Instruction Manual CON 510. Bench Conductivity/TDS Meter. 68X Rev 2 01/04. Technology Made Easy...

Transcription

1 Instructin Manual ON 510 Bench nductivity/tds Meter Technlgy Made Easy 68X Rev 2 01/04

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3 Preface This manual serves t explain the use f the ON 510 bench meter It functins in tw ways, firstly as a step by step guide t help yu t perate the meter Secndly, it serves as a handy reference guide It is written t cver as many anticipated applicatins f the meter as pssible If there are dubts in the use f the meter, please d nt hesitate t cntact the nearest Authrized Distributr Eutech Instruments/ Oaktn Instruments cannt accept any respnsibility fr damage r malfunctin t the meter caused by imprper use f the instrument The infrmatin presented in this manual is subject t change withut ntice as imprvements are made, and des nt represent a cmmitment n the part f Eutech Instruments Pte Ltd/ Oaktn Instruments Nte: Eutech Instruments Pte Ltd/ Oaktn Instruments reserves the right t make imprvements in design, cnstructin, and appearance f ur prducts withut ntice pyright 2002 All rights reserved Eutech Instruments Pte Ltd Oaktn Instruments Rev 2 01/04

4 TABLE OF ONTENTS 1 INTRODUTION 1 2 DISPLAY AND KEYPAD FUNTIONS 1 21 Display 1 22 Keypad 2 3 PREPARATION 3 31 nductivity Electrde Infrmatin 3 32 nnecting the prbe t the meter 3 33 nnecting the A/D Adapter 3 34 nnecting the Electrde Hlder 4 4 IBRATION 5 41 Imprtant Infrmatin n Meter alibratin 5 42 Preparing the Meter fr alibratin 6 43 alibratin with nductivity Standards and TDS factr 6 44 alibratin fr TDS Standards Directly 6 45 Selectin f Autmatic r Manual alibratin 6 46 Autmatic alibratin 7 47 Manual alibratin 8 48 Temperature alibratin 9 5 UREMENT Autmatic Temperature mpensatin Manual Temperature mpensatin Taking Measurements Using Manual Ranging Functin HOLD Functin 12 6 MEMORY AND DATA INPUT FUNTIONS Memry Input Memry Recall 13 7 FUNTIONS Mde Overview P10: Viewing alibratin Data P20: Viewing Electrde Diagnsis P30: Meter nfiguratin P40: Temperature P50 Mde f calibratin P60 Selecting the cell cnstant P70: Resetting t factry default settings 22 8 PROBE ARE AND MAINTENANE 23 9 TROUBLE SHOOTING GUIDE ERROR MESSAGES SPEIFIATIONS AESSORIES ADDENDUM 1: IBRATION TIPS ADDENDUM 2: ULATING TDS ONVERSION FATORS ADDENDUM 3: ULATING TEMPERATURE OEFFIIENTS ADDENDUM 4: METER FATORY DEFAULT SETTINGS WARRANTY RETURN OF ITEMS 30

5 1 INTRODUTION Thank yu fr selecting the ON510 bench meter This meter is a micrprcessr-based instrument that is designed t ffer advanced yet user-friendly features fr discerning users - ideal fr labratry and plant applicatins It measures nductivity, Ttal Disslved Slids (TDS) and temperature ( / F) It incrprates large memry capacity f up t 50 data sets and user-custmisable functins all are accessible thrugh the membrane tactile keypad A pull-ut reference card (cncealed at bttm f meter) prvides a quick handy guide t the functins f the individual keys as well as useful trubleshting hints fr yur reference The meter is packaged with a 2-ring Stainless Steel Ultem-bdy nductivity/tds electrde (cell cnstant K = 10) with built-in temperature sensr (Order de: E-ONSEN91W/ ) and an integral electrde hlder Fr the list f accessries refer t the Sectin 12 n Accessries Please read this manual thrughly befre perating yur meter 2 DISPLAY AND KEYPAD FUNTIONS 21 Display The LD (Liquid rystal Display) has an upper and lwer display The upper display shws the measured cnductivity r TDS reading The lwer display shws the measured temperature The display als shws errr messages, keypad functins and prgram functins Upper Display MEM READY HOLD K = ON OFF ERR ms µs ppt ppm O O F AT Lwer Display 9 1 SETup mde indicatr 7 parts per thusand indicatr (ppt) 13 alibratin slutin indicatr 2 urement mde indicatr 8 parts per millin indicatr (ppm) 14 ell cnstant indicatr 3 ibratin indicatr 9 Autmatic Temperature mpensatin 15 ON / OFF indicatr indicatr 4 MEMry mde indicatr 10 Temperature scale indicatr ( F) 16 HOLD indicatr 5 millisiemens indicatr (ms) 11 ERRr indicatr 17 READY indicatr 6 micrsiemens indicatr (µs) 12 Prbe indicatr 1

6 22 Keypad The splash-prf membrane tactile keypad allws easy key entry Each buttn, when pressed, has a crrespnding graphic icn r indicatr displayed n LD Sme buttns have several functins depending n its mde f peratin Key ON/OFF HOLD MODE / / MI & MR / Functin Pwers n and shuts ff the meter When yu switch n the meter, the meter starts up in the mde that yu last switched ff frm Fr example, if yu shut the meter ff in TDS measurement mde, the meter will be in TDS measurement mde when yu switch the meter n Freezes the measured reading T activate, press HOLD while in measurement mde T release, press HOLD again Selects the measurement parameter Tggles between cnductivity and TDS Tggles between alibratin and Measurement mde NOTE: Temperature calibratin is available frm cnductivity/tds calibratin mde functin: Press t cnfirm values in alibratin mde and t cnfirm selectins in mde functin: Press t enter manual ranging functin The indicatr blinks while in manual ranging functin In Measurement mde: Press MI (memry input) t stre values with its crrespnding temperature values in the memry Press MR (memry recall) t retrieve data frm memry (Last-In-First-Out Sequence) In alibratin mde: Press t scrll thrugh calibratin values In mde: Press t scrll thrugh the setup subgrup prgram Takes yu int the mde This mde lets yu custmize meter preference and defaults, and view calibratin data and select cell cnstant 2

7 3 PREPARATION 31 nductivity Electrde Infrmatin The ON510 bench meter is supplied with a nductivity/tds electrde (with a sturdy lcking 6-pin cnnectr) This nductivity/tds electrde (de N: EONSEN91W/ ) cmes with Stainless Steel rings, cell cnstant f K = 10, and a built-in temperature sensr fr Autmatic Temperature mpensatin (AT) Its specially designed Ultem-bdy husing has gd chemicalresistant prperties It prvides fast temperature respnse and reduces air bubble entrapment, which makes it easy t btain accurate, stable readings The prbe materials used which have gd chemical durability include: 1 Plyetherimide (Ultem) prtective prbe guard 2 Plybutylterphalate (Valx) sensr husing 3 Stainless Steel (SS 304) 2 steel bands Prper use f prbe is essential t ensure that the ptimum measurement is taken in a shrt time The remvable prtective plastic prbe guard is meant fr simple peridic maintenance and it must be kept in tact during measurement and calibratin Always immerse the prbe beynd upper steel band NOTE: DO NOT remve the prtective prbe guard during measurement and calibratin as it may affect yur readings NOTE: We recmmend that yu d nt submerge the prbe abve the prtective prbe guard Yu can submerge the cable fr brief perids f time, but nt cntinuusly See Sectin 8 fr Prbe are and Maintenance infrmatin 32 nnecting the Prbe t the Meter 1 Align the ntch and 6 pins n the meter with the hles in the 6-pin cnnectr Push dwn and turn the lcking ring clckwise t lck int place 2 T remve prbe, turn the lcking ring cunterclckwise n prbe cnnectr until it is free Pull prbe gently away frm the meter AUTION: DO NOT pull n the prbe crd r the prbe wires might discnnect NOTE: Keep cnnectrs clean D nt tuch cnnectr with siled hands 33 nnecting the A/D Adapter Slide the A/D adapter jack int the scket marked D f the meter until it is firmly seated Ensure that the pwer t the A/D adapter is switched ff Fr A/D adapter always ensure that main vltage matches that f the adapter A/D adapters used shuld have the fllwing specificatins r settings Output: - Vltage: 9 VD urrent: 500 ma NOTE: Ensure that the input main vltage (110/220 V) matches yur adapter requirements befre cnnectin 3

8 34 nnecting the Electrde Hlder The integral electrde hlder serves as a handy hlder fr a few electrdes r a separate temperature prbe during measurement r when nt in use This bench meter s base plate has a side metal bar t which yu can attach an integral swivel electrde hlder Yu can munt the electrde hlder n either right r left side f the meter T psitin the electrde arm: Use a Phillips screwdriver t remve the screw hlding the electrde hlder Slide the side metal bar until the secnd screw slt lines up with the riginal screw hle Use the screw remved earlier t secure the electrde hlder int psitin Nte the side metal bar is reversible If desired, remve screw hlding electrde hlder base and slide ut f brackets, slide base int brackets n ppsite side, and tighten screw Bdy f Electrde Hlder T install the electrde arm t the meter: T munt the electrde arm int the metal rd n the side bar, align the slt with the metal rd and base f electrde arm Push it dwnwards until it fully sits int psitin Avid using excessive frce when fixing r remving The electrde arm is ready fr use Side Metal Bar Base f Electrde Hlder NOTE: Mve the base f the electrde hlder if yu wish t swing the electrde hlder T prevent the meter frm tppling ver causing accidental spills, DO NOT swing the bdy f the electrde hlder 4

9 4 IBRATION 41 Imprtant Infrmatin n Meter alibratin The ON 510 bench meter allws yu t perfrm autmatic calibratin (nly fr nductivity mde) r manual calibratin (applicable t bth nductivity/tds mde) The meter can calibrate either single pint r multi-pint up t 5 calibratin pints (manual mde) with a maximum f 1 pint in each measurement range Use single-pint autmatic calibratin when calibrating using nductivity standard calibratin slutins (as mentined in Sectin 46) as it suffices When calibrating using uncmmn r nn-standard nductivity/tds calibratin slutins which are freshly prepared, use the manual calibratin ptin as it allws yu t manually set t the desired value t match the standards being used Hwever if yu are measuring sample values in mre than ne range, it is recmmended t calibrate each f the ranges which yu are measuring t ensure best meter accuracy If yu are measuring in ranges near t r greater than 20 ms (10 ppt if TDS factr is set t 05), r near t r lwer than 100 µs (50 ppm), calibrate the meter at least nce a week t get specified ±1% Full Scale accuracy If yu are measuring in the mid-ranges and yu washed the prbe in de-inized water and stred it dry, calibrate the meter at least nce a mnth If yu take measurements at extreme temperatures, calibrate the meter at least nce a week Fr best results, select a standard value clse t the sample value yu are measuring Alternatively, use a calibratin slutin value that is apprximately 2/3 the Full-Scale value f the measurement range yu plan t use Fr example, in the 0 t 2000 µs/cm cnductivity range, a 1413 µs/cm slutin is a gd slutin fr calibratin The fllwing table lists all the crrespnding cnductivity and TDS ranges Yu shuld calibrate each range using a suitable standards slutin that falls between the values in the recmmended calibratin slutin range clumn Range Indicatr nductivity Range Recmmended alibratin Slutin Range TDS Range Recmmended alibratin Slutin Range r µs/cm µs/cm ppm ppm r µs/cm µs/cm ppm ppm r µs/cm µs/cm ppm ppm r ms/cm ms/cm ppt ppt r ms/cm ms/cm ppt ppt When yu recalibrate yur meter, ld calibratin values are replaced n that specific measurement range Fr example, if yu previusly calibrated the meter at 1413 µs/cm in the µs/cm range and yu recalibrate at 1500 µs/cm (in the same range f µs/cm), the meter will replace ld calibratin data (1413 µs/cm) in that range if the meter is in the multi-pint calibratin mde and the meter will retain all calibratin data in ther ranges Or else, the calibratin data replaces with new data fr all ranges (in single-pint calibratin mde) T view calibrated slutins and its crrespnding cell cnstants at respective range, see main-menus P10 and P20 T cmpletely recalibrate yur meter, r when yu use a replacement prbe, it is best t clear all the calibratin data in the meter s memry T erase all the ld cnductivity and TDS calibratin data cmpletely frm memry, see main-menu P70 Temperature efficient: This meter is factry set t a temperature cefficient f 21 % per Fr mst applicatins this will prvide gd results See sub-menu P41 t set the temperature cefficient t different value See als Addendum 2, alculating Temperature efficients t determine the apprpriate temperature cefficient fr yur slutin 5

10 Nrmalizatin Temperature: The factry default value fr nrmalizatin temperature is 25 If yu need t nrmalize t a value ther than 25, see sub-menu P42 42 Preparing the Meter fr alibratin Befre starting calibratin, make sure yu are in the crrect measurement mde Otherwise press MODE key t tggle between measurement mdes When yu switch n the meter, it starts up in the last unit f measure when yu last shut ff the meter DO NOT reuse calibratin slutins after each calibratin has been perfrmed ntaminants in the slutin can affect the calibratin, and eventually the accuracy f the measurements Use fresh calibratin slutin each time yu calibrate yur meter Always remember t rinse thrughly with de-inized water r a rinse slutin after each calibratin t prevent any carry-ver NOTE: When entering calibratin mde, the meter will display the uncalibrated value T abrt r exit frm any calibratin mde r ptins withut cnfirming any set values, DO NOT press the key Press / instead This will retain the meter s ld calibratin data in the specific measurement range r previus ptins 43 alibratin with nductivity Standards and TDS factr The cncentratin f salts disslved in slutin increases the cnductivity f that slutin This relatinship varies frm salt t salt and is rughly linear ver a given range fr a given salt The TDS cnversin factr is the number used by the meter t cnvert frm cnductivity t TDS Default is 050; allwed windw is 040 t 100 Instead f calibrating fr TDS directly, yu can calibrate the ON 510 bench meter by: 1 calibrating t cnductivity standards and then 2 entering the apprpriate TDS cnversin factr int the meter T determine the cnductivity t TDS cnversin factr fr yur slutin: Addendum 2 lists sme cmmnly used cnversin factrs Addendum 3 describes hw t calculate the TDS cnversin factr fr ther slutins Enter the TDS cnversin factr int yur meter as described under sub-menu P34 44 alibratin fr TDS Standards Directly The factry default setting fr TDS cnversin factr is 050 If yur slutin has a different TDS factr, yu can imprve the calibratin accuracy by setting the crrect TDS factr (040 t 100) prir t calibratin in sub-menu P34 45 Selectin f Autmatic r Manual alibratin This meter is capable f perfrming either autmatic fr nductivity measurement mde r manual calibratin methd fr bth nductivity and TDS measurement mdes In the autmatic calibratin mde, the meter autmatically detects and verifies the apprpriate knwn calibratin standards slutins being calibrated befre accepting these particular calibratin standards as ne f its calibratin values in a specific measurement range This autmatic calibratin mde frees yu frm cumbersme calibratin prcedure While in the manual calibratin, nn-standards calibratin values can be used fr calibratin, in which yu can manually input the apprpriate values as yur desired calibratin standards in each specific range Prceed t main-menu P50 t select the type f calibratin methd befre perfrming calibratin 6

11 46 Autmatic alibratin (Only fr nductivity) In the autmatic calibratin mde, the ON 510 bench meter is capable f accepting either single-pint r up t 4 pints fr multi-pint calibratin with maximum f 1 pint per specific measurement range using knwn calibratin standards values which include: 84 µs/cm ( µs/cm), 1413 µs/cm ( µs/cm), 1288 ms/cm ( ms/cm) and 1118 ms/cm ( ms/cm) NOTE: Yu need t set yur desired ptin ie number f calibratin pints in the main-menu P50 befre perfrming calibratin 461 nductivity Autmatic alibratin 1 If necessary, press the MODE key t select cnductivity mde 2 Rinse the prbe thrughly with de-inized water r a rinse slutin, then rinse with a small amunt f calibratin standard 3 Dip the prbe int the calibratin standard Immerse the prbe tip beynd the upper steel band Stir the prbe gently t create a hmgeneus sample Allw time fr the reading t stabilize 4 Press / t enter cnductivity calibratin mde The [] indicatr will appear in the upper right crner f the display 5 The lwer display will scan and lck the clsest set calibratin values mmentarily Pressing befre the set displayed value being lcked will be prmpted by an errr message and remain in the calibratin mde 6 Wait fr [READY] indicatr t appear befre pressing key t cnfirm calibratin value The upper display will shw done nce the calibratin is successfully perfrmed The meter returns t the [] measurement mde 7 T abrt calibratin withut cnfirming, press / t revert back t measurement mde N calibratin is perfrmed at this stage 8 T perfrm the next pint calibratin in the multi-pint calibratin, repeat step 1-7 again until all pints have been calibrated if necessary MODE READY READY us AT us READY us AT 7

12 47 Manual alibratin (nductivity/tds) The meter accepts either single pint r multi-pint (up t 5 pints) manual calibratin with maximum f 1 pint per measurement range Freshly prepare yur standards slutin befre calibratin Refer t the table in Sectin 41 fr mre details f the recmmended standards calibratin range MODE READY us Yu can ffset r manually adjust the nductivity r TDS reading up t ±40% frm its default setting If yur measured value differs by mre than ±40%, clean r replace prbe as needed Refer t Sectin 8 fr Prbe Maintenance AT NOTE: Yu need t set yur desired ptin ie number f calibratin pints in the main-menu P50 befre perfrming calibratin us 471 nductivity Manual alibratin 1 If necessary, press the MODE key t select cnductivity mde 2 Rinse the prbe thrughly with de-inized water r a rinse slutin, and rinse with a small amunt f calibratin standard 3 Dip the prbe int the calibratin standard Immerse the prbe tip beynd the upper steel band Stir the prbe gently t create a hmgeneus sample Allw time fr the reading t stabilize 4 Press / key t enter cnductivity calibratin mde The [] indicatr will appear in the upper right crner f the display 5 Use MI/ r MR/ key t adjust the value n the upper display t match the value f the calibratin standards 6 Press t cnfirm calibratin value The meter returns t the [] measurement mde 7 T abrt calibratin withut cnfirming, press / key t revert back t measurement mde N calibratin is perfrmed at this stage 9 Fr single-pint calibratin the meter autmatically reverts back t the measurement mde 10 Fr multi-pint calibratin repeat steps 2 t 6 fr the secnd t fifth calibratin value in specific measuring ranges T abrt calibratin at any calibratin pints, press / nce and the meter reverts t measurement mde READY us us AT 472 TDS Manual alibratin The calibratin sequence is exactly the same as nductivity manual calibratin Ensure that yu set the crrect TDS factr befre calibratin Refer t Sectin 74 fr details 8

13 48 Temperature alibratin The nductivity electrde (E-ONSEN91W/ ) has a built-in temperature sensr fr AT The temperature sensr is factry calibrated t the meter alibrate yur sensr nly if yu suspect temperature errrs that may have ccurred ver a lng perid f time r if yu have a replacement prbe Temperature alibratin 1 Make sure the electrde is attached t the 6-pin cnnectr 2 Pwer the meter n The [AT] indicatr will appear at the right-hand side f the LD t indicate that the temperature sensr is in gd wrking cnditin If the AT indicatr des nt light up, see sub-menu P33 t switch it n 3 Press MODE key t select either cnductivity r TDS mde 4 Press / t enter either nductivity r TDS calibratin mde The [] indicatr appears abve the upper display 5 While yu are in the nductivity r TDS calibratin mde, press MODE t enter int Temperature calibratin mde The upper display shws current temperature reading and the lwer display shws the factry default temperature value 6 Dip the electrde int a slutin f knwn temperature (ie a cnstant temperature bath) Allw abut 3 t 5 minutes fr the built-in temperature sensr t stabilize its measured reading 7 Adjust using the MI/ r MR/ key t set t the crrect temperature value (ie the temperature f the cnstant temperature bath) in increments f 01 Maximum allwable ffset temperature value is 50 8 Once yu have selected the crrect temperature, press key T abrt r exit this calibratin mde withut cnfirming the temperature calibratin value, DO NOT press key Press / key instead and the meter autmatically reverts back t the measurement mde MODE MODE us AT AT READY us AT 9

14 5 UREMENT The ON 510 bench meter measures up t 5 different measurement ranges with aut-ranging capability which autmatically detects and prmptly switches t the apprpriate range The meter als allws measurements t be taken with autmatic r manual temperature cmpensatin The factry default is AT n AT basically cmpensates fr any temperature variances f measured sample slutin temperature autmatically frm the nrmalizatin temperature set Default nrmalizatin temperature is 250 (770 F) Hwever if yu need t adjust the default value frm 150 t 300, yu may access sub-menu P34 first befre measurement 51 Autmatic Temperature mpensatin Fr autmatic temperature cmpensatin (AT) simply plug the cnductivity/tds prbe int the meter The [AT] indicatr will light n the LD Default is AT YES NOTE: If the AT indicatr des nt light up, manual temperature cmpensatin may be set in the sub-menu P33 See sub-menu P33 fr directins n selecting AT r MT T select ptin either AT YES r no, use either MI/ r MR/ key Press t cnfirm Otherwise press / key t abrt ptin selectin AT AT OR 10

15 52 Manual Temperature mpensatin NOTE: Fr manual temperature cmpensatin, yu must deactivate the AT mde t no as shwn in submenu P Setting a manual temperature cmpensatin value T set manual temperature cmpensatin value, yu need t determine and enter the desired temperature value int the meter This value is based n which reading will be manually temperature cmpensated Yu may select any temperature between 0 and 100 (32 t 212 F) Default value is Switch the meter n if necessary Press MODE t select any measurement mde 2 If necessary, select AT t OFF as described in Sectin 51 Nte the [AT] indicatr shuld nt appear n the display 3 Press / t enter int either cnductivity r TDS calibratin mde The [] indicatr will appear abve the upper display 4 While in nductivity r TDS calibratin mde, press MODE key t enter int temperature calibratin mde The upper display shws the current temperature setting and the lwer display shws the default value 250 (770 F) r its last set temperature value 5 heck the temperature f yur sample slutin using an accurate thermmeter 6 Use MI/ r MR/ key t ffset and match the temperature t the measured value f the sample slutin 7 Press key t cnfirm the set temperature value and the meter returns t the cnductivity r TDS measurement mde MODE MODE AT AT The meter will nw display yur newly set temperature value in the lwer display and will cmpensate nductivity r TDS readings accrdingly based n this set temperature NOTE: T exit this prgram withut cnfirming the manual temperature cmpensatin value, DO NOT press key in step 7 Press / key instead and nte that n change is being made at this stage READY us 53 Taking Measurements T take readings: 1 Always rinse the prbe with de-inized r distilled water befre use and after each sample t remve any impurities adhering t the prbe bdy Shake r air dry T avid cntaminatin r dilutin f yur sample, rinse prbe with a small vlume f yur sample slutin 2 Press ON t switch n the meter and the [] indicatr appears n the tp f the LD 3 Dip the prbe int the sample Ensure that the slutin level is abve its upper steel band Stir the prbe gently in the sample t create a hmgenus sample 4 Allw time fr the reading t stabilize Nte the reading n the display 5 Press MODE t tggle between nductivity and TDS measurement Taking measurements with READY indicatr selected n If the READY indicatr has been activated, the [READY] indicatr lights whenever the reading has stabilized Yu may switch the READY indicatr n r ff by fllwing the sequence as described in sub-menu P31 Taking measurements with the Aut-Hld feature selected n When a reading has stabilized fr mre than 5 secnds, the Aut-Hld feature autmatically freezes the displayed reading and the [HOLD] indicatr appears Press HOLD nce t release the reading Yu may deactivate the Aut-Hld feature as described in sub-menu P31 11

16 54 Using Manual Ranging Functin Althugh the ON 510 bench meter has an autmatic ranging capability, yu may als manually select any specific measurement range yu wish t wrk n by pressing each time fr every range Range Indicatr nductivity Range TDS Range (if TDS factr is 05) r µs/cm ppm READY us AT r µs/cm ppm r µs/cm ppm r ms/cm ppt r ms/cm ppt us 1 T manually select the desired measuring range, press key while yu are in the measurement mde The first range will appear n the display and the [] indicatr blinks 2 Press key again (if needed) until the desired range is selected 3 T re-select the Aut-ranging functin, repeatedly press key until the [] indicatr appears withut blinking The display will then scrll thrugh the varius ranges and the Aut-ranging functin resumes Or simply pwer ff and n again will restart meter int Aut-ranging functin as default READY AT us AT NOTES: If the value f the slutin yu are measuring is higher than the range selected, an errr message cde Or will appear n the upper display indicating an ver-range cnditin Press key until the crrect range is selected Hwever the meter reverts back t the Aut-ranging functin nce it is pwered ff 55 HOLD Functin HOLD This feature allws yu t freeze the displayed reading mmentarily when activated in the measurement mde and the [HOLD] indicatr appears n the LD T release the held value, press HOLD again and the [HOLD] indicatr disappears Yu may cntinue t take measurements READY HOLD us AT 12

17 6 MEMORY AND DATA INPUT FUNTIONS 61 Memry Input The meter s nn-vlatile memry can stre and recall up t 50 data sets which include nductivity and temperature r TDS and temperature Data sets are retained even if the pwer is shut ff unless these stred data sets are being verwritten by new nes T stre a reading: 1 During any measurement mde press MI/ key t input any data int the memry 2 MEM, St and memry lcatin number will be displayed t indicate that the readings are being stred int meter s memry at that specific lcatin number The meter then returns t the measurement mde 3 T cntinue string data sets, press MI/ t input subsequent data int memry READY MEM us AT NOTE: If the memry is full, the first data set value stred will be verwritten t create space fr the new value Data sets are stred sequentially in the next unccupied memry lcatin and cannt be selectively input int specific memry lcatin t be stred 62 Memry Recall Yu can access memry recall frm any measurement mde nly This functin recalls and displays previus readings being stred in the meter s memry in Last-In-First-Out" sequence Fr example the mst recent reading stred in lcatin 20 will be displayed first when memry recall is activated T selectively view any specific memry lcatin, use MI/ r MR/ t select and press t view the crrespnding data set value stred in that memry lcatin MEM T recall readings: 1 Press MR/ key nce t retrieve the last reading stred The memry lcatin screen MEM, Lc and the memry number will flash n the display 2 Press t recall the reading stred under that memry number 3 T view the next memry lcatin, press key nce and the display autmatically mves t the next memry lcatin 4 Press / key t revert back t measurement mde if yu d nt wish t access memry recall further 5 If necessary, press MI/ r MR/ key t select any specific memry lcatin Press key t view the stred values in that memry lcatin If there is n data stred in particular memry lcatin, bth upper and lwer displays will shw ---- MEM MEM us AT MEM 13

18 7 FUNTIONS The setup mde allws yu t custmize the meter s setting t yur individual preferences The ON510 meter features different main prgram menus and sub-menus which rganize individual parameters like a matrix-frmat Details f each main prgram menu: 1 P10: Viewing previus calibratin data - all calibrated slutins fr each range 2 P20: Viewing electrde diagnsis - effective cell cnstants fr each range 3 P30: Meter cnfiguratin Ready, Aut-Hld, Temperature unit f measure, AT r MT, TDS Factr 4 P40: Setting f Temperature efficient, Nrmalizatin Temperature 5 P50: Setting f Autmatic r Manual and Single r Multi-pint calibratin 6 P60: Setting f cell cnstant 7 P70: Resetting meter t factry defaults 71 Mde Overview Press t enter int the setup mde with [] indicatr n the tp left f LD display Use the MI/ and MR/ keys t scrll up and dwn respectively thrugh main menus At each main menu, press t enter int a particular sub-menu t make specific changes frm the meter s default settings See Addendum 4 fr a table f meter factry default settings P10: Viewing Previus alibratin Data P11 First range calibratin slutin P12 Secnd range calibratin slutin P13 Third range calibratin slutin P14 Furth range calibratin slutin P15 Fifth range calibratin slutin P20: Viewing alibrated ell nstants P21 Effective cell cnstant fr first range P22 Effective cell cnstant fr secnd range P23 Effective cell cnstant fr third range P24 Effective cell cnstant fr furth range P25 Effective cell cnstant fr fifth range P30: Meter nfiguratin P31 READY indicatr On/Off and Aut-Hld On P32 Select r F P33 Select Autmatic r Manual Temperature mpensatin P34 Setting TDS cnversin factr (available in TDS mde) P40: Temperature P41 Adjusting temperature cefficient P42 Adjusting nrmalizatin temperature 14

19 P50: Mde f alibratin Selectin f Autmatic r Manual alibratin (nly in nductivity mde) Selectin f Single r Multi-pint alibratin P60: Selecting cell cnstant Selecting cell cnstant K: 01, 10, 100 P70: Reset t factry defaults Reset meter t factry defaults 72 P10: Viewing alibratin Data This mde lets yu recall previus calibratin data f nductivity/tds This is fr viewing nly and n changes can be made 1 Frm measurement mde, press key t enter int setup [] mde 2 Use MI/ r MR/ t scrll thrugh sub-menus until yu view main-menu P10 n the display 3 Press repeatedly t view all previus calibratin data, starting frm the first range till fifth range The meter will display the calibratin value f that particular range prvided calibratin is perfrmed If any f range is nt being calibrated the upper display shws When yu have scrlled thrugh all calibratin data, yu will autmatically return t the main-menu P10 Press / key if yu wish t return t measurement [] mde Or t exit frm viewing f any range in respective submenus, press / key reverts t the main-menu P10 NOTE: If yu enter int the setup mde frm nductivity measurement mde, calibratin data will be in µs r ms Similarly if yu enter int the setup mde frm TDS measurement mde, calibratin data will be in ppm r ppt us us 15

20 73 P20: Viewing Electrde Diagnsis Main prgram 20 shws the effective cell cnstant fr each range being calibrated The cell cnstant is adjusted accrding t yur calibratin ptins that let yu check the prbe s parameters fr diagnstic purpses 1 Frm measurement mde, press key t enter int setup [] mde 2 Use MI/ r MR/ key t scrll thrugh sub-menus until yu view main-menu ELE P20 n the display 3 Press the key repeatedly t view the effective cell cnstant fr each range 4 When yu have scrlled thrugh all calibratin data, yu will autmatically return t the main-menu P20 Press / key if yu wish t return t measurement [] mde NOTE: ell cnstants f electrde will degrade with time and usage depending n yur maintenance and wear and tear f the electrde being used Yu can use this feature t prmpt yu the need fr a new prbe prir t ttal failure Recmmended value as an indicatr fr a replacement f prbe is either 060 r 140 (±40% f 1000) K= K= 74 P30: Meter nfiguratin P31: READY indicatr and Aut-Hld functin Prgram P31 allws yu t select READY ON, READY OFF and activate the Aut- Hld functin READY indicatr is a useful feature that prmpts yu whenever yur measured reading has stabilized Once activated yu will see [READY] indicatr lights up whenever yur readings have stabilized At this mment, yu may depress MI/ t stre the reading int meter s memry Select READY OFF fr instantaneus measurement with n [READY] indicatr being lighted up n the display Yu may activate the Aut-Hld functin which autmatically freezes measured reading after it has stabilized fr mre than 5 secnds Once the display is frzen, the [HOLD] indicatr appears n the display At this mment, yu may depress MI/ t stre the reading int meter s memry Press HOLD nce t release the held reading and t access ther functins in the measurement mde Yu may deactivate this feature by selecting either READY ON/OFF 1 Frm measurement mde, press key t enter int setup [] mde 2 Use MI/ r MR/ key t scrll thrugh the sub-menus until yu view main-menu P30 n the display 3 Press key t select sub-menu P31 with upper display shwing rdy 4 Use MI/ r MR/ key t select the apprpriate cnfiguratin yu require Selecting ON switches the READY indicatr n; OFF switches the READY indicatr ff; ON and HOLD tgether switches the Aut-Hld feature n 5 Press t cnfirm selectin and t prceed t Prgram P32 If yu d nt wish t cntinue P32, press / t return back t the measurement [] mde READY ON READY OFF READY HOLD ON 16

21 P32 Selecting r F Yu can select between and F as unit f measure fr temperature readings Meter default is 1 Frm measurement mde, press key t enter int Setup [] mde 2 Use MI/ r MR/ key t scrll thrugh the main-menu P30 and press until yu can view sub-menu P32 n the display 3 Use MI/ r MR/ key t tggle between and F 4 Press t cnfirm selectin and yu will autmatically return t the main-menu P30 Press / key if yu wish t return t measurement [] mde NOTE: Similarly if yu are accessing main-menu P30, pressing twice will take yu t this sub-menu P32 F P33 Selecting Autmatic r Manual Temperature mpensatin This Prgram P53 allws yu select between Autmatic Temperature mpensatin (AT) and Manual Temperature mpensatin Meter default is AT 1 Frm measurement mde, press key t enter int setup [] mde 2 Use MI/ r MR/ key t scrll thrugh the main-menus OF P30 and press key repeatedly until yu cme t the sub-menu P33 which the upper display shws AT and P33 n the lwer display 3 Press key again The upper display shws AT and the lwer display shws YES r NO 4 Use MI/ r MR/ key t select the Autmatic Temperature mpensatin n r ff YES = AT n; NO = AT ff 5 Press key t cnfirm selectin and t return t the sub-menu P33 Press / key t return t measurement [] mde AT AT 17

22 P34 Setting the TDS factr (In TDS Mde) The cncentratin f salts disslved in slutin increases the cnductivity f that slutin This relatinship varies frm salt t salt and is rughly linear ver a given range fr a given salt The TDS cnversin factr is the number used by the meter t cnvert frm cnductivity t TDS T determine the cnductivity t TDS cnversin factr fr yur slutin: Addendum 2 lists sme cmmnly used cnversin factrs Addendum 3 describes hw t calculate the apprpriate TDS cnversin factr fr ther slutins Yu can manually set TDS cnversin factr between 040 and 100; meter s default is 050 ppt ppm 1 Frm measurement mde, press key t enter int setup [] mde 2 Use MI/ r MR/ key t scrll thrugh the main-menus OF P30 and press key repeatedly until yu cme t the sub-menu Prgram P34 which the upper display shws tds and P34 n the lwer display 3 Press the key again t make changes t the displayed value The upper display shws a value and the lwer display shws tds 4 Use MI/ r MR/ key t set yur calculated TDS cnversin factr 5 Press the key t cnfirm selectin and t return t the sub-menu P30 Press / key t return t measurement [] mde ppt ppm 75 P40: Temperature P41 Adjusting the Temperature efficient The temperature cefficient is the amunt f change in cnductivity per degree f temperature; it is expressed in percent per r F Entering the exact temperature cefficient f yur slutin lets yu accurately cmpensate temperature fr almst any slutin* Yu can adjust 00 t 100 % per r F Meter default is 21% per r F F 1 Frm measurement mde, press key t enter int setup [] mde 2 Use MI/ r MR/ key t scrll thrugh the main-menu tpr P40 and press until yu can view sub-menu P41 3 Press key t make change t the displayed value The upper display shws the temperature cefficient and the lwer display shws to 4 Press MI/ r MR/ key t set the temperature cefficient f yur slutin 5 Press t cnfirm selectin and t prceed t sub-menu P42 Press / key twice t return t measurement [] mde F NOTE: If yu d nt knw the temperature cefficient f yur slutin yu can determine the crrect value using the frmula in Addendum 3 alculating Temperature efficients 18

23 P42 Adjusting the Nrmalizatin Temperature Yur meter will nrmalize its cnductivity measurements t a standard temperature that yu can select Yu can adjust the nrmalizatin temperature frm 15 t 30 (59 t 86 F) Meter default is 250 (77 F) 1 Frm measurement mde, press t enter int setup [] mde 2 Use MI/ r MR/ key t scrll thrugh the main-menu P40 and press thrice repeatedly until yu can view the sub-menu P42 which the upper display shws tnr n and P42 n the lwer display 3 Press key t make change t the displayed value The upper display shws the nrmalizatin temperature and the lwer display shws tnr 4 Press MI/ r MR/ key t set the nrmalizatin temperature (in the specific unit f temperature which is set at sub-menu P32) 5 Press t cnfirm selectin and t return t the main-menu P40 Press / key t return t measurement [] mde F F 19

24 76 P50 Mde f calibratin The ON 510 bench meter allws yu t perfrm autmatic (nly fr nductivity mde) r manual calibratin (applicable t bth nductivity/tds mde) Similarly yu may chse t perfrm either single-pint r multi-pint calibratin (up t 4 preset calibratin standards in autmatic calibratin mde) Refer t the Sectin 4 fr details n calibratin 1 Frm measurement mde, press t enter int setup [] mde 2 Use MI/ r MR/ key t scrll thrugh main-menu A P50 3 Press key t enter int this main-menu fr selectin f Autmatic alibratin either no (Manual) r YES (Autmatic) using MI/ r MR/ key 4 Once the ptin is selected, press key t cnfirm The next display shws the ptin f Single-pint alibratin (SP) r Multi-pint alibratin 5 Use MI/ r MR/ key t select YES if yu wish t perfrm Single-pint alibratin and no t perfrm Multi-pint alibratin 6 Press key t cnfirm after apprpriate selectin is made and t return t the main-menu P50 Press / key t return t measurement [] mde 20

25 77 P60 Selecting the cell cnstant This prgram allws yu t select the apprpriate cell cnstant f K = 01, 10 r 100 which is suitable fr measurement range being used Use a cell f K = 10 fr mid-range measurements Use a cell f K = 10 fr high range measurements (abve 20 ms r 10 ppt) Use a cell f K = 01 fr lw range measurements (belw 20 µs r 10 ppm) The cell included with yur meter has a cell cnstant f K = 10 1 Frm measurement mde, press key t enter int setup [] mde 2 Use MI/ r MR/ key t scrll thrugh the main-menu ELL P60 and press key t enter int the selectin ptins fr the cell cnstant 3 Use MI/ r MR/ key t select the cell cnstant between K = 10, 01, r 10 4 Press key t cnfirm selectin and t return t the main-menu Press / key t return t measurement [] mde NOTES: When using a cell f K = 01, the lwest measuring range will be 0 t 2000 µs/cm (0 t 1000 ppm), the highest measuring range will be 0 t 2000 ms/cm (0 t 1000 ppt) When using a cell f K = 10, the highest measuring range will be 0 t 2000 ms/cm (0 t 1000 ppt) and the lwest measuring range will be 0 t 2000 µs/cm (0 t 1000 ppm) K= K= K= 21

26 78 P70: Resetting t factry default settings Prgram 70 allws yu t reset all parameters t factry default settings This clears all calibratin data, memry, and any ther setup functins yu might have changed IMPORTANT: Once activated the meter s settings and calibratin data will be erased and always exercise cautin as meter reset is nt reversible 1 Frm measurement mde, press key t enter int setup [] mde 2 Use MI/ r MR/ key t scrll thrugh the main-menu rst P70 and press key t enter int the selectin ptins fr the meter reset 3 Use MI/ r MR/ key t tggle between NO and YES NO retains current settings; YES resets t factry default settings 4 Press key t cnfirm selectin and t return t the measurement mde Otherwise press / key t return t measurement [] mde withut resetting t factry default NOTE: See Addendum 4 fr a table f factry default settings 22

27 8 PROBE ARE AND MAINTENANE Keep the nductivity/tds prbe clean Rinse the prbe twice, and gently swirl it while yu take readings Fr best accuracy, sak a dry prbe fr at least 5 t 10 minutes r lnger befre calibratin Rinse prbe with deinized r tap water befre string Never scratch the bands with a hard substance D nt strike the prbe against any hard surface D nt immerse the prbe in ily slutins lean the electrde thrughly by stirring it in a mild detergent bath r isprpyl alchl Wipe the prbe with a sft tissue paper Rinse thrughly in tap water and then in deinized water Recalibrate the meter after cleaning the prbe The cnductivity prbe (Order Part N E-ONSEN91W/ ) which is included with yur meter features a remvable prbe guard t make cleaning easy T remve prbe guard: 1 Grip yellw prbe guard and twist clckwise The lcking ntch will release 2 Slide prbe guard ff end f prbe 23

28 9 TROUBLE SHOOTING GUIDE Prblem Pssible ause Slutin N display A A utlet nt switched n A Switch n pwer supply B A adapter scket nt inserted prperly B Re-insert A adapter scket Unstable readings A Air bubbles in prbe A Tap prbe t disldge air bubbles B Dirty prbe B lean prbe and recalibrate External nise pickup Mve away frm nise D Brken prbe D Replace prbe Or n upper display A Prbe is shrted A Test prbe B Prbe is in t-high slutin fr measurement range B Use different slutin r select different range Nt able t calibrate A Dirty/Oily prbe A lean B Incrrect prbe cell cnstant B Replace and use crrect prbe 10 ERROR MESSAGES LD Display Indicates Pssible ause Slutin Err annunciatr Unrecgnised key entry Incrrect key entry r selectin & Err annunicatr blink alibratin errr Incrrect value input during calibratin Dirty r faulty prbe Release key heck mde Select apprpriate key heck value lean r replace prbe 24

29 11 SPEIFIATIONS SPEIFIATIONS ON510 nductivity Range 0 t 2000, 2000, 2000 µs/cm; 0 t 2000, 2000 ms/cm TDS Range 0 t 1000, 1000, 1000 ppm; 0 t 1000, 1000, 100 ppt (max 200 ppt depending n factr setting) Reslutin 005 % Full Scale Accuracy ±1% Full Scale Temperature Range 00 t 1000 ; 320 t 212 F Temperature Reslutin / Accuracy ell nstant Temperature mpensatin 01 / ± 05 r ± 09 F 01, 10, 100 (selectable) Autmatic / Manual (frm 0 t 100 ) Temperature efficient 00 t 100% / Nrmalizatin Temperature 150 t 300 (adjustable) nductivity t TDS nversin factr 040 t 100 Number f calibratin pints (Autmatic) Number f calibratin pints (Manual) Aut-ranging Hld Functin Memry Averaging/Stability (READY)/Aut-hld Input Display Pwer Requirements Dimensin Weight 4; Maximum 1 per range 5; Maximum 1 per range Yes Yes 50 data sets Selectable 6-pin rund cnnectr ustm Dual LD 110/220VA mains, 50/60 Hz 230 x 180 x 63 mm (meter nly); 395 x 260 x 90 mm (bxed) 750 gm (unit); 1250 gm (bxed) Nte: In presence f strng electric field, the accuracy in the wrst scenari culd be 5% 25

30 12 AESSORIES Replacement Meter and Accessries Item Descriptin ON 510 Bench nductivity/tds meter cmplete with cnductivity/tds electrde (E-ONSEN91W/ ) and integral electrde stand 2-ring Stainless Steel, Ultem bdy nductivity/tds Electrde with built-in temperature sensr (fr AT), cell cnstant k = 10, dimensin: 12x110 mm, 1m cable length Eutech Instruments Order de N Oaktn Instruments Order de N E-ON510/03S E-ONSEN91W /120VA pwer adapter, 50/60 Hz E-120-ADA /230VA pwer adapter, 50/60 Hz E-220-ADA alibratin Slutins Item Descriptin Eutech Instruments Order de N Oaktn Instruments Order de N 1,413 µs Kl alibratin Slutin in 480 ml leak-prf bttle (1 pint) E-ON-1413BT ms Kl alibratin Slutin in 480 ml leak-prf bttle (1 pint) E-ON-1288BT ,764 µs Kl alibratin Slutin in 480 ml leak-prf bttle (1 pint) E-ON-2764BT µs nductivity Sachets (20 units x 20 ml per bx) E-ON-447BS ,413 µs nductivity Sachets (20 units x 20 ml per bx) E-ON-1413BS ,764 µs nductivity Sachets (20 units x 20 ml per bx) E-ON-2764BS ,000 µs nductivity Sachets (20 units x 20 ml per bx) E-ON-15000BS Nte: Slutins have ±1% accuracy at 25 Sachets are individually sealed, single use puch cntaining 20 ml f fresh, cntaminatin free calibratin slutin 26

31 13 NOTE: ONDUTIVITY AND TDS SOLUTIONS HAVE ±1% AURAY AT 25 ADDENDUM 1: IBRATION TIPS Yu nly need ne calibratin fr measurement thrughut the entire range f the meter If a range was nt calibrated, the meter autmatically detects the clsest range calibrated and uses that calibratin infrmatin Hwever, nly the ranges that were calibrated have maximum accuracy If yu are measuring in ranges near t r greater than 20 ms (10 ppt), r near t r lwer than 100 µs (50 ppm), calibrate the meter at least nce a week t get specified ±1% FS accuracy If yu are measuring in the mid-ranges and yu washed the prbe in deinized water and stred it dry, calibrate the meter at least nce a mnth Wet the prbe fr 10 minutes befre calibrating r taking readings t saturate the prbe surface and minimize drift If yu make measurements at extreme temperatures, calibrate the meter at least nce a week Yu shuld nly use the cnductivity/tds prbe specified fr the meter This prbe has a built-in temperature sensr If yu use a different prbe withut a temperature sensr, yu must measure the slutin temperature separately and manually enter the slutin temperature (see manual temperature cmpensatin sectin) 14 ADDENDUM 2: ULATING TDS ONVERSION FATORS Yu can calibrate yur meter using TDS calibratin standard slutins The calibratin standard nly needs t give the TDS value at a standard temperature such as 25 T determine the cnductivity-t-tds cnversin factr use the fllwing frmula: Factr = Actual TDS Actual 25 Definitins: Actual TDS: Value frm the slutin bttle label r as a standard yu make using high purity water and precisely weighed salts Actual nductivity: Value measured using a prperly calibrated nductivity/temperature meter Bth the Actual TDS and the Actual nductivity values must be in the same magnitude f units Fr example, if the TDS value is in ppm the cnductivity value must be in µs; if the TDS value is in ppt the cnductivity value must be in ms heck yur factr by multiplying the cnductivity reading by the factr in the abve frmula The result shuld be in TDS value 27

32 15 ADDENDUM 3: ULATING TEMPERATURE OEFFIIENTS T determine the temperature cefficient f yur sample slutin use this frmula: Where: tc = Temperature cefficient 25 = 25 T1 = nductivity at Temp 1 T2 = nductivity at Temp 2 T 1 = Temp 1 T 2 = Temp 2 NOTE: A cntrlled temperature water bath is ideal fr this prcedure 1 Immerse the prbe int a sample slutin and adjust the temperature cefficient t 0% (that is, n cmpensatin) by perfrming the fllwing: A Frm measurement mde, press the key t enter int [] mde B Use MI/ r MR/ key until the lwer display shws P50 Press key twice The lwer display reads to and the upper display shws the temperature cefficient value D Press the MR/ key until the upper display shws 00 E Press key t cnfirm the value F Press A/ key t return t measurement mde 2 Wait fr 5 minutes Nte T 1 and T1 (cnductivity at T 1 ) 3 nditin the sample slutin and prbe t a temperature (T 2 ) that is abut 5 t 10 different frm T 1, and nte the cnductivity reading T2 NOTE: Recrd yur results fr future reference Ideally T 1 and T 2 shuld bracket yur measurement temperature, and shuld nt different by mre than 5 4 alculate the temperature cefficient f yur slutin accrding t the frmula shwn abve 5 Enter the temperature cefficient yu calculated int the meter by repeat step A t Use MI/ r MR/ key t set the desired value Press key t cnfirm selectin and then press / key t return t measurement mde The calculated temperature cefficient will nt be applied t all the meter readings 28

33 16 ADDENDUM 4: METER FATORY DEFAULT SETTINGS Type Parameter Default Remarks P11 Viewing calibratin slutin N calibratin data fr first range P12 N calibratin data fr secnd range P13 N calibratin data fr third range P14 N calibratin data fr furth range P15 N calibratin data fr fifth range P21 Viewing prbe data 1000 N ffset fr effective cell cnstant (first range) P N ffset fr effective cell cnstant (secnd range) P N ffset fr effective cell cnstant (third range) P N ffset fr effective cell cnstant (furth range) P N ffset fr effective cell cnstant (fifth range) P31 Ready indicatr / Aut-hld READY/ON Ready indicatr n; Aut-Hld ff P32 Select / F Degrees elsius P33 AT n r ff AT YES P34 TDS factr 05 Adjustable frm 04 t 10 P41 Temperature cefficient 21 % per Adjustable frm 0 t 10% P42 Nrmalizatin temperature 25 Adjustable frm 15 t 30 P50 Aut r manual calibratin Aut YES Aut r manual P51 Single r multi-pint calibratin Single-pint YES Single r Multi-pint calibratin P60 ell cnstant 10 Select frm k=01, 10 r 10 P70 Factry default N Retains yur current settings 29

34 17 WARRANTY The ON 510 bench meter is supplied with a 3-year warranty frm manufacturing defects and electrdes fr 6 mnths frm the date f purchase If repair r adjustment is necessary and has nt been the result f abuse r misuse within the designated perid, please return freight pre-paid and crrectin will be made withut charge Eutech Instruments/ Oaktn Instruments will determine if the prduct prblem is due t deviatins r custmer misuse Out f warranty prducts will be repaired n a charged basis Exclusins The warranty n yur instrument shall nt apply t defects resulting frm: Imprper r inadequate maintenance by custmer Unauthrized mdificatin r misuse Operatin utside f the envirnment specificatins f the prducts 18 RETURN OF ITEMS Authrizatin must be btained frm ur ustmer Service Department r authrized distributr befre returning items fr any reasn A Return Gds Authrizatin (RGA) frm is available thrugh ur Authrized Distributr Please include data regarding the reasn the items are t be returned Fr yur prtectin, items must be carefully packed t prevent damage in shipment and insured against pssible damage r lss Eutech Instruments/ Oaktn Instruments will nt be respnsible fr damage resulting frm careless r insufficient packing A restcking charge will be made n all unauthrized returns NOTE: Eutech Instruments Pte Ltd/ Oaktn Instruments reserves the right t make imprvements in design, cnstructin, and appearance f prducts withut ntice 30