingstarted
Verifythatbatteryhasbeencharged.
Switchon
SwitchontheMeterandallowthemetertocyclethroughitsstartupprocedure.
Partofthestartupprocedureistoshowhowmanyreadingsarecurrentlystoredinthemeter.Youmay
wishtodownloadanderaseanystoredreadingsbeforetakingnewmeasurements.Youcanfindout
aboutthedownloadprocedureinthe‘DataManagementSystem’section.
Afteraround15secondsthemeterisreadyforuse.Thedisplaywillshowthelastcalibrationsetting
used,andwilllooksomethingliketheexamplebelow:
CalibrationSetting
TORRY-1
Y SN=3 N
Yes Numberofsamples used
tocalculateaverage
No
Measuringproductsamples
Haveacopyoftheorganolepticchartsathand.Forbestaccuracyalwaysfollowthemeasurement
recommendationsinthismanual.
Beforestartingwerecommendyoucarryoutsomechecks:
1. Checkthatyouhavesetthecorrectnumberofsamples,from1to16,fromtheSamplesmenu.
2. Checkthatyouhaveselectedthecorrectcalibrationsettingonthemeterforthefishbeing
sampled.
3. Checktoensurethatyouhavepreparedorhavebeensuppliedwithanorganolepticchartsuitable
forthisfishspecies.
4. Selectthefishsamplesatrandomfromthebatch.Whereyouaretakingfishsamplesfromavaried
batch,thesamplesshouldbegroupedaccordingtosize(length/weight).
5. Checkthattemperatureofthefishtobemeasuredisbetween0and10°C,withnoicecrystals
presentinthesamples.
Themeasurementprocedureisoutlinedasfollows:
1. Ensurethatthesensorisplacedfirmlyagainsttheskinofthefish,thusensuringthatthereareno
airpocketsbetweenthesensorandthesampletobemeasured.PresstheRead/Yesbutton;the
Meterwillconfirmcontactwiththefish,takethemeasurement,displayandstorethevalue.
2. Ifyousee‘NoContact’displayedonthemeterthencheckthatthesensorismakinggoodcontact
withtheskinofthefish.Themeterwillnottakeanyreadingsuntilitdetectsgoodskincontact.
3. Forbestresultsbeconsistent.Alwaysplacethesensoronthesamepartofeachfish.Thiswill
ensurethatyouachieveoptimum,comparableresults.Itisnormaltoexperiencevariabilityinthe
individualreadingswhentakenatdifferentpartsofthefish.Notealsothatdifferentpartsofthe
fishwillspoilatdifferentrates,dependinguponthelevelofbacteriologicalactivitypresentwithin
thefish.
4. Onesetofreadingsshouldbetakenfromeachfish,attherecommendedmeasurementsites.The
resultswillbestoredintheFreshnessMeterforlaterdownloading.
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5. Placethebaseofthemeterfirmlyonthefishsothatitliesflatagainstthesurfaceandparallelto
thelaterallineatathick,fleshypartofthefish.Thebestpositionisattheshoulderareawithinthe
firstthirdofthefish,intheregionofthelateralline,asshownintheillustrationbelow.Avoidthe
headandbellycavityregions.
6. Ifthisisthefirstreadingafterthemeterhasbeeninawarmplace,holdtheprobeheadagainstthe
fishfor10‐20seconds,toallowthesensortocooldownbeforepressingtheRead/Yesbutton.
7. Tomeasureindividualfish,settheFreshnessMetertoread3samples(seethe‘MenuStructure’
sectionfordetails),placethemeterattherecommendedmeasurementsite,andtake
measurementsthreetimes.Theindividualvaluesandtheaveragevaluewillbestoredinthemeter
fordownloading.WhentheaveragevalueisshownonthedisplaypressRead/Yestotakemore
readingsonadifferentfishorpressReset/Notofinish.
8. AvoidpressingtheREADbuttonwhenthemeterisnotincontactwithafish.Ifthereisathicklayer
ofslimeontheprobeheaditmayconductenoughcurrenttoactasiftheelectrodeswerein
contactwithafishandameasurementwillbemade.
9. Switchthemeteroffafterusetoretainthechargeinthebattery.
Normallythreereadingsarerecommended.Wehavefoundthatthisgivesthebestbalancebetween
accuracyandspeed.Youcanchangethenumberofreadingsthatthemeterwilltakebeforeaveraging
byusingthe‘Samples’menuoption.Seethe‘MenuStructure’sectionformoredetails.
TheFreshnessMetercanstoreupto1000setsofreadings.ThesecanbedownloadedtoaPCrunning
theDataManagementSystem.Seethe‘DataManagementSystem’sectionformoreinformationon
howtodothis.Thereisalsoanoptiontodownloadthedatainrealtime,i.e.asthereadingsaretaken,
andthisiscoveredinthesamesection.
Comparingthemeterwithlaboratoryanalysis
IfyouwishtocomparetheresultsachievedusingtheFreshnessMeterwithalaboratoryprocedure,itis
importantthattheentirefishcarcasssampleispackagedandsenttothelaboratoryfortheanalysis.
Thesampleshouldbestoredinasealedpolythenebagimmediatelyaftermeasurementandthe
temperatureofthesampleshouldbemaintainedascloseto0°Caspossible.Thiswillensurethat
spoilageofthesampleisreducedasfaraspossible.
Important:Donotallowthesampletofreeze.
Thewholecarcassofthefish/filletshouldbereceivedatthelaboratoryproperlypackedandsealed,
andthecurrent‘agefromdeath’ofthesampleshouldbeascertainedusingstandardlaboratory
methods,e.g.TVBN,etc.
IftheresultsfromtheLaboratorydonotcomparefavourablywithyourmetercheckthemeter‘suseas
follows:
•IstheoperatorproficientintheuseoftheFishFreshnessMeter?
•IsthefishspeciesthesameasthatquotedonyourOrganolepticChart?
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•Checktheproductforspeciesidentification,measurementtechnique,sizeandpreparation.
Checkthelaboratoryprocedureasfollows:
•Verifytheanalyticalmethodbeingused
•CheckthatthesamplepreparationwasOK
ThisisjustashortchecklistonhowtouseandcomparetheFreshnessMeterwithothermethods.
RememberthattheprimarypurposeinusingtheFreshnessMeteristoscreenalotofproductfor
uniformity,specificationandshelflife,andtoidentifyfishthathasbeenfrozenorirradiated.
Duringthemeasurementprocess,finiteaccuracyisnottheobjective.Theobjectistotryandensure
thatthebulkoftheday'srawmaterialsandprocessedproductionmeetswithyourspecificationstime
aftertime.
If,afterthesechecksthereisstillasignificantdifference,pleasecontactDistellforadviceandhelp.
NotethattheDistellwebsitehasacomprehensiveFrequentlyAskedQuestionssectionaswellas
technicalinformationontheFreshnessMeter.
MenuStructure
Whenthestandardmeasurementdisplayisshown(seetheexampleatthestartofthischapter)youcan
accessthemenubypressingtheReset/Nobutton.TheChoicesmenuscreenwillappearintheorder
shownbelow.Therearesixoptions.CyclethroughtheoptionsbypressingReset/Nountilthecorrect
oneisdisplayedthenpressRead/Yes.
Productmenu
IntheProductmenuyoucanchoosewhichoftheproductcalibrationsettingsyouwishtouse.Simply
choosethecalibrationthatcorrespondswiththetypeofmeasurementyouwishtouse.
CHOICES MENU
Y PRODUCT N
TORRY‐1TORRYSTD OTHER
ChoicesMenu
PRODUCTRESEARCHSAMPLESSETTIMEDOWNLOADADDPRODUCT
TORRY STD
Y SN=3 N
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Researchmenu
IntheResearchmenuyoucanchoosewhichoftheresearchcalibrationsettingsyouwishtouse.The
FreshnessMeterisnormallysuppliedwiththefollowingsettings:RESEARCH‐1,FISH‐1,FISH‐2...FISH‐5.
TheRESEARCH‐1calibrationsettingisusedtocreateanewcalibrationsetting.
SettingsFISH‐1toFISH‐5canbeprogrammedwithyourcustomcalibrationdatawhererequired.Full
detailsareavailableinourTechnicalGuide,whichisavailableontheCD‐ROMandfromourwebsite.
Samplesmenu
Forgreatestaccuracyyoushoulduseeightsamplesperfishandmeasureeightfishfromabatch.For
singlefishwerecommendthattheFreshnessMeterbesetupforthreesamplesperfish.Inbothcases,
allthemeasurementsshouldbetakenatthesamesiteonthefish.Youcanchoosebetween1and16
sampleshere.
Note:ifyouchoose16samplesthentheindividualsamplevalueswillnotbereportedastheyaretaken,
i.e.thesamplingisdone‘blind’.Theseindividualreadingsarestoredinthemeterandcanbeseen
whendownloadedtotheDataManagementSystem.
Downloadmenu
TheDownloadmenuallowsyoutosendanystoredsampledatatoaconnectedPCrunningtheData
ManagementSystem.TheDMSisdocumentedlaterinthisguide,andthedownloadprocedureis
coveredthere.
CHOICES MENU
Y DOWNLOAD N
(Ifnodatahas
beenrecorded
)
(Ifdataisready
fordownload
)
NoDataStandardD/L
CHOICES MENU
Y SAMPLES N
Samples=1Samples=2 Samples=3 ...Samples=16
CHOICES MENU
Y RESEARCH N
FISH‐5RESEARCH‐1FISH‐1FISH‐2FISH‐3FISH‐4
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AddProductoption
Usingthismenuprovidestheabilitytoprogrammethemeterwithadditionalcalibrations.Thisfacilityis
especiallyusefulforthosewhowishtorefineexistingmetercalibrationsorcreateanewcalibration
settingbasedontheirowndata.
FullinstructionsonhowtousethisfacilityareintheTechnicalManual,availableontheCD‐ROMand
fromtheDistellwebsite.
Date&Timemenu
Youshouldcheckthedateandtimewhenyoufirstreceivethemeter,andupdateitifnecessary.Each
samplethatisrecordedbythemeterhasadateandtimestamp,soitisrecommendedthatthedate
andtimebekeptaccurate.
Thiswillthenensurethatalldownloadsreflectthecorrectdateandtime.
Notethatifameterisconfiguredasarentalmeterthenthisoptionwillnotbeavailable.Youcanread
moreaboutrentalkeysathttp://www.distell.com/downloads/rentalkey.pdf.
CHOICES MENU
Y SET TIME N
Minutes
Hours
Day
Month
Year
CHOICES MENU
Y ADD PRODUCT N
Waitingdata
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FreshnessMeterUserManualPage15
Usagerecommendations
Usingthemeterinqualitycontrol
Sampling
TheFishFreshnessMeterwasdesignedwiththeneedsofthequalitycontrollerinmind.Theterm
‘qualitycontroller’ismeanttoincludeofficialsresponsibleforpublichealthinspectionorenforcement
ofmandatoryregulationsconcerningquality,aswellaspersonsconcernedwithqualitycontrolin
industryandcommerce.Inatypicalsituation,acontrollerisrequiredtotestbatchesoffishthatare
beinginspected,soldorprocessedasaunit,andforthisasuitablesamplemustbetaken.Themeter
simplifiesthisprocessofassessingabatchbysampling.
Ifthefreshnessofindividualfishwithinabatchismeasuredwiththemeter,itwillbefoundtovary.
Thisfish‐to‐fishvariationinmeterreadingsiscausedbytwofactors:‐
a. Variationinintrinsicfreshnessamongindividualfish.
b. Variationofmeterreadingsamongfishofthesamefreshness.
Bothareexpressionsofthevariabilityofbiologicalorganisms.Abatchoffishcaughtatthesametime
andhandledandstoredidenticallywillspoilatslightlydifferentratesbecauseofvariationsinchemical
constitutionandbacterialactivity.Hencetheindividualfishinthebatchwillhavearangeoffreshness;
arangethatwilltendtoincreaseasspoilageincreases.
Themeterreadingsthemselvesarenotdirectmeasuresoffreshness,asdefinedinsensoryterms,but
arestronglyassociatedwithit.Therelationshipbetweenmeterreadingsandfreshnessasmeasuredby
asensorypanelwillonceagainbedifferentforeachindividualfish.Forthisreasonitisnot
recommendedthatthemeterbeusedtoassessthefreshnessofsinglefish,exceptwithinratherwide
limits.
Thesedeviationsfromaveragebehaviourtendtocanceloutwhenthemeansofsamplesfrombatches
aretaken,andthebiggerthesamplethebetterthecorrelationbetweenthemeanmeterreadingand
freshnessscore.Itfollowsfromsamplingtheorythatthenumberoffishwhichoughttobesampled
fromabatchdependsmainlyonthedesiredprecisionofthemeanscore.Italsofollowsthat,provided
thebatchislargeenough,therequiredsamplesizedoesnotdependonthesizeofthebatch.From
observationsmade,ithasbeendecidedtouseasamplesizeofeightfishasthebasisfortheaveraging
intheFishFreshnessMeter.
Inmostmarketinganddistributionsystemsthefishareheldincontainerswithacapacityof50Kg.
Severalcontainersconstituteabatch.Inthissituationfishfromasmanycontainersaspossibleshould
besampledi.e.onefromeachcontainerifthebatchhaseightormore,fourfromeachcontainerifthat
isallthereisinthebatch.Ifthecontrollerorinspectorwantsgreaterconfidenceinthebatchaverage,
morethanonesetofeightfishcanbesampled,andagrandaverageoftheresultscalculated.
Notethattheprecisionofanaveragedresultincreasesonlyasthesquarerootofthesamplesize.An
averageof64readingsisonlytwiceaspreciseasanaverageof8readings.
FreshnessMeterperformance
Therelationshipbetweenmeterreadingsandothermeasuresoffreshness
Therearemanywaysofexpressingthefreshnessoffish.Perhapsthesimplestforfishheldiniceisto
quotethestoragetime.However,asiswellknown,theinitialqualityofmanyspeciesoffishvarieswith
theseasonsoftheyear,duetosuchfactorsasthespawningcycleandtheavailabilityoffood.These
factorsalsoaffecttherateofspoilage,sothatthetimeiniceisnotnecessarilyagoodmeasureof
...theartofdistell‐ing...
FreshnessMeterUserManualPage16
freshnessunlessrelatedtothetimeoftheyear.Ithasbeenfoundthatabetterwayofexpressing
freshnessistoconstructasystemofnumericalscalesbaseduponmethodsofobjectivesensory
assessmentbyatrainedtastepanel.Suchasystemisbetterbecauseitisdirectlyrelatedtoeating
qualityratherthandependingonknowledgeofthestorageconditions.
Oftenthefishisallocatedtooneofafewqualitygradesbasedondefinitionsinsensoryterms.An
exampleofthisistheEuropeanEconomicCommunity’ssystemofgradingfishformarketingpurposes.
Anextremeformofthistypeisthepublichealthinspector’sgradingintofitandunfit.Aquality
controllermaynotevenconsciouslyputascoreoragradetoabatch,butmustacceptorrejectitfor
thepurposeinmind.
Inpracticethequalitycontrollerinindustryadoptsthemostconvenientsystemforhispurpose,butan
officialinspectorwillhavetousewhateverislaiddownintheregulations.Itisquitepossibletodefine
grades,boundariesoracceptance/rejectionrangesoffreshnessforvariousoutlets,etc,intermsof
meterreadingsandindeedthisisagoodwayofusingtheinstrument.However,untiltheuserisfamiliar
withtheinstrument,itisbesttoemployitinparallelwiththeaccustomedmethodofassessing
freshness.Aftersomeexperience,therelationshipbetweenthequalitylevelstheuserisfamiliarwith
andthemeterreadingscanbeestablished.Nevertheless,themetercanbeusedbyanunskilled
operatorafterverylittleinstruction.
AsaguidetothevaluesthatcanbeexpectedfromsomespeciesofinteresttoEuropeanFish
Processors,averagereadingsfordifferentlevelsoffreshnessareshowninthesetoforganolepticcharts
inthe‘Organolepticcharts’section.TheseresultswereobtainedbyTorryResearchStationattheir
laboratoriesinAberdeenandHull,andatvariousfishingportsintheUK.Thesensoryscoresarebased
onthescalesusedatTorryResearchStation,andhavebeendescribedintheirpublications.
Thesescaleswereinterpretedasfollows:
•Perfectlyfreshfishisgivenascoreof10.
•Goodqualityfishhasascoreof6ormore.
•Belowascoreof4,thefishareconsideredunfittoeat.
Thesefreshnessscoresareonlyaroughguide.Usersarestronglyadvisedtoobtainequivalentlevels
fromscoresgivenbytheirowntrainedpanel,asthescoresmaybebasedupondifferentcriteria,or
obtainedunderdifferentconditions,fromthoseobtainedbyTorryResearchStationandDistell.
Forcomparison,theapproximatenumberofdaysofstorageinicewhichwouldcausethefishtoreacha
givenfreshnessscoreisalsoincludedinthecharts.Anexplanationofthedifferentcolumnsofmeter
readingsisgiveninthenextsection.
Theexamplesgivenaretypicaldemersalfish.Thesituationwithfishofhighandvariablefatcontentis
rathermorecomplex,andtherelationshipsbetweenthemeterreadingsandsensoryscoreshavenot
yetbeenmadeclear.However,extensiveworkcarriedoutbythestaffofTorryResearchStationwith
herringhasestablishedthatthemannerinwhichmeterreadingsvarywithtimeofstorageiniceisvery
dependenton:
a. Thefatcontentofthefish.
b. Whetherornotitisicedimmediatelyaftercatching.
c. Theextenttowhichitissubjectedtohandling.
Theorganolepticchartsshowtheapproximateageinicecorrespondingtogivenmeterreadingsfor
boxedherringofvariousfatcontents.Theage‐in‐iceisvalidonlyforfishwhichhasbeenboxedandiced
immediatelyaftercatching.Delayedicingalwaysgivesrisetolowermeterreadingsduringsubsequent
storageinicecomparedwiththoseshowninthechart.
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FreshnessMeterUserManualPage17
Theextentoftheeffectvarieswithfatcontentandtemperatureduringstoragebeforeicing.For
example,leanfishheldfor8hoursatatemperatureofabout5°Cbeforeicingwillgenerallyshowmeter
readingsaboutoneunitlowerthantheappropriateorganolepticchartwouldsuggest.Withfattyfish
theeffectcanbeuptotwiceasgreatforthesametimeandtemperaturebeforeicing.Thereis
evidencetoshowthatthehigherinitialtemperaturescaneasilydoublethiseffect.
Mackerelgenerallybehaveinmuchthesamewayasdoherring,althoughdetailedinformationisnotat
presentavailable.Theorganolepticchartsformackerel(pages41and42)givesomeideaofreadingsto
beexpectedfromcarefullyhandledfish,boxedandiced.
Althoughlessisknownoftherelationshipbetweenobjectivesensoryscoresandmeterreadingsthan
forwhitefish,itisbelievedthatmeterreadingsgiveafairindicationoftheintrinsicqualityof
unhandled,boxedfattyfish,irrespectiveoffatcontent.
Thechartsonpages46to51showrelationshipsbetweentheFishFreshnessMeterreadingsandtimeof
storageiniceforafewspeciesofAfricanfish.ThedatahasbeensuppliedbytheTropicalProducts
Institute,London.
Effectsofhandlingandprocessing
TheFishFreshnessMetermeasurescertainpropertiesoffishmuscleandskinthatchangeina
systematicwayduringstorageinthewetstate.Anyotherprocessthataffectsthestructureofthe
muscleatthecellularlevelwillalsoaffectthemeasurements,almostinvariablytolowerthem.Handling
isanimportantfactor.
AcommonmethodofhandlingfishinEuropeistostoreit,mixedwithice,inbulkaboardthevessel,
thenunloaditontothequaysideandsortthefishintocontainers.Thepressureitissubjectedtointhe
hold,thehandlingduringdischarge,andthesortingprocesstendtolowerthemeterreadingswhen
comparedwithfishthathavebeenstowedcarefullyinboxeswithiceandkeptundisturbeduntil
measured.Thedifferenceisindicatedinthechartsinthe‘Organolepticcharts’section.
Themetercanalsobeusedtogradefillets.Forskin‐onfilletsmakethemeasurementsontheskinside
intheusualway.
Themetermeasurespropertiesofbothskinandmuscle,butitcanstillbeusedwithskin‐offfillets.In
thiscasethemetershouldbeappliedtothebonesideofthefillet.Thereadingsthough,aremuch
lowerthanforwholefishorskin‐onfilletsofequivalentfreshness.Alsodiscriminationinfishmaterial
withafreshnessscorebelow6isnotpossible.Typicalvaluesforcodareshowninthechartsbeginning
onpage23.
Thequalityofherringandmackerelismostsensitivetohandling,andineachcasethisisreflectedby
thereadingsobtainedwiththemeter.Evencarefulhandlingofthefishcanlowertheinstrument
readingsby1or2units.Normalcommercialhandlingreducesthereadingsstillfurther.
Effectsoffreezingandbrining
Freezinghasadrasticeffectonthecellularconstituentsofmuscle.Itisnotpossibletodeterminethe
originalfreshnessofthawedfishsincemeterreadingsareinvariablyintherangeof0–3,whateverthe
qualitybeforefreezing.Infact,thispropertycanbeusedinmanycasestodeterminewhetherfishhas
beenfrozenatsometimeinitshistory.Ifthesample,judgingbyodour,appearanceandflavour
appearstobefreshi.e.shouldhaveahighmeterscore,butinfactgivesalowreadingthenthereare
groundsforsuspectingithasbeenfrozenatsometime.Onceagainjudgmentshouldnotbebasedon
onefishonly;severalfishshouldbeexamined.
Briningalsolowersthereadingthoughnotquiteasmuchasfreezing.Itisthereforenotpossibleto
checkthefreshnessofbrinedfish.
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FreshnessMeterUserManualPage18
Metercareandservice
Cleaningandgeneralcare
TheFreshnessMeterisasealedunitandiswaterproofedpriortoleavingthefactory.However,wedo
notrecommendthattheunitbeimmersedinwateroranyotherfluid.Anyonetamperingwiththeunit,
openingtheseals,etc.,willimmediatelyinvalidatethewarranty.
ThemeterisencasedinimpactresistantABSplastic,withthesensingprobesmadefromstainlesssteel
andcarbonmaterials.Itmaybecleanedwithadampcloth,usingamildsolutionofsoapordetergentin
water.Beawarethatsomehouseholdcleanersmaycontainchemicalswhichcouldseriouslydamage
theplastichousing.Avoidtheuseofanypetroleumbasedsolventcleaners.Donotletslimedryouton
theelectrodesurfaces.Donotattempttocleantheelectrodesurfaceswithabrasives.
Theunitshouldbechargedregularlyandthemeterretainedwithinitscasewhennotinuse,for
safekeeping.
TheFreshnessMeterisaprecisioninstrument.Ensurethattheunitisstoredsecurelyintransit.Donot
droporotherwisemisusetheequipment,asthismayinvalidatethewarranty.
Beforecallingforservice
Ifyouhavereasontobelievethatafaulthasoccurred,pleasefirstofallcheckthefollowing:
•Istheunitswitchedon?
•Hasthebatterypackbeencharged?
IfnoobviousfaultisapparentpleasetelephoneourHelpDeskforadviceandtoreportthefault.
Warrantyandservice
YourTorrymeterisfullywarrantedagainstmanufacturingdefectforaperiodof12months.The
warrantyandterms&conditionsareexplainedinourTechnicalManual,availableontheCD‐ROMor
fromtheDistellwebsite.
Ifyouneedtoreturntheunitforrepair,pleasecontactyoursupplierforadviceonhowtodoso.The
metershouldbecarefullypacked,togetherwithanexplanatorynoteastothenatureofthefault.
ShouldyouhavedifficultyinreturningyourFreshnessMetertoyoursupplierforservicing,youcan
alwayscontactDistelldirectlyusingtheinformationinthe‘ContactDetails’section.Pleasequotethe
dateofpurchaseandgiveafulldescriptionofthefault.
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FreshnessMeterUserManualPage19
DataManagementSystem
Installation
Requirements
TheDataManagementSystem,referredtoasthe‘DMS’,requiresaPCrunningWindowsXPorlaterand
afreeUSBsocketfordatadownloads.
InstallingtheDMS
Thissectiontellsyouhowtoinstalltheprogramonyoursystemandhowtoruntheprogram.
Itisbesttocloseallprogramsbeforeinstallingthesoftware.Youshouldhaveatleast5Mbofharddisk
spaceavailablefortheinstallation.
•InserttheCDinthecomputer;
•Findthe‘Installationfiles’folderontheCDthenopenthe‘DataManagementSoftware
(DMS)’folder;
•RuntheDMSInstaller.exefileandfollowthepromptstocompletetheinstallation
RunningtheDMS
ClicktheWindowsStartbuttononyourdesktop,selectprograms,selectDistellthenlocatetheDMS
iconfromthefileslistedthere.
Youcanusetheprogramstraightawayafterinstallation.Theprogramenablesyoutodownload,print,
save,andexportdata,quicklyandefficiently.TheDMSalsoallowsyoutocreateanduploadyourown
customcalibrationstotheFreshnessMeter(seetheTechnicalManualontheCD‐ROMandontheDistell
website).Allprogramfunctionsareaccessedusingthemenuandtoolbaroptions.Thereisa
comprehensiveon‐linehelpfacility,whichisavailablebyclickingontheHelpmenuoption.
HistoricalDataDownload
ThisfunctionenablesyoutodownloadreadingsthatarestoredintheFreshnessMeter.
Thedataincludesthedateandtimeofthesample,thecalibrationsettingthatwasused,thenumber
andvaluesoftheindividualsamplestaken,andtheaveragevalueofthesamples.
Toillustratetheprocedure,we'llassumethatyouhavetakensomesamplereadingswiththeFreshness
MeterandarereadytodownloadthemtoyourPC.
Step1:ConnectingtheMeter
ConnectthemetertoaUSBportonyourPC,usingthedatacablesuppliedwiththemeter,thenturnthe
meteron.WhenthecableisconnectedtheUSBdriversoftwareinstalledonthePCwillcreatetwo
‘virtualserialports’.NormallytheseareCOM3andCOM4,butthismaychangeifyouhaveotherUSB
virtualserialdevicesinstalled.YourcomputerwillnormallyreserveCOM1andCOM2forbuilt‐in
hardware,orforlegacypurposes
Step2:ConfiguretheDMS
StarttheDMSthenusethePreferencesoptionundertheEditmenutoselecttheCOMporttouse.If
theUSBdrivercreatedCOM3andCOM4thenyouwouldchooseCOM4here.Ingeneralyoushould
alwaysselectthevirtualCOMportwiththehighernumber.Ifyouseeanerrormessagewhenyou
selecttheCOMportthenensurethatthemeterisconnectedproperlyandturnedon.Ifitis,try
selectingadifferentCOMport.
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FreshnessMeterUserManualPage20
Onceyouhaveconnectedthemeterandselectedthecorrectcommunicationport,selectDownload
HistoricalDatafromtheDownloadmenu.TheDMSwillnowmonitortheCOMportforincomingdata
fromthemeter.
Step3:Initiatethedownloadfromthemeter
OncetheDMSisreadyandwaitingfordata,themeterneedstobetoldtobeginthedownload.
Findthe‘Download’optioninthechoicesmenu(see‘MenuStructure’).Atthe‘StandardD/L’option,
presstheRead/YesbuttonthenlookforthedataarrivingattheDMS.
IfnodataisseenattheDMSthenyoumayhaveselectedthewrongCOMport.Gobacktostep2and
tryanalternativeport.
Oncethedatahasbeensafelydownloadedthenyoucan,ifyouwish,erasethedatafromthemeter.
Youcan,alternatively,allowdatatobuildupinthemeteruptothemaximum1000readings.Ifyou
wishtoclearthedatafromthemeteratalaterstagethenyoucangothroughthedownloadprocess
butwithoutconnectingthemetertothePC,thenreplyYestothe‘Erase?’question.
Whenthedatahasbeensuccessfullydownloaded,itwillappearintheDMSinaspreadsheet/grid
form.WiththedataintheDMSyoucannow:
•Printthedata
•Addextracolumnsofinformation
•Savethedatainnativeformasan.FMDfile.
•ExportthedataasaCommaSeparatedValue(.CSV)fileforexportingintootherapplications
suchasExcel,Access,etc.
RealTimeDataDownload
Youcanusethisfunctiontodownloaddatainrealtime,samplebysample,eachtimethatanaverage
readingiscreatedbythemeter.Therealtimedatawillappearonscreenlinebylineasyouusethe
meter.
CHOICES MENU
Y DOWNLOAD N
NoDataStandardD/L
Downloading
Download
Complete
Erase?
YN
IfYesthendataiserased
fromthemeter‘smemor
y
IfNothendataisretained
inthemeter‘smemor
y
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