SC-300 Manual
Contents
1. Calculate the volume of titrant used V using the Syringe Starting volume minus final volume e g Burette final volume minus starting volume e g V 5 0 mL 3 5 mL 1 5 mL 2 The free SO content is calculated in units of parts per million ppm or mg L as 64 V N 1000 ppm mg L Free SO ET Where V mL SO Titrant needed to reach the endpoint N normality concentration of the Titrant and S mL of your wine sample Tf you use a 25 mL wine sample as directed and the SO Titrant s normality is 0 0156 as supplied in the kit then the calculation is simply ppm mg L Free SO 20 V i e 20 times V 1 64 mg SO2 mmol SO2 V mL N meq mL 1000 mL L 2 meq mmol SO2 S mL SC 300 manual 11 Version 2 1c Measuring Total SO by Titration optional requires 1N NaOH l Place 25 mL wine or must in the titration vessel See Figure 6 2 Add 10ml 1N sodium hydroxide Vinmetrica Part number SC 100 17 and mix well Let stand approximately 10 minutes 3 Using the transfer pipettes add approximately 8 mL of the Acid Reagent and 2 mL of the Reactant solution to the vessel Remember that if you are using the transfer pipettes in the kit 2 mL is the amount that fills the bulb with a vigorous squeeze so dispense four of these for the Acid Reagent Proceed from step 5 in the Free SO procedure above The result calculated will be total SOx rather than free SO in parts per million ppm or2. Sometimes the instrument may pick up noise from its environment particularly if you handle it at the last second while it s trying to achieve a stable reading This sensitivity is usually only an issue during calibration 3 If values appear to drift leave the electrode in the pH 4 01 reference solution for 30 minutes 4 If you intend to read pH values in samples that are at a different temperature than ambient it s best to have your reference solutions at that temperature also before calibrating 5 If the displayed pH value is within 0 5 pH units of the target but the CAL light fails to flash in the expected ready to calibrate manner you can try the force calibrate feature available in firmware 3 0 6 and higher described in the manual under Calibration of pH 6 If the displayed pH value is outside of the default tolerance of 0 5 pH but not more than 1 5 pH units you can temporarily broaden this tolerance to get calibration to go See Test Mode stage 14 in Appendix A available in firmware 3 0 6 and higher described in the manual under Calibration of pH Call or Email us for help if you need it SC 300 manual 21 Version 2 1c 7 Finally refer to the next FAQ question if these steps do not help What should I do if my pH electrode is acting sluggish erratic and is difficult to calibrate Reconditioning and cleaning of pH electrodes Even in normal use and storage performance of pH electrodes
3. The de vice should indicate STOP with its red LED and buzzer or beeper If this does not happen there may be a problem with the instrument contact us for more information 3 Connect the electrode and put it in about 20 mL of distilled water add about 1 ml half a bulb squeeze of each of the acid solution and the reactant and swirl in the usual way keeping constant motion The instrument may or may not indicate STOP as above If it does not add a drop of the SO Titrant solution This should make the STOP condition occur If it doesn t you may have an electrode problem read in the next section below how to fix this Now add one drop of a concentrated sulfite solution 1 10 is fine and verify that the STOP signal ends and the PROCEED light illuminates If this happens your electrode is probably OK as well 4 Finally you can check your SO reagents with the ascorbic acid vitamin C test located on our website vinmetrica com FAQ Preconditioning of the electrode Note as of October 2013 all SO2 electrodes are shipped pre conditioned so this procedure should not normally be needed Sometimes when the SO electrode is first shipped it can be shipped hot A hot electrode is one that is overly sensitive as indicated by high readings and STOP conditions when inserted into solutions that should be giving no signal like pure water or water plus reactant and acid with a drop of 10 KMBS added If your electrode shows this behavio
4. Vinmetrica SC 300 Kit User Manual Oinmetrica The Vinmetrica SC 300 is a simple and robust device that provides high accuracy in determination of sulfite SO2 pH and titratable acidity TA levels in wine These are essential parameters to control in the effort to make high quality wines Table of Contents Manae PTO CG WI E Eeee EE EEE cunt sadeumnsde nent 2 Tanes yon FH MC aa E E EE EE E 2 Woy Fest Ior SO PH and TA eccriene E EEE E 3 Po Oi CC O E E A E E A E E E E E NE 4 S e A E E E E E 5 Setting up the SC 300 for the first UME reise fee vaacnes dee desncsvancestoceteancavaacnerdceleswessaasentecedtaeeevasens 5 IPEDS CRUD CTV EC CF ANON 650g ch geno ncrece ane ecidewed esos vaste vopnaetscoasen se sate eetseoan nase votaaats evan sNiieevobbaeitescnentcenstoeet 7 I OCCU Sco E E ee eee seme eect eee seme ee cee eee 9 Measuring Pree Sulfite 502 by Titrat OM viiwseiwasccccacenesesassavasedenenedvesensesaaan aveawacoueaadeneweceeseces 9 Measuring Total Sulfite S02 Dy Titration eesessseeeennsssssssseeeresssssssseerrsssssssseerrsssssssseeeeeo 12 GT Draton Ot PH cscarnir ap E REEE E AR EEEE E RSi 12 UNM ASAT 9 s P A A AA E EAE E AN EEE A 13 Measuring Titratable Acidity TA by Titration ccccccccccccssssseeecceeeeeeaeeeseeeeeeeeesaeeeeeees 14 FANS AMY UN E E E vast oatensatnagieaad oaeoaeneside sac E 16 Warranties Liabilities amp Hazards ccccccccsscsssscccssssceccussscsecussscaccsescaceuseseaceusese
5. SC 100 17 3 Optional Deluxe Lab Accessory Kit which includes magnetic stirrer burette 1OmL or 25mL lab support stand and electrode holder Available from Vinmetrica Part Number SC 300 9 https vinmetrica com product the deluxe lab accessory kit 4 Optional Sodium Hydroxide solution IN concentration if you want to do total SO Available from Vinmetrica Part number SC 100 7 SC 300 manual 2 Version 2 1c Why Test for SO pH and TA Testing for sulfite SO2 is crucially important for making sure your wine does not spoil by oxidation or from microbial growth Having the proper SO level in your wine gives you this protection By monitoring your SO levels you can make adjustments when needed especially before starting primary fermentation after malolactic fermentation has completed after racking or when ready to bottle To correctly adjust sulfite you need values for your current Free SO2 level and your wine s pH both of which can be measured with the Vinmetrica SC 300 analyzer The key parameter in protecting your wine is Molecular SO2 which for most wines should be at 0 8 ppm mg L following primary fermentation This in turn depends on the Free SO it can also be referred to as unbound SO and the pH Overall you can reach your target Molecular SO2 by measuring and adjusting your free SO levels and considering your wine s particular pH See Table 1 Table 1 Free SO concentrations necessary to attain 0
6. mg L Calibration of pH l Be sure the pH electrode is attached to the unit then select CAL mode by pressing the MODE button until the CAL LED illuminates 2 Choose a calibration set that corresponds to the range you are working in Usually for wine this will be at pH values below 4 so use the 4 7 set If you have a source of a pH 3 00 reference solution you can use this in place of pH 4 s Rinse the electrode with DI water shake or blot off excess liquid gently and place the electrode into a small vessel like the pH 4 Reference Solution cap containing one of the reference solutions e g pH 4 01 4 The instrument will determine which calibration solution is being used and will display the apparent pH value This may be different by as much as 0 40 from the value of the reference solution e g the LCD may display 4 41 when the pH electrode is sitting in the pH 4 01 reference solution When the pH level is sensed as stable the nominal value is shown on the display flashing and the CAL LED flashes to convey that calibration for this value is ready Press the ENTER button to accept the calibration 5 The display stops flashing scrolling the message bood CAL and four beeps are rapidly sounded to indicate success Note if an error occurs during this process the message bAd CAL will scroll and a single beep will sound the instrument will then continue to wait for a SC 300 manual 12 Version 2 1c stable
7. sound as usual Otherwise the message bAd CAL will scroll and a single beep will sound In that case you can return after the next step and try PH4 again e The display will then show PH7 Place your pH electrode in the pH 7 00 reference solution and press ENTER then repeat the procedure in step d Measuring pH l Make sure the pH electrode is attached Calibrate it as described above if necessary Select pH mode with the MODE button 2 Rinse the pH electrode with DI water Gently shake off or carefully blot away excess liquid 3 Place the electrode in the solution to be tested Be careful not to let the electrode strike any surfaces SC 300 manual 13 Version 2 1c 4 Allow the pH reading to stabilize Typically this takes about 10 15 seconds Read the pH value on the display Note Once you ve completed the pH test you can start the TA test Start with precisely a 5 mL wine sample before beginning the pH amp TA combined measurement You can use a clean 5 mL sampling pipette provided in the kit to pipette this amount Measuring Titratable Acidity TA by Titration 1 If you are working with a sample of must we recommend homogenizing your sample in a blender before proceeding otherwise your TA values can be very inaccurate Take 100 mL or more of your must and put it in a blender on high for 30 seconds Allow solids to settle for 2 minutes before sampling or use a cheese cloth or mesh strainer to remove solids 2 Fill the
8. syringe by drawing up the TA Titrant 0 133N NaOH Expel bubbles and set the plunger on the syringe to a readable point preferably the 5 0 mL point Note the 5 0 mL setting allows determination of up to 10 g L TA in a standard 5 mL wine sample If you are using the burette use the syringe to dispense the TA titrant into the top of the burette Make sure the burette stopcock is in the closed the red handle is horizontal position When filling the burette make sure the TA titrant has completely filled the bottom of the burette including the tip Sometimes bubbles can be trapped in the tip of the burette but can usually be dislodged by opening and closing the stopcock while the burette is above a waste container If you spill any TA titrant on the outside of the burette be sure to clean it up with a paper towel or dry rag If the spilled titrant is not cleaned from the outside of the burette you may introduce these spilled titrant droplets into the wine sample leading to an inaccurate reading Be sure to record your starting burette or syringe volume Caution the TA Titrant is caustic and can cause damage to clothing skin and eyes We recommend use of laboratory safety glasses and latex or nitrile gloves during this procedure If any solutions contact skin or eyes flush with plenty of water 3 Place 5 0 mL wine or must in the titration vessel 100 mL polypropylene beaker We recommend using the 5 mL pipette provided in the kit draw sample up to
9. 8 mg L Molecular SO at a designated pH FreeSO2 ppm 13 16 21 26 32 40 so 63 79 99 125 We recommend using a sulfite calculator for determining how much sulfite to add to your wines after taking a sulfite measurement with the SC 300 Analyzer Kit Winemaker Magazine s Sulfite Calculator at http winemakermag com guide sulfite can walk you through the process See Appendix B for more information on how to adjust your wine for sulfite Monitoring your wine s pH is especially important for the first few months of the wine making process Proper pH and Titratable Acidity TA levels influence mouth feel and provide wine stability During malolactic fermentation the pH can increase somewhat and should be monitored Typically wine pH and TA are inversely related when pH goes up TA goes down and vice versa Adjustments may be made to your wine to prevent wine instability See Appendix B for more information on adjustments SC 300 manual 3 Version 2 1c Theory of operation Sulfite S02 The SC 300 with the SO electrode and reagents provided can be used to determine sulfite or SO2 levels in wine musts and other samples It relies on the Ripper titration based on the quantitative reaction of the SO with iodine generated during the titration which oxidizes the SO gt in the sample under acid conditions IO 51 6H gt 3L 3H O generation of iodine from iodate SO bL H2O gt 21 SO 2H reactio
10. ESS OR IMPLIED INCLUDING WITHOUT LIMITATION ANY WARRANTIES OF MERCHANTABILITY NONINFRINGEMENT OR FITNESS FOR A PARTICULAR PURPOSE SAID WARRANTIES BEING EXPRESSLY DISCLAIMED 2 Buyer agrees that its sole and exclusive remedy against Vinmetrica shall be limited to the repair and replacement of Materials or parts of Materials provided Vinmetrica is promptly notified in writing prior to the expiration of the warranty period specified above of any defect Vinmetrica s liability for any damages due Buyer shall be limited to the purchase price of the Materials 3 VINMETRICA S MAXIMUM LIABILITY FOR ALL DIRECT DAMAGES INCLUDING WITHOUT LIMITATION CONTRACT DAMAGES AND DAMAGES FOR INJURIES TO PERSONS OR PROPERTY WHETHER ARISING FROM VINMETRICA S BREACH OF THESE TERMS AND CONDITIONS BREACH OF WARRANTY NEGLIGENCE STRICT LIABILITY OR OTHER TORT WITH RESPECT TO THE MATERIALS OR ANY SERVICES IN CONNECTION WITH THE MATERIALS IS LIMITED TO AN AMOUNT NOT TO EXCEED THE PRICE OF THE MATERIALS IN NO EVENT SHALL VINMETRICA BE LIABLE TO BUYER FOR ANY INCIDENTAL CONSEQUENTIAL OR SPECIAL DAMAGES INCLUDING WITHOUT LIMITATION LOST REVENUES AND PROFITS HAZARDS AND TOXICITY All Materials offered by Vinmetrica are intended for use by individuals who are familiar with laboratory procedures and their potential hazards The Materials contain chemicals which may be harmful if misused Due care should be exercised with all Materials to prevent direct human c
11. H close to what titration The red STOP swirl gently add TA Titrant opening the burette you expect your wine is at LED will be lit and the with other hand stopcock valve You are ready to titrate instrument will be beeping Verify that the pH is less than 7 and the green PROCEED LED is lit see Figure 14 If the pH is greater than this and or the red STOP LED is lit and the beeper sounds your sample has less than 0 1 g L TA and there is no need to proceed Titrate the sample by adding the TA Titrant drop wise from the syringe or burette being sure to note the starting volume mark on the syringe or burette During the titration the pH will gradually rise from its starting value below 4 usually As you approach pH 7 go slowly in adding successive drops of titrant so as not to overrun the endpoint Be sure to mix thoroughly after each successive drop of titrant Take the endpoint as the first addition of TA Titrant that causes the pH to stay above 8 2 for longer than 15 seconds The red STOP LED and the beeper will provide additional indication of the endpoint See Figure 15 Read the endpoint volume off of the syringe or burette To silence the beeper after the endpoint select pH mode or turn off the instrument Calculate the TA value as V x 0 133 x 75 TA g LTartaric r SC 300 manual 15 Version 2 1c where V mL Titrant needed to reach the endpoint 0 133 normality of the Titrant mL sample If you us
12. be made by diluting 1 mL of the SO Acid Solution with 20 mL DI water or 0 1M nitric acid HNO3 for 1 hour Rinse with DI water then place in pH 4 reference solution for 5 minutes Try to recalibrate If this does not work try remedy 4 4 Soak in 1 10 dilution of bleach in a 0 1 0 05 solution of liquid detergent in hot water with vigorous stirring for 15 mins Rinse with DI water then place in pH 4 reference solution for 5 minutes Try to recalibrate Cleaning the pH electrode s glass membrane The glass bulb is a thin membrane of a special kind of glass that actually does the job of SC 300 manual 22 Version 2 1c responding to the pH of the solution It can sometimes become dirty and poorly responsive l Immerse electrode tip in 0 1M HCI see above for how to make for about 15 secs rinse with distilled water then immerse in 0 1M NaOH you can use a little of your TA Titrant for this for another 15 sec Cycle the electrode through these solutions several times rinsing with DI water in between then rinse and check for performance in pH buffer 4 00 and 7 00 2 Some other tricks protein deposits can be removed by soaking in pepsin in 0 1M HCI for 15 mins Inorganic deposits may be removed by soaking in 0 1M tetrasodium EDTA solution for 15 mins Grease and oil deposits may be removed by rinsing the electrode in mild detergent in methanol solution Instrument test You want to be sure that the instrument is respon
13. connector This can be used with certain electrodes for example galvanic oxygen probes potassium or sodium electrodes or to view the raw voltage reading of a pH electrode In this mode when the red STOP LED is illuminated the values on the screen are negative otherwise the values are positive SC 300 manual 7 Version 2 1c 6 TA mode This is for titration in determining titratable acidity TA As in the pH mode the pH is displayed and the pH electrode must be attached The green PROCEED LED is lit if the pH is below 8 2 while the red STOP LED is lit if the pH is 8 2 or greater see below under Measuring TA by Titration T CAL mode This is for calibrating the pH electrode which must be attached The display initially shows CAL for a few seconds as it prepares to read pH and lets readings settle Thereafter the display shows the measured pH level with two decimal places 8 Calibration works with one of the following reference calibration sets pH 4 01 and 7 00 or 4 7 pH 7 00 and 10 00 or 7 10 pH 3 00 and 7 00 or 3 7 Vinmetrica recommends use of the pH 4 7 Reference Solution set provided with the kit 9 The magnetic stirrer Included in the SC 300 Pro Kit or bought separately has two modes Pressing the light bulb button on the magnetic stirrer activates a light underneath the sample and the stirrer The power button activates just the stirrer After pressing either button the stirrer remains activ
14. crewed SC 300 by pushing it straight on into place on the BNC connector Avoid a twisting motion 5 SO electrode Remove any protective cover from the electrode tip some electrodes are shipped without one This cover is for shipping protection and need not be used routinely Put the electrode on its side or hang it from an electrode stand if you have one The SO electrode is sturdy with its plastic housing but do take care not to let things touch or strike the platinum wires they are somewhat fragile and will break if bent and straightened repeatedly SC 300 manual 5 Version 2 1c Electrode care When done always rinse with DI water and let air dry There is no need to store the SO electrode in any kind of solution 6 pH electrode Attach the pH electrode via the BNC connector on the top of the SC 300 see Figures 2 amp 3 A note about the pH electrode The pH electrode is fragile and should always be handled carefully Remove the liquid storage bottle by unscrewing the cap first then gently pulling the bottle followed by the cap off the electrode Rinse the electrode in a little distilled water before each use Electrode care Do not touch the glass bulb nor attempt to wipe it with anything When necessary you may gently blot excess liquid away from the electrode surface but avoid directly touching it The pH electrode should always be kept in the liquid storage bottle with its pH storage solution available from Vinmetrica wh
15. ding correctly A quick test is to simply short out the electrode connector l Put the instrument in pH mode 2 Remove the electrode to expose the BNC connector at the back of the instrument Short out the terminals on the connector using a paper clip or similar metal piece to touch the center pin of the connector to its outer metal sheath 3 With the input shorted out the reading should be pH 7 00 0 50 If out of this range the meter is probably bad Contact us at info vinmetrica com or tel 760 494 0597 3 With the input shorted out the reading should be pH 7 00 0 05 If out of this range the meter is probably bad Contact us at info vinmetrica com or tel 760 494 0597 4 Bear in mind that this test is not 100 fool proof the instrument might still have trouble reading pH values different from 7 00 but generally if this test passes it is much more likely to be an electrode problem Help What do I do if my pH electrode was attached to my SC 300 when in SO mode Is my pH electrode broken No don t worry your pH meter should still work To fix it leave your pH electrode in the pH 4 reference solution for an hour and it should return to normal function Enabling SO2 mode with the pH electrode attached could cause the pH electrode to wear out more quickly Because of its design SO2 mode cannot be accessed unless you press ENTER after pressing the MODE button this is another safeguard we installed to preve
16. e 5 mL of sample as directed and the Titrant is 0 133 N as supplied then the calculation is simply TA 2 x V i e 2 times V Note to express these values as tartaric acid divide by ten e g if the TA is 7 1 g L that is equivalent to 0 71 tartaric acid Finishing up l Turn off the instrument 2 Rinse the SO electrode and syringe with distilled water Let air dry 3 Be sure to rinse and store the pH electrode in its storage solution as directed under Setting up the SC 300 for the first time item 6 4 Store all reagents tightly capped and away from heat and sunlight gt Discard waste samples and solutions in accordance with local regulations Acidic solutions can be neutralized by slow addition of baking soda sodium bicarbonate with stirring until effervescence ceases Technical assistance info vinmetrica com tel 760 494 0597 SC 300 manual 16 Version 2 1c WARRANTIES AND LIABILITIES l The materials provided in the kit as described on pages 1 and 2 above Materials are warranted as follows The SC 300 instrument SO electrode and non reagent accessories are warranted against defects in workmanship for 24 months from date of purchase The pH electrode is warranted for 1 year The reagents are warranted to perform as described herein up until any stated expiration date or 6 months after purchase whichever is later THE WARRANTIES IN THESE TERMS AND CONDITIONS ARE IN LIEU OF ALL OTHER WARRANTIES EXPR
17. e first time l The SC 300 See Figure 1 runs on two standard AA batteries alkaline cells recommended To insert the batteries open the battery housing on the bottom of the back of the unit by removing the two screws and gently prying off the lid Install the batteries with the negative end contacting the coiled springs and the positive end contacting the raised metal inserts then close the housing If desired you can prop the unit up using its folding stand PA Low Battery Detection When the battery level is getting low the instrument will show a low battery icon on the upper left side of the display but continues to operate without impairment to any function Replace the batteries as soon as practicable When the battery level drops too far the instrument does not operate It rapidly flashes the low battery icon for 3 0 seconds beeps and shuts itself off 3 Auto Shut off The SC 300 shuts off after 30 minutes If this happens unexpectedly just press the POWER button to resume from where you were 4 Electrodes When directed to do so attach the desired electrode SO2 or pH Figures 2 amp 3 via the proper connector protruding from the top on earlier model SC 300s there is just a single connector for both electrodes Be sure to secure the electrode plug to the BNC connector to insure proper function Figure 2 Attach the SO2 electrode Figure 3 Be sure the pH to the phono plug connector on the electrode attachment is s
18. e for 60 seconds a feature to conserve its batteries If during the titration it turns off simply press the button again for it to continue We recommend using the light mode because it helps us indicate when the stirrer stops Plus when doing TA titrations watching the wine turn from deep red to dark green is cool Note When using the magnetic stirrer be sure that the electrode does not touch the spinning stir bar as there is a slight chance that it can damage the glass bulb of the pH electrode or the platinum wires of the SO electrode If you are using the Vinmetrica Electrode Holder adjust the electrode s height so that its probe end is above the level of the stir bar SC 300 manual 8 Version 2 1c Procedures Measuring Free SQ by Titration 1 With the electrode disconnected turn on the instrument and select SO2 mode using the MODE button Press ENTER to confirm selection of SO2 mode Figure 4 The display should show a value less than 20 usually 0 0 Now attach the SO2 electrode Figure 4 Once in SO2 Figure 5 Withdraw the Figure 6 Dispense 25 Figure 7 The transfer MODE the instrument titrant from its bottle mL of your wine into the pipette One full squeeze should read using a clean 5 mL titration beaker using the of the transfer pipette in Press Enter Press syringe If you are using 25 mL sampling pipette either the Acid solution ENTER to activate SO gt the glass burette use the Make sure this is clean or Reactan
19. e recommend using the 25 mL sampling pipette provided in the kit draw the sample up to the 0 mL mark and then dispense the sample into your titration vessel by letting the tip of the pipette touch the side of the vessel while the sample drains See Figure 6 NEVER pipette any reagents by mouth Also make sure the pipette you are using is completely clean before submerging into your wine sample Using the transfer pipettes see Figure 7 add about 2 mL Acid Reagent and 2 mL Reactant solution to the titration beaker the two transfer pipettes should come with red and yellow labels with red for the Acid Reagent and yellow for the Reactant It is not necessary to be extremely accurate in this step with these pipettes 2 mL is roughly the amount that fills the pipette up to the 2 mL mark after a single thorough squeeze of the bulb To preserve the shelf life of these reagents take care not to cross contaminate the transfer pipettes If they do get contaminated rinse them out with distilled water and let air dry Caution the Acid reagent is corrosive and can cause damage to clothing skin and eyes The reagents should not be ingested ALWAYS use safety glasses We recommend the use of laboratory latex or nitrile gloves during this procedure If any solutions contact skin or eyes flush with plenty of water If you are using a magnetic stirrer turn it on to stir at a moderate rate The Magnetic Stirrer operates at a suitable preset speed Make sure your
20. electrode 1s not struck by the spinning stir bar To prevent this we recommend using the Vinmetrica Electrode Holder to stabilize your electrode Rinse the electrode briefly with distilled water Insert the electrode into the titration beaker so that the tip is completely submerged to just above the circulation gaps cutouts at the tip of the electrode but above the level of the stir bar approximately half an inch from the bottom of the titration beaker If you are using the Vinmetrica Electrode Holder adjust it to a similar level If you are stirring manually begin now use a constant moderate swirling motion If the electrode is not held in a stand hold it against the side of the vessel with one finger and grasp the vessel with the remaining fingers so that the two move together See Figure 8 Verify that the current is less than 50 and the green PROCEED LED is lit See Figure 10 If the current is greater than this and or the red STOP LED is lit and the buzzer sounds your sample has less than 2 ppm SO and there is no need to proceed Verify that your SO2 has been preconditioned see step 3 in the Instrument Operation section of the manual Titrate the sample by adding the SO Titrant drop wise from the syringe See Figure 8 or from the burette See Figure 9 being sure to note the starting volume mark on the syringe or burette Try to accomplish the titration as rapidly as possible in 3 minutes or less but be caref
21. en not in use Rinse the electrode with DI water and gently blot or shake off excess water Push the electrode through the hole in the cap about an inch then gently screw the bottle onto the cap so that the electrode is in contact with the solution in the bottle SC 300 manual 6 Version 2 1c Instrument Operation 1 Disconnect any electrodes Turn on the instrument by pressing the POWER button briefly Note depressing the POWER button longer than two seconds at start up will cause the instrument to enter Test Mode see Appendix A The instrument will go through a power up sequence After a few seconds the instrument will start in whatever mode was last selected The mode is indicated by the yellow LED panel on the left Select the desired mode by pressing the MODE button 2 SO mode This is for titration in determining ppm of SO see below under Procedures The SO electrode must be used but do not attach the electrode yet Warning The pH electrode can be damaged by connecting it to the instrument in SO2 mode As a safety precaution you must press the ENTER button after selecting SO2 mode to confirm that the SO electrode is attached before the mode will be enabled However scrolling through the MODE selections such that you pass by the SO selection with a pH electrode attached is safe as long as you do not press ENTER to confirm the SO mode After pressing ENTER you should see the display show a value less than 50 usual
22. istilled water with a half bulb full of the acid solution for a few hours Now repeat the test from step 3 If it works great If not call us and we will try to troubleshoot or replace your electrode Technical assistance info vinmetrica com tel 760 494 0597 SC 300 manual 26 Version 2 1c
23. lator instrument s current amplifier is displayed as X XX volts X XX if less than 1 00 7 DAC Test None The Digital Analog Converter DAC is Disconnect probe cycled through its 32 levels Note Ignore red LED error indication 8 Battery Install two AA The battery voltage is displayed as X XX Voltage batteries volts 9 Character None Every ASCII character space to is Set displayed Due to the limitations of the 7 segment format some characters are not used by the software Display every possible digit and every decimal point s 11 Sound Test The beeper is turned on continuously 12 pH CAL None only firmware Displays current CAL values for pH 7 values v3 0 6 and later and 4 in mV Pressing ENTER cycles between these If a pH CAL reset has been done displays CAL value for pH 3 rather than 4 13 pH CAL None only firmware Displays PrES5 EnkEr Press reset v3 0 6 and later ENTER to reset pH CAL parameters to default values Message Good CAL r SE then scrolls 10 Number None The display cycles through showing 14 CAL None only firmware Displays E gL Eol then displays the tolerance v3 0 6 and later current value of the tolerance required to allow calibration Default is 0 5 pH units 1 e the displayed pH must be within 0 5 units of the target pH to allow calibration Pressing ENTER cycles between settings of 0 25 0 50 0 75 1 00 1 25 1 50 15 SO N
24. ly 0 0 and the green PROCEED LED should be on Now you can attach the SO electrode 3 Optional Pre condition the SO Electrode AIIl SO electrodes are pre conditioned at Vinmetrica before shipment Therefore normally you should skip this step If you think your electrode is not functioning properly you may try pre conditioning the electrode See Appendix C2 for more information on preconditioning the SO electrode 4 pH mode In this mode the meter measures the pH The pH electrode must be attached If the instrument has not yet been calibrated the message doCal scrolls across the screen and you will need to do a calibration see Calibration of pH below We recommend re calibrating the instrument for pH once each day of use or whenever the Reference solutions do not give the expected pH in pH mode Warning Be careful on earlier versions not to press ENTER when the pH electrode is attached while the instrument is in SO2 mode as this can potentially damage the pH electrode If this does happen and the pH electrode does not respond correctly place it into the pH 4 Reference solution for an hour and it should return to normal function With recent versions there are two separate connectors the pH electrode should be attached to the silver BNC connector 5 Potential mode Firmware version 3 1 1 and higher pH LED flashing In this mode the instrument displays the potential in volts coming from an electrode attached to the pH
25. may show deterioration over time which typically shows up as noisy erratic or sluggish electrode readings and or difficulty calibrating Assuming the meter itself is working see Meter test below then there are two main causes for this 1 Clogging of the reference junction most likely on Fouling of the glass membrane happens occasionally or after prolonged service The following procedures will often provide renewed stability and pH sensitivity If the electrode cannot be restored by one of these methods it needs to be replaced Unblocking the reference junction The reference electrode junction is usually the problem when the electrode can t calibrate in its expected ranges This junction is a fine pored frit that allows electrical contact of a reference electrode with the solution being tested It can become clogged over time l Soak electrode in hot NOT boiling water about 60 C for 5 10 mins Allow to cool to room temperature then place in pH 4 reference solution for 5 minutes Try to recalibrate If this does not work try remedy 2 2 Place the pH electrode into the pH storage solution available from Vinmetrica part number SC 200 10 or a solution of 2 5M KCl with optionally added 0 01M KHP at 60 C and allow electrode and solution to cool to room temperature then place in pH 4 reference solution for 5 minutes Try to recalibrate If this doesn t work try remedy 3 3 Soak in 0 1M HCI note this can
26. n of SO and iodine When all the SO is titrated at the endpoint excess iodine appears in solution This is detected as current with the SO electrode and signaled by audible and visual indicators The endpoint is much more sensitive than the starch color change commonly employed for Ripper titration and it is sharp and clear even when titrating red wines and musts From the known concentration of the titrant and its volume required to reach the endpoint the free SO is simply calculated pH and TA The SC 300 kit also provides a pH electrode and reagents for calibration and determination of pH and titratable acidity TA values in wines and other samples The pH value is simply determined by placing the calibrated electrode into a sample and reading the value TA is determined by titrating a 5 mL sample of wine to an endpoint pH of 8 2 with the TA titrant 0 13N NaOH from the syringe in the kit From the known concentration of the TA titrant and its volume required to reach the endpoint the TA is simply calculated results are in units of g L tartaric acid Potential measurements In versions 3 1 1 and higher of the firmware the SC 300 can display the voltage reading on an electrode attached to the pH connector This can be used with certain electrodes for example galvanic oxygen probes potassium or sodium electrodes or to view the raw voltage reading of a pH electrode SC 300 manual 4 Version 2 1c Setup Setting up the SC 300 for th
27. nt this from becoming a problem SC 300 manual 23 Version 2 1c Appendix C2 Troubleshooting SO Issues How stable are the reagents The SO reagents and the pH TA reagents are all warranted to last for 6 months We have found that in fact except for the TA Titrant our reagents are stable for well over 12 months if stored tightly capped out of the heat and direct sunlight And of course these reagents will last much longer if not cross contaminated with each other If the solutions become cloudy or show signs of microbial growth they should be replaced The TA Titrant can pick up atmospheric CO2 and lose potency over time so we recommend that you replace it every six months How can I check the accuracy of my reagents It s rare that the SO reagents go bad but if you are concerned about it you can run the Ascorbic Acid Test method located in the FAQ section of the website to check your SO reagents If you are worried about your TA Titrant you can run the KHP test also located on the Vinmetrica web site in the FAQ section under Manuals Tests and How To Videos at vinmetrica com FAQ I added the calculated amount of sulfite to my wine but the numbers are still low This is a common occurrence with several explanations any or all of which may be happening l Make sure you are using fresh sulfite powder Potassium metabisulfite degrades over time and that stuff you bought 2 years ago is probably bad now A Make s
28. one Disconnect SO gt Sets baseline value for SO2 mode Let Baseline electrode only fw message scroll 5 sec then press ENTER v3 1 0 and later SC 300 manual 19 Version 2 1c Appendix B Sulfite and TA Adjustments Using the Winemaker Magazine Sulfite Calculator Winemaker Magazine s Sulfite Calculator at http winemakermag com guide sulfite is an excellent tool for calculating how much sulfite should be added to your wine We will briefly go over the process here for some clarification l Select a Preferred method of Sulfite addition we recommend using a 10 solution of Potassium metabisulfite KMBS You can prepare this solution by weighing out 10g of KMBS and dissolving it in a FINAL volume of 100 mL DI water 2 Next choose the wine type red or white 3 Keep the Desired Molecular SO at 0 8 mg L and enter your wine s pH value hit your keyboard s Enter button after entering the value 4 After entering in your Desired molecular SO and your wine s pH the calculator will ask you to enter the Desired level of free SO The calculator already knows what this value is based on the data you entered and it should appear in the Notes section below the entry fields but the one fault of this app is that at least when we run it it won t tell you until you go through the calculation once So for now just enter 100 for the Desired level of free SO2 and proceed you will come back to this s
29. ontact Glassware can break and chemicals can splash during experiments Always use safety glasses We strongly recommend using nitrile or latex gloves and wearing long pants long sleeves and closed toed shoes Keep out of reach of children Viametuca 1945 Camino Vida Roble Suite Carlsbad CA 92008 www vinmetrica com 760 494 0597 info vinmetrica com Copyright 2010 14 Sportsman Consulting LLC DBA Vinmetrica All rights reserved SC 300 manual 17 Version 2 1c Appendix A Test Mode Test Mode provides various special functions that may be useful in testing or adjusting the device for example if troubleshooting is necessary e Test Mode is entered when the POWER button is pressed longer than 2 seconds while turning the instrument on Remove the pH electrode 1f it is attached Test Mode is organized into sections Press the POWER button briefly to move to the next section After the last section Test Mode restarts the first WARNING DO NOT MOVE THROUGH SECTIONS WITH THE pH PROBE ATTACHED This can damage the electrode Only connect the pH electrode if needed in section 2 or 4 Always remove the pH electrode before leaving these sections e Combinations of the yellow MODE LEDs are illuminated to indicate the section number as shown in the table below The Stop LED red is illuminated when an error is detected by the instrument The Proceed LED green is illuminated to indicate no error detected The green LED does no
30. pH level Repeat step 4 Following the baad CAL message the display will now show the calibrated pH value 6 Now rinse the electrode again and place it in the second member of the calibration set e g pH 7 00 reference solution Repeat the process to get a second baad LAL message Exit into pH or TA mode 7 Force Calibrate feature firmware v3 0 6 and later 1f your instrument displays an apparently stable pH value that is within 0 5 by default unless you have changed the CAL Tolerance value see Appendix A Test Mode 14 of the target 1 e 3 5 to 4 5 for pH 4 01 or 6 5 to 7 5 for pH 7 00 but the CAL LED does not flash within a reasonable amount of time 1 2 minutes at most typically you can force the instrument to accept the calibration by following these steps NOTE we recommend only using this as a last resort if normal calibration does not execute a Use the MODE button to select TA mode b Press and hold the MODE until the display goes from LAL to ce AL i e the C will change to lower case c c The display will then show PH4 Place your pH electrode in the pH 4 01 reference solution and press ENTER d The apparent pH will be displayed Allow it to come to a stable reading then press ENTER If the reading is within the Cal tolerance range default 0 5 pH as above but see Appendix A for Cal tolerance settings the Good CAL message will scroll and the four beeps will
31. r it generally can be fixed by pre conditioning as follows Ie First turn the power on and press the MODE button until the instrument is in SO2 mode then press ENTER Attach the SO electrode to the SC 300 analyzer Put 20 mL of distilled water deionized water in a beaker and add half a bulb squeeze of the acid solution half a bulb squeeze of the reactant solution and let the SO electrode sit in this solution 2 Then add one drop of 10 potassium metabisulfite solution KMBS to the beaker with the electrode in it Swirl gently The instrument LCD should now read 0 0 in units of nanoamps or close to it If it is reading significantly higher than 20 on the screen let the electrode sit in the solution for half an hour 3k After half an hour rinse the electrode with distilled water Put it in about 20 mL of distilled water Again add half a bulb squeeze of each of the acid solution and the reactant and swirl in the usual way keeping constant motion The instrument may or may not indicate STOP as above If it does not add a drop of the SO Titrant solution This should make the STOP condition occur If it doesn t you may have an electrode problem SC 300 manual 25 Version 2 1c 4 Now add one drop of KMBS solution 1 10 is fine swirl and verify that the STOP signal ends and the PROCEED light illuminates If this is the case you are done If the electrode is still hot and the PROCEED light does not illuminate let it sit in 20 mL of d
32. re various ways to do this We recommend adding tartaric acid for non grape wines fruit acids are sometimes used Use caution for if overdosed with added acid the wine becomes too tart Remember it s always easy to add more acid while it s not so easy to reduce acidity By measuring TA you can figure out how much tartaric acid to add without making your wine overly tart or sharp As a rough rule of thumb adding 1 g of tartaric acid per liter of wine will increase the TA by 1 g L 0 1 and reduce the pH by about 0 1 pH unit If your TA is too high before bottling you can try cold stabilization This results in precipitation of potassium acid tartrate potassium bitartrate to decrease the tartness Another method to decreasing your TA level is to add calcium carbonate or potassium carbonate CaCO3 or K2CQs3 For the chemically inclined we recommend Zoecklein s book Wine Analysis and Production which goes over theory and practice behind these adjustment techniques and many wine analytical techniques Appendix Cl Troubleshooting pH and TA Issues I can t calibrate the pH on my SC 300 When calibrating your pH electrode remember these points l The displayed pH may not be correct until after you press ENTER 2 If the instrument signals stable pH but displays Bad Cal after pressing ENTER try laying it flat on the table when the next stable signal is signaled press the ENTER button quickly without handling the instrument
33. sseussseaseusess 17 Appendix A owe 02 aL 01 eee ee ee eee eee 18 Appendix B Sulfite amp TA Adjustiments 0 ccc cccccccccssseeeeceeeeeeeeeeeaaaaaaaeeeeesseeeeeeeeeeeeeeeeeeeeaaaaaaas 20 Appendix C1 Troubleshooting pH and TA ISSues 00 cece ccc sesseeeeecceeeecaaeeeeeeeceeeeeaaas 21 Appendix C2 Troubleshooting SQ ISSUGS cc ccccccccccccccaesseseeccceeeescaeesseeeeceseeesaaaeseeeeeees 24 US Patent pending SC 300 manual 1 Version 2 1c Materials provided in the kit p lt Vinmetrica SC 300 SO2 pH controller unit Part number SC 300 1 SO Electrode Part number SC 100 3 blue polycarbonate housing 3 pH Electrode Part number SC 200 3 red or blue polycarbonate housing SO Reagent set Part number SC 100 2 SO Titrant solution 0 0156N Acid Reagent ae gt Reactant solution 5 pH TA reagent set Part number SC 200 8 pH 4 01 calibration solution pH 7 00 calibration solution TA titrant 0 13 N NaOH Two 5 mL syringes Figure 1 The SC 300 instrument with the SO Two 3 mL polyethylene transfer pipettes and pH TA electrodes One 25 mL serological pipette O oo ND One 5mL serological pipette 10 100 mL polypropylene beaker Things you will need Two standard AA batteries alkaline type 2 Distilled water which usually can be found at your local grocery store It s handy to have a wash bottle for rinsing Rinse bottle available from Vinmetrica Part number
34. t guarantee proper functioning it only indicates that no problem could be automatically detected The user should make careful observations to discern proper operation To exit Test Mode hold the POWER button down 5 10 seconds until the instrument shuts off If the device does not shut off after 10 seconds of holding down the button move to the next section by releasing then pressing again the POWER button briefly then try to exit again oe aa 1 Version None The version number of the instrument software is displayed The instrument goes through a None continuous burn in cycle exercising relay sound LEDs and display pH probe or precision An uncalibrated pH level is shown in two voltage source Do alternating parts First the integer not exceed 0 5 V portion of pH level is shown 1 to 14 Next three decimal places are shown Readings above 14 000 are shown as Readings below 0 000 are shown as SO probe or SO The SO current in nanoamperes is probe simulator e g displayed For values under 10 one 500 kOhm resistor decimal place is shown SC 300 manual 18 Version 2 1c zm Section Equipment Reid 5 pH Voltage pH probe or precision The raw voltage output from the voltage source Do instrument s pH amplifier is displayed as not exceed 0 5 V X XX volts Readings can range from 0 00 to 4 10 6 S02 Voltage SO probe or The raw voltage output from the SO probe simu
35. t should be MODE syringe to fill it before putting the pipette approximately 2 mL into your wine container 2 Fill the syringe by drawing up the SO gt Titrant the bottle with the blue label Figure 5 Expel bubbles and set the plunger on the syringe to a readable point preferably the 5 0 mL point Make sure the outside of the syringe 1s dry to minimize any inaccuracies Note the 5 0 mL setting allows determination of up to 100 ppm SO in a standard 25 mL wine sample If using a burette use the syringe to dispense the SO titrant into the top of the burette Make sure the burette stopcock is in the closed position 1 e the handle is horizontal When filling the burette make sure the SO titrant has completely filled the bottom of the burette including the tip Sometimes bubbles can be trapped in the tip of the burette but can usually be dislodged by opening and closing the stopcock while the burette is above a waste container If you spill any titrant on the outside of the burette be sure to clean it up with a paper towel or dry rag If the spilled titrant is not cleaned from the outside of the burette you may introduce these spilled titrant droplets into the wine sample leading to an inaccurate reading Be sure to record your starting burette or syringe volume refer to Burette Reading section under the Setup section for how to measure accurately SC 300 manual 9 Version 2 1c Place 25 mL of wine or must in the titration vessel W
36. tep in a moment to get the right answer see below 5 Now input the Current level of Free SO2 which you determined from measuring Free SO with the Vinmetrica SC 300 6 Finally enter the volume of wine to be corrected Choose liters or gallons we prefer liters because the answer is returned in mL 7 Now press the blue Calculate button Ignore the answer below the Amount of sulfite to be added and look below to the Notes section You should now see the message 1 The recommended level of free SO for this type of wine molecular SO2 amp pH is your value mg L 8 Go back to step 4 and enter this value for the Desired level of free SO 9 Press Calculate again to get the correct amount of sulfite to add The value will be in mL or fluid ounces of 10 sulfite solution or in grams if you use sulfite powder as your sulfite additive We recommend double checking your calculations Also be sure you are using fresh KMBS Once you have added the recommended amount of sulfite stir your wine thoroughly and take another SO measurement after waiting at least 30 minutes If the measurement matches the Desired level of free SO then you are done otherwise make incremental additions and repeated SO measurements until you reach your desired level SC 300 manual 20 Version 2 1c Adjusting TA in your wine If your wine s pH is too high and TA level is too low you may want to increase the acidity There a
37. the O mL mark then dispense the sample into your titration vessel by letting the tip of the pipette touch the side of the vessel while the sample drains For best accuracy do not blow out the liquid that remains in the tip Add about 15 ml of deionized DI water distilled water 4 Turn on the instrument and attach the pH electrode If necessary calibrate it as described above Select TA mode with the MODE button 5 If you are using a magnetic stirrer turn it on to stir at a moderate rate Be sure the stir bar will not strike the electrode in the following steps See Figure 13 SC 300 manual 14 Version 2 1c 10 Rinse the electrode briefly with DI water Insert the electrode into the titration vessel so that the tip is fully submerged to just above the circulation gaps cutouts at the tip of the electrode If you are stirring manually begin now use a moderate swirling motion If the electrode is not held in a stand hold it against the side of the vessel with one finger and grasp the vessel with the remaining fingers so that the two move together while swirling See Figure 12 l Figure 12 Manual stirring Figure 13 Automated Figure 14 Make sure that Figure 15 Once the pH technique Hold the stirring technique Turn on the green PROCEED arrives at or passes 8 20 electrode against the side of the magnetic stirrer add LED is lit You should be you are done with the the titration beaker and TA Titrant by slowly reading a p
38. ul near the endpoint so as not to overrun it here dispense one or two drops at a time Be sure to maintain stirring or swirling throughout the entire procedure If the magnetic stirrer turns off turn it back on SC 300 manual 10 Version 2 1c Figure 8 Manual stirring Figure 9 Automated stirring Figure 10 Make sure Figure 11 Once the device technique Hold the electrode technique Turn on the that the PROCEED beeps for 15 seconds or 20 against the side of the titration magnetic stirrer add SO2 LED is lit You should be sets of beep beep beaker and swirl gently add Titrant by slowly opening the reading close to 0 0 when you are done with the SO Titrant with other hand burette stopcock valve you first start You are titration The red STOP now ready to titrate LED will also remain lit 10 During the titration the LCD display will show transient currents the red STOP LED will briefly illuminate and the beeper will sound beep beep These transient indicators will last longer and longer as you approach the endpoint Figure 26 Take the endpoint as the first addition of Titrant that causes the display to exceed 50 and the red LED and beeper to stay on for longer than 15 seconds or a count of 20 sets of beep beep It is important to maintain stirring or swirling to detect the endpoint well Do not add titrant while the red STOP LED is lit Read the remaining titrant volume off of the syringe or burette 11
39. ure that you stir your wine well when you add sulfite If you pour a 10 solution of KMBS into your wine it sinks like a battleship A sample taken off the top will read low unless the wine is stirred gt A significant portion of the sulfite you added may have ended up bound particularly if your free SO was very low to begin with This bound SO does not show up when you measure free SOz and it is not protecting your wine You will need to add more sulfite until your free SO2 comes up to the right level Sometimes you must add 2 or even 3 times more sulfite than you first calculated I m getting strange results in SO mode how do I know if my instrument is working correctly We recommend that you always start in SO2 mode with the electrode disconnected After pressing ENTER to confirm SO mode then connect the SO electrode This avoids incorrect back ground settings that may make the instrument appear to be insensitive or unresponsive SC 300 manual 24 Version 2 1c For SO measurements with the SC 300 there are several quick tests you can do to make sure the instrument is not faulty E Be sure the battery is good per the manual s instructions Dy Remove the electrode to expose the phono connector at the back of the instrument Turn on the instrument and select SO mode Short out the terminals on the connector using a paper clip or similar metal piece to touch the center hole of the connector to its outer metal sheath
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